Reimplement the archived UI widget stack on the new element-tree system

The old widget system (archive/dusk/ui/) depended on infrastructure this
rewrite deleted -- a static X-macro element list, a 9-slice UI_FRAME, and
a global gamepad/keyboard focus stack -- so everything below is rebuilt
on top of the new native uielement_t pool + parent/child tree instead,
gamepad/keyboard-only (no mouse support exists in the input system).

New JS widgets (assets/scripts/), all pure composites of Label/Rectangle
following the Button.js pattern: Checkbox, Tab, Slider, Dropdown. Slider/
Dropdown expose a directionInput(dx, dy) hook so a menu can hand them
LEFT/RIGHT before falling back to cursor movement.

New Menu.js replaces the old global uifocus_t stack: a small push/pop
stack of Menu instances where only the topmost consumes CANCEL/ACCEPT/
direction input each tick (needed for nested modals -- a Settings
sub-page menu plus a "discard changes?" Confirm can be open at once).
Held-direction repeat timing matches the old 0.5s delay / 0.1s repeat.

New overlay composites (added via a new UI.addOverlay()/UI.removeOverlay(),
always drawn/updated after normal roots): FpsCounter, ConsoleOverlay
(one Label per console history line, driven directly rather than via
add() since History (16) exceeds the 8-children-per-element cap), Crop
(letterbox/pillarbox bars), and Fullbox (a reusable tweened full-screen
fade covering both the old fullbox and transition effects -- reuses
shared instances rather than allocate-and-dispose, since disposing an
element from inside its own render() callback risks the same JerryScript
refcount corruption hit earlier in this rewrite).

New Confirm.js (Yes/No dialog) and Settings.js (+ SettingsGeneral/
SettingsInput sub-pages) built on Menu. Display/Audio settings pages are
intentionally not ported -- neither had a real backing engine system
even in the old code. Frame is a flat Rectangle for now, not real 9-slice
(a genuinely bigger native lift, deliberately deferred).

Small native binding additions needed by the above, each with its own
unit test: Time.renderDelta, Console.lineCount/getLine/visible/
consumeDirty, a new Screen module, a new Locale module, Input.deadzone,
a new Save module, and Label.color (was missing entirely). Also fixes
a real gap from the UI.addOverlay() work: uiElementDispose() wasn't
removing disposed elements from the new overlay root array, which would
have left dangling ids behind.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.github/workflows/test.yml

@@ -33,3 +33,74 @@ jobs:
             libssl-dev
       - name: Run tests
         run: ./scripts/test-linux.sh
+
+  # Emulator smoke tests: boot the built disc/EBOOT for a fixed window and
+  # confirm the emulator doesn't crash. Not yet verified against a real
+  # runner (no CI run has exercised these) -- continue-on-error so a
+  # flaky/broken emulator step doesn't block the required Linux test job.
+  run-tests-gamecube-dolphin:
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    container:
+      image: ghcr.io/extremscorner/libogc2:latest
+    steps:
+      - name: Install Node.js
+        run: apt-get update && apt-get install -y nodejs
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Install additional dependencies
+        run: |
+          apt-get install -y \
+            python3-pip python3-polib python3-pil \
+            python3-dotenv python3-pyqt5 python3-opengl xorriso \
+            dolphin-emu xvfb
+          dkp-pacman -Syu --noconfirm
+          dkp-pacman -S --needed --noconfirm \
+            gamecube-sdl2 ppc-liblzma ppc-libzip \
+            gamecube-tools ppc-libmad ppc-zlib-ng ppc-bzip2 ppc-zstd
+      - name: Build GameCube ISO and boot it in Dolphin
+        run: ./scripts/test-gamecube-dolphin.sh
+
+  run-tests-wii-dolphin:
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    container:
+      image: ghcr.io/extremscorner/libogc2:latest
+    steps:
+      - name: Install Node.js
+        run: apt-get update && apt-get install -y nodejs
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Install additional dependencies
+        run: |
+          apt-get install -y \
+            python3-pip python3-polib python3-pil \
+            python3-dotenv python3-pyqt5 python3-opengl xorriso \
+            dolphin-emu xvfb
+          dkp-pacman -Syu --noconfirm
+          dkp-pacman -S --needed --noconfirm \
+            gamecube-sdl2 ppc-liblzma ppc-libzip \
+            gamecube-tools ppc-libmad ppc-zlib-ng ppc-bzip2 ppc-zstd
+      - name: Build Wii ISO and boot it in Dolphin
+        run: ./scripts/test-wii-dolphin.sh
+
+  run-tests-psp-ppsspp:
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Setup pspdev
+        uses: ./.github/actions/setup-pspdev
+      - name: Install PPSSPPHeadless build dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y git cmake ninja-build libsdl2-dev zlib1g-dev
+      - name: Build PPSSPPHeadless
+        run: |
+          git clone --recursive --depth 1 https://github.com/hrydgard/ppsspp.git /tmp/ppsspp
+          cmake -S /tmp/ppsspp -B /tmp/ppsspp/build -DCMAKE_BUILD_TYPE=Release
+          cmake --build /tmp/ppsspp/build --target PPSSPPHeadless -- -j$(nproc)
+          echo "PPSSPP_HEADLESS_BIN=/tmp/ppsspp/build/PPSSPPHeadless" >> "$GITHUB_ENV"
+      - name: Build PSP EBOOT and boot it in PPSSPPHeadless
+        run: ./scripts/test-psp-ppsspp.sh

CMakeLists.txt

@@ -13,6 +13,7 @@ cmake_policy(SET CMP0079 NEW)
 # set(FETCHCONTENT_UPDATES_DISCONNECTED ON)
 
 option(DUSK_BUILD_TESTS "Enable tests" OFF)
+option(DUSK_NETWORKING "Enable networking support" OFF)
 
 set(DUSK_GAME_NAME "Dusk" CACHE STRING "Game display name")
 set(DUSK_GAME_AUTHOR "YourWishes" CACHE STRING "Game author / coder")
@@ -90,6 +91,12 @@ target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME}
     DUSK_VERSION="${DUSK_VERSION}"
 )
 
+if(DUSK_NETWORKING)
+  target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
+    DUSK_NETWORKING
+  )
+endif()
+
 # Toolchains
 include(cmake/targets/${DUSK_TARGET_SYSTEM}.cmake)
 
@@ -116,7 +123,11 @@ if(DUSK_BUILD_TESTS)
 endif()
 
 # Build assets
-file(GLOB_RECURSE DUSK_ASSET_FILES CONFIGURE_DEPENDS "${DUSK_ASSETS_DIR}/*")
+# Deliberately not CONFIGURE_DEPENDS: that reruns the full CMake configure
+# step (which invalidates generated headers and forces a huge rebuild) on
+# every single asset edit. Re-run cmake manually when assets are added or
+# removed.
+file(GLOB_RECURSE DUSK_ASSET_FILES "${DUSK_ASSETS_DIR}/*")
 add_custom_command(
   OUTPUT "${DUSK_ASSETS_ZIP}"
   COMMAND ${CMAKE_COMMAND} -E make_directory "${DUSK_ASSETS_DIR}"

README.md

@@ -1,6 +1,5 @@
-# Documentation
-- [Scripting](docs/SCRIPTING.md) — writing gameplay logic in JavaScript.
-- [UI](docs/UI.md) — building buttons/menus/etc from engine/game C code.
+# Dusk
+RPG Game Project, small and able to run on a PSP.
 
 # Building
 Each build target has different requirements. You can take a look at the git

archive/dusk/ui/CMakeLists.txt

@@ -0,0 +1,18 @@
+# Copyright (c) 2026 Dominic Masters
+# 
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+add_subdirectory(debug)
+add_subdirectory(frame)
+add_subdirectory(focus)
+add_subdirectory(overlay)
+add_subdirectory(transition)
+add_subdirectory(widget)
+
+# Sources
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    ui.c
+    uielement.c
+)

archive/dusk/ui/debug/uiconsole.c

@@ -0,0 +1,138 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uiconsole.h"
+#include "assert/assert.h"
+#include "console/console.h"
+#include "display/screen/screen.h"
+#include "display/text/text.h"
+#include "display/spritebatch/spritebatch.h"
+#include "display/shader/shaderunlit.h"
+#include "display/mesh/mesh.h"
+#include "util/memory.h"
+
+typedef struct {
+  mesh_t mesh;
+  bool_t built;
+  meshvertex_t vertices[UI_CONSOLE_CACHE_VERTEX_MAX];
+  int32_t vertexCount;
+  int32_t cachedScanX;
+  int32_t cachedScanY;
+} uiconsolecache_t;
+
+uiconsolecache_t UI_CONSOLE_CACHE;
+
+errorret_t uiConsoleDraw(void) {
+  if(!CONSOLE.visible) errorOk();
+
+  if(
+    CONSOLE.dirty ||
+    UI_CONSOLE_CACHE.cachedScanX != SCREEN.scanX ||
+    UI_CONSOLE_CACHE.cachedScanY != SCREEN.scanY
+  ) {
+    errorChain(uiConsoleRebuild());
+  }
+
+  if(UI_CONSOLE_CACHE.vertexCount == 0) errorOk();
+
+  shadermaterial_t material = {
+    .unlit = {
+      .color = COLOR_RED,
+      .texture = FONT_DEFAULT.texture
+    }
+  };
+
+  errorChain(shaderBind(&SHADER_UNLIT));
+  errorChain(shaderSetMaterial(&SHADER_UNLIT, &material));
+  return meshDraw(&UI_CONSOLE_CACHE.mesh, 0, UI_CONSOLE_CACHE.vertexCount);
+}
+
+errorret_t uiConsoleRebuild(void) {
+  int32_t spriteCount = 0;
+  for(uint32_t i = 0; i < CONSOLE_HISTORY_MAX; i++) {
+    char_t c;
+    int32_t j = 0;
+    while((c = CONSOLE.line[i][j++]) != '\0') {
+      if(c != ' ' && c != '\n') spriteCount++;
+    }
+  }
+
+  assertTrue(
+    spriteCount <= UI_CONSOLE_CACHE_GLYPH_MAX,
+    "Console history exceeds fixed cache capacity"
+  );
+
+  const int32_t vertexCount = spriteCount * QUAD_VERTEX_COUNT;
+  UI_CONSOLE_CACHE.vertexCount = vertexCount;
+
+  if(vertexCount > 0) {
+    const float_t lineH = (float_t)FONT_DEFAULT.tileset->tileHeight;
+    const float_t charW = (float_t)FONT_DEFAULT.tileset->tileWidth;
+
+    int32_t index = 0;
+    int32_t row = 0;
+    for(uint32_t i = 0; i < CONSOLE_HISTORY_MAX; i++) {
+      float_t posX = (float_t)SCREEN.scanX;
+      float_t posY = (float_t)SCREEN.scanY + lineH * (float_t)row;
+
+      char_t c;
+      int32_t j = 0;
+      while((c = CONSOLE.line[i][j++]) != '\0') {
+        if(c == '\n') {
+          posX = (float_t)SCREEN.scanX;
+          posY += lineH;
+          row++;
+          continue;
+        }
+
+        if(c == ' ') {
+          posX += charW;
+          continue;
+        }
+
+        const spritebatchsprite_t sprite = textGetSprite(
+          (vec2){ posX, posY }, c, &FONT_DEFAULT
+        );
+        spriteBatchBufferToMesh(
+          &sprite, 1,
+          &UI_CONSOLE_CACHE.vertices[index], QUAD_VERTEX_COUNT
+        );
+
+        index += QUAD_VERTEX_COUNT;
+        posX += charW;
+      }
+
+      row++;
+    }
+
+    if(!UI_CONSOLE_CACHE.built) {
+      errorChain(meshInit(
+        &UI_CONSOLE_CACHE.mesh,
+        QUAD_PRIMITIVE_TYPE,
+        UI_CONSOLE_CACHE_VERTEX_MAX,
+        UI_CONSOLE_CACHE.vertices
+      ));
+      UI_CONSOLE_CACHE.built = true;
+    } else {
+      errorChain(meshFlush(&UI_CONSOLE_CACHE.mesh, 0, vertexCount));
+    }
+  }
+
+  UI_CONSOLE_CACHE.cachedScanX = SCREEN.scanX;
+  UI_CONSOLE_CACHE.cachedScanY = SCREEN.scanY;
+  CONSOLE.dirty = false;
+  errorOk();
+}
+
+errorret_t uiConsoleDispose(void) {
+  if(UI_CONSOLE_CACHE.built) {
+    errorChain(meshDispose(&UI_CONSOLE_CACHE.mesh));
+  }
+
+  memoryZero(&UI_CONSOLE_CACHE, sizeof(uiconsolecache_t));
+  errorOk();
+}

archive/dusk/ui/debug/uiconsole.h

@@ -0,0 +1,48 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "display/mesh/quad.h"
+
+// Fixed capacity for the console's cached glyph mesh, in glyphs -- the
+// mesh/vertex buffer is sized to this once and never grown/shrunk, so
+// history producing more non-space characters than this asserts (see
+// uiConsoleRebuild) instead of reallocating.
+#define UI_CONSOLE_CACHE_GLYPH_MAX 512
+#define UI_CONSOLE_CACHE_VERTEX_MAX (\
+  UI_CONSOLE_CACHE_GLYPH_MAX * QUAD_VERTEX_COUNT \
+)
+
+/**
+ * Renders the console history into the scan-safe area, drawing a mesh
+ * that is only rebuilt when the history changes or the scan-safe origin
+ * moves, rather than rebuffering vertices every frame. No-ops when the
+ * console is not visible.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiConsoleDraw(void);
+
+/**
+ * Rebuilds the cached mesh for the console's current history and
+ * scan-safe origin. Called automatically by uiConsoleDraw() whenever
+ * needed; only needs calling directly to force an immediate rebuild.
+ * The underlying vertex buffer is a fixed-size array (see
+ * UI_CONSOLE_CACHE_VERTEX_MAX) -- asserts if the history produces more
+ * glyphs than that capacity, rather than growing it.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiConsoleRebuild(void);
+
+/**
+ * Frees the mesh and vertex buffer built up by uiConsoleDraw().
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiConsoleDispose(void);

archive/dusk/ui/debug/uifps.c

@@ -7,13 +7,21 @@
 
 #include "uifps.h"
 #include "time/time.h"
-#include "display/spritebatch/spritebatch.h"
+#include "util/string.h"
 #include "display/text/text.h"
 #include "display/screen/screen.h"
 #include "engine/engine.h"
 
 uifps_t UIFPS;
 
+errorret_t uiFPSInit() {
+  uiLabelInit(&UIFPS.fpsLabel, &FONT_DEFAULT);
+  uiLabelInit(&UIFPS.versionLabel, &FONT_DEFAULT);
+  uiLabelSetText(&UIFPS.versionLabel, ENGINE.version);
+  uiLabelSetColor(&UIFPS.versionLabel, color(255, 255, 255, 128));
+  errorOk();
+}
+
 errorret_t uiFPSDraw() {
   char_t fpsText[32];
 
@@ -50,26 +58,21 @@ errorret_t uiFPSDraw() {
     textColor = COLOR_RED;
   }
 
-  errorChain(textDraw(
-    (float_t)SCREEN.scanX,
-    (float_t)SCREEN.scanY,
-    fpsText, textColor,
-    &FONT_DEFAULT
-  ));
-  errorChain(spriteBatchFlush());
-
-  // ENGINE.version and FONT_DEFAULT never change after boot; measure once.
-  static int32_t versionWidth = -1, versionHeight = 0;
-  if(versionWidth < 0) {
-    textMeasure(ENGINE.version, &FONT_DEFAULT, &versionWidth, &versionHeight);
+  uiLabelSetColor(&UIFPS.fpsLabel, textColor);
+  if(stringCompare(fpsText, UIFPS.fpsLabel.text) != 0) {
+    uiLabelSetText(&UIFPS.fpsLabel, fpsText);
   }
-  errorChain(textDraw(
-    (float_t)(SCREEN.scanX + SCREEN.scanWidth - versionWidth),
-    (float_t)(SCREEN.scanY + SCREEN.scanHeight - versionHeight),
-    ENGINE.version,
-    color(255, 255, 255, 128),
-    &FONT_DEFAULT
+  errorChain(uiLabelDraw(
+    &UIFPS.fpsLabel, (float_t)SCREEN.scanX, (float_t)SCREEN.scanY
   ));
 
-  return spriteBatchFlush();
+  int32_t versionWidth, versionHeight;
+  uiLabelGetSize(&UIFPS.versionLabel, &versionWidth, &versionHeight);
+  errorChain(uiLabelDraw(
+    &UIFPS.versionLabel,
+    (float_t)(SCREEN.scanX + SCREEN.scanWidth - versionWidth),
+    (float_t)(SCREEN.scanY + SCREEN.scanHeight - versionHeight)
+  ));
+
+  errorOk();
 }

archive/dusk/ui/debug/uifps.h

@@ -8,14 +8,24 @@
 #pragma once
 #include "error/error.h"
 #include "time/timeepoch.h"
+#include "ui/widget/uilabel.h"
 
 typedef struct {
   dusktimeepoch_t lastTick;
   float_t fpsAverage;
+  uilabel_t fpsLabel;
+  uilabel_t versionLabel;
 } uifps_t;
 
 extern uifps_t UIFPS;
 
+/**
+ * Initializes the FPS counter, caching the (static) version label.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFPSInit();
+
 /**
  * Draws the FPS counter on the screen, and also does the update (for now).
  *

archive/dusk/ui/focus/uifocus.c

@@ -12,11 +12,11 @@
 #include "time/time.h"
 
 const uifocusdirmap_t UI_FOCUS_DIR_MAP[] = {
-  { INPUT_ACTION_UP,    UI_FOCUS_DIRECTION_UP,     0, -1 },
-  { INPUT_ACTION_DOWN,  UI_FOCUS_DIRECTION_DOWN,   0,  1 },
-  { INPUT_ACTION_LEFT,  UI_FOCUS_DIRECTION_LEFT,  -1,  0 },
-  { INPUT_ACTION_RIGHT, UI_FOCUS_DIRECTION_RIGHT,  1,  0 },
-  { INPUT_ACTION_NULL,  UI_FOCUS_DIRECTION_NONE,   0,  0 },
+  { INPUT_BIND_UP,    UI_FOCUS_DIRECTION_UP,     0, -1 },
+  { INPUT_BIND_DOWN,  UI_FOCUS_DIRECTION_DOWN,   0,  1 },
+  { INPUT_BIND_LEFT,  UI_FOCUS_DIRECTION_LEFT,  -1,  0 },
+  { INPUT_BIND_RIGHT, UI_FOCUS_DIRECTION_RIGHT,  1,  0 },
+  { INPUT_BIND_NULL,  UI_FOCUS_DIRECTION_NONE,   0,  0 },
 };
 
 uifocus_t UI_FOCUS;
@@ -108,7 +108,7 @@ void uiFocusMoveDirection(
 ) {
   for(
     const uifocusdirmap_t *m = UI_FOCUS_DIR_MAP;
-    m->action != INPUT_ACTION_NULL;
+    m->action != INPUT_BIND_NULL;
     m++
   ) {
     if(m->direction != dir) continue;
@@ -142,19 +142,19 @@ void uiFocusUpdate(void) {
 
   uifocusitem_t *item = &UI_FOCUS.items[UI_FOCUS.count - 1];
 
-  if(inputPressed(INPUT_ACTION_ACCEPT)) {
+  if(inputPressed(INPUT_BIND_ACCEPT)) {
     if(item->selected != NULL) item->selected(item);
     return;
   }
 
-  if(inputPressed(INPUT_ACTION_CANCEL)) {
+  if(inputPressed(INPUT_BIND_CANCEL)) {
     uiFocusPop();
     return;
   }
 
   for(
     const uifocusdirmap_t *m = UI_FOCUS_DIR_MAP;
-    m->action != INPUT_ACTION_NULL;
+    m->action != INPUT_BIND_NULL;
     m++
   ) {
     if(!inputPressed(m->action)) continue;
@@ -167,7 +167,7 @@ void uiFocusUpdate(void) {
   bool_t held = false;
   for(
     const uifocusdirmap_t *m = UI_FOCUS_DIR_MAP;
-    m->action != INPUT_ACTION_NULL;
+    m->action != INPUT_BIND_NULL;
     m++
   ) {
     if(m->direction != UI_FOCUS.direction) continue;

archive/dusk/ui/focus/uifocus.h

@@ -23,7 +23,7 @@
 #define UI_FOCUS_HOLD_REPEAT 0.1f
 
 typedef struct {
-  inputaction_t action;
+  inputbind_t action;
   uifocusdirection_t direction;
   int8_t dx;
   int8_t dy;
@@ -31,7 +31,7 @@ typedef struct {
 
 /**
  * Mapping of input actions to focus directions, terminated by an
- * entry with action == INPUT_ACTION_NULL.
+ * entry with action == INPUT_BIND_NULL.
  */
 extern const uifocusdirmap_t UI_FOCUS_DIR_MAP[];
 

archive/dusk/ui/frame/CMakeLists.txt

@@ -0,0 +1,12 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    uiframe.c
+    uiconfirm.c
+)
+
+add_subdirectory(settings)

archive/dusk/ui/frame/settings/CMakeLists.txt

@@ -0,0 +1,13 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    uisettings.c
+    uisettingsgeneral.c
+    uisettingsinput.c
+    uisettingsdisplay.c
+    uisettingsaudio.c
+)

archive/dusk/ui/frame/settings/uisettings.c

@@ -0,0 +1,248 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uisettings.h"
+#include "uisettingsgeneral.h"
+#include "uisettingsinput.h"
+#include "uisettingsdisplay.h"
+#include "uisettingsaudio.h"
+#include "ui/frame/uiframe.h"
+#include "ui/frame/uiconfirm.h"
+#include "util/memory.h"
+#include "display/text/text.h"
+#include "display/screen/screen.h"
+#include "assert/assert.h"
+#include "locale/localemanager.h"
+#include "asset/loader/locale/assetlocaleloader.h"
+
+uisettings_t UI_SETTINGS;
+
+uisettingstabdef_t UI_SETTINGS_TAB_DEFS[UI_SETTINGS_TAB_COUNT] = {
+  {
+    .localeId = "ui.settings.tabs.general",
+    .init = uiSettingsGeneralInit,
+    .menu = (uimenu_t *)&UI_SETTINGS.data,
+    .load = uiSettingsGeneralLoad,
+    .apply = uiSettingsGeneralApply,
+    .hasChanges = uiSettingsGeneralHasChanges
+  },
+
+  {
+    .localeId = "ui.settings.tabs.input",
+    .init = uiSettingsInputInit,
+    .menu = (uimenu_t *)&UI_SETTINGS.data,
+    .load = uiSettingsInputLoad,
+    .apply = uiSettingsInputApply,
+    .hasChanges = uiSettingsInputHasChanges
+  },
+
+  {
+    .localeId = "ui.settings.tabs.display",
+    .init = uiSettingsDisplayInit,
+    .menu = (uimenu_t *)&UI_SETTINGS.data,
+    .load = uiSettingsDisplayLoad,
+    .apply = uiSettingsDisplayApply,
+    .hasChanges = uiSettingsDisplayHasChanges
+  },
+
+  {
+    .localeId = "ui.settings.tabs.audio",
+    .init = uiSettingsAudioInit,
+    .menu = (uimenu_t *)&UI_SETTINGS.data,
+    .load = uiSettingsAudioLoad,
+    .apply = uiSettingsAudioApply,
+    .hasChanges = uiSettingsAudioHasChanges
+  }
+};
+
+static uisettingstabdef_t UI_SETTINGS_TOP_DEF = {
+  .menu = &UI_SETTINGS.tabsMenu,
+  .load = uiSettingsLoad,
+  .hasChanges = uiSettingsHasChanges
+};
+
+static uisettingstabdef_t *UI_SETTINGS_PENDING_DISCARD = NULL;
+static uisettingstabdef_t *UI_SETTINGS_ACTIVE_TAB = NULL;
+
+errorret_t uiSettingsActivateTab(uisettingstabdef_t *def) {
+  if(def == UI_SETTINGS_ACTIVE_TAB) errorOk();
+
+  errorChain(def->init(&UI_SETTINGS.data));
+  def->menu->user = def;
+  def->load();
+  UI_SETTINGS_ACTIVE_TAB = def;
+
+  errorOk();
+}
+
+void uiSettingsTabChanged(
+  const uimenu_t *menu,
+  const uint8_t index,
+  const uimenuitem_t *item
+) {
+  if(index >= UI_SETTINGS_TAB_COUNT) return;
+  errorCatch(uiSettingsActivateTab(&UI_SETTINGS_TAB_DEFS[index]));
+}
+
+void uiSettingsTabSelected(
+  const uimenu_t *menu,
+  const uint8_t index,
+  const uimenuitem_t *item
+) {
+  if(index >= UI_SETTINGS_TAB_COUNT) return;
+
+  uisettingstabdef_t *def = &UI_SETTINGS_TAB_DEFS[index];
+  errorCatch(uiSettingsActivateTab(def));
+  uiMenuOpen(def->menu);
+}
+
+errorret_t uiSettingsInit(void) {
+  memoryZero(&UI_SETTINGS, sizeof(uisettings_t));
+  UI_SETTINGS_ACTIVE_TAB = NULL;
+
+  for(uint8_t i = 0; i < UI_SETTINGS_TAB_COUNT; i++) {
+    errorChain(assetLocaleGetString(
+      &LOCALE.entry->data.locale,
+      UI_SETTINGS_TAB_DEFS[i].localeId,
+      0,
+      UI_SETTINGS.tabLabels[i],
+      UI_SETTINGS_TAB_LABEL_MAX
+    ));
+  }
+
+  MENU_BEGIN(
+    &UI_SETTINGS.tabsMenu, UI_SETTINGS.tabs, uiSettingsTabSelected,
+    uiSettingsDiscardMenuClosed, uiSettingsTabChanged
+  );
+  for(uint8_t i = 0; i < UI_SETTINGS_TAB_COUNT; i++) {
+    MENU_TAB(UI_SETTINGS.tabLabels[i]);
+  }
+  MENU_END(UI_SETTINGS.tabs, menuIndex);
+
+  UI_SETTINGS.tabsMenu.user = &UI_SETTINGS_TOP_DEF;
+
+  errorChain(assetLocaleGetString(
+    &LOCALE.entry->data.locale,
+    "ui.settings.apply",
+    0,
+    UI_SETTINGS.applyLabel,
+    UI_SETTINGS_APPLY_LABEL_MAX
+  ));
+
+  errorChain(uiSettingsActivateTab(&UI_SETTINGS_TAB_DEFS[0]));
+
+  errorOk();
+}
+
+errorret_t uiSettingsDraw(void) {
+  if(!uiMenuIsActive(&UI_SETTINGS.tabsMenu)) errorOk();
+
+  const float_t width = SCREEN.width;
+  const float_t height = SCREEN.height;
+  const float_t x = (float_t)SCREEN.scanX +
+    ((float_t)SCREEN.scanWidth - width) * 0.5f;
+  const float_t y = (float_t)SCREEN.scanY +
+    ((float_t)SCREEN.scanHeight - height) * 0.5f;
+
+  errorChain(uiFrameDrawCached(&UI_SETTINGS.frameCache, x, y, width, height));
+
+  const float_t contentX = x + UI_FRAME_START_X;
+  const float_t contentY = y + UI_FRAME_START_Y;
+  const float_t contentWidth = width - (UI_FRAME_START_X * 2);
+  const float_t contentHeight = height - (UI_FRAME_START_Y * 2);
+
+  errorChain(uiMenuDraw(
+    &UI_SETTINGS.tabsMenu,
+    contentX,
+    contentY,
+    contentWidth,
+    contentHeight
+  ));
+
+  const float_t tabsRowHeight = (float_t)FONT_DEFAULT.tileset->tileHeight;
+  const float_t pageY = contentY + tabsRowHeight + UI_FRAME_PADDING_Y;
+  const float_t pageHeight = contentHeight - tabsRowHeight - UI_FRAME_PADDING_Y;
+
+  if(UI_SETTINGS_ACTIVE_TAB != NULL) {
+    errorChain(uiMenuDraw(
+      UI_SETTINGS_ACTIVE_TAB->menu, contentX, pageY, contentWidth, pageHeight
+    ));
+  }
+
+  errorOk();
+}
+
+errorret_t uiSettingsUpdate(void) {
+  if(!UI_SETTINGS_PENDING_DISCARD) errorOk();
+
+  uisettingstabdef_t *def = UI_SETTINGS_PENDING_DISCARD;
+  UI_SETTINGS_PENDING_DISCARD = NULL;
+
+  return uiSettingsDiscardUpdate(def);
+}
+
+bool_t uiSettingsIsOpen(void) {
+  return uiMenuIsActive(&UI_SETTINGS.tabsMenu);
+}
+
+void uiSettingsOpen() {
+  uiSettingsLoad();
+  uiMenuOpen(&UI_SETTINGS.tabsMenu);
+}
+
+void uiSettingsClose() {
+  uiMenuClose(&UI_SETTINGS.tabsMenu);
+}
+
+errorret_t uiSettingsDispose(void) {
+  errorOk();
+}
+
+void uiSettingsLoad(void) {
+  if(UI_SETTINGS_ACTIVE_TAB != NULL) UI_SETTINGS_ACTIVE_TAB->load();
+}
+
+void uiSettingsApply(void) {
+  if(UI_SETTINGS_ACTIVE_TAB != NULL) UI_SETTINGS_ACTIVE_TAB->apply();
+}
+
+bool_t uiSettingsHasChanges(void) {
+  return UI_SETTINGS_ACTIVE_TAB != NULL && UI_SETTINGS_ACTIVE_TAB->hasChanges();
+}
+
+void uiSettingsDiscardMenuClosed(const uimenu_t *menu) {
+  uisettingstabdef_t *def = (uisettingstabdef_t *)menu->user;
+  if(def->hasChanges()) UI_SETTINGS_PENDING_DISCARD = def;
+}
+
+errorret_t uiSettingsDiscardUpdate(uisettingstabdef_t *def) {
+  #define UI_SETTINGS_DISCARD_TEXT_MAX 128
+  char_t text[UI_SETTINGS_DISCARD_TEXT_MAX];
+  errorChain(assetLocaleGetString(
+    &LOCALE.entry->data.locale,
+    "ui.confirm.discard_changes",
+    0,
+    text,
+    UI_SETTINGS_DISCARD_TEXT_MAX
+  ));
+  #undef UI_SETTINGS_DISCARD_TEXT_MAX
+
+  uiConfirmOpen(text, uiSettingsDiscardConfirmResult, def);
+
+  errorOk();
+}
+
+void uiSettingsDiscardConfirmResult(const bool_t result, void *user) {
+  uisettingstabdef_t *def = (uisettingstabdef_t *)user;
+
+  if(!result) {
+    uiMenuOpen(def->menu);
+    return;
+  }
+
+  def->load();
+}

archive/dusk/ui/frame/settings/uisettings.h

@@ -0,0 +1,135 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "ui/widget/uimenu.h"
+#include "ui/frame/uiframe.h"
+#include "uisettingsdata.h"
+
+#define UI_SETTINGS_TAB_COUNT 4
+#define UI_SETTINGS_TAB_LABEL_MAX 32
+#define UI_SETTINGS_APPLY_LABEL_MAX 32
+
+typedef struct {
+  const char_t *localeId;
+  errorret_t (*init)(uisettingsdata_t *data);
+  uimenu_t *menu;
+  void (*load)(void);
+  void (*apply)(void);
+  bool_t (*hasChanges)(void);
+} uisettingstabdef_t;
+
+typedef struct {
+  uimenu_t tabsMenu;
+  uimenuitem_t tabs[UI_SETTINGS_TAB_COUNT];
+  char_t tabLabels[UI_SETTINGS_TAB_COUNT][UI_SETTINGS_TAB_LABEL_MAX];
+  char_t applyLabel[UI_SETTINGS_APPLY_LABEL_MAX];
+  uisettingsdata_t data;
+  uiframecache_t frameCache;
+} uisettings_t;
+
+extern uisettings_t UI_SETTINGS;
+extern uisettingstabdef_t UI_SETTINGS_TAB_DEFS[UI_SETTINGS_TAB_COUNT];
+
+/**
+ * Menu closed callback that flags a pending discard-changes
+ * confirmation if the menu's settings page/panel reports unsaved
+ * changes. Pass this directly as a settings page menu's closed
+ * callback. The pending def is picked up by uiSettingsUpdate on the
+ * next tick.
+ *
+ * @param menu The menu that was just closed.
+ */
+void uiSettingsDiscardMenuClosed(const uimenu_t *menu);
+
+/**
+ * Shows the discard-changes confirmation dialog for def. Called once
+ * by uiSettingsUpdate when uiSettingsDiscardMenuClosed has flagged a
+ * pending def.
+ *
+ * @param def The tab/panel def to show the confirmation for.
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsDiscardUpdate(uisettingstabdef_t *def);
+
+/**
+ * Callback passed to uiConfirmOpen by uiSettingsDiscardUpdate. Reopens
+ * the menu if the user chose to keep editing, otherwise reloads the
+ * widgets back to the actual engine values.
+ *
+ * @param result True if the user confirmed discarding changes, false
+ * to keep editing.
+ * @param user The uisettingstabdef_t* this confirmation belongs to.
+ */
+void uiSettingsDiscardConfirmResult(const bool_t result, void *user);
+
+/**
+ * Initializes the settings panel and all of its category pages.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsInit(void);
+
+/**
+ * Draws the settings panel. No-op when not visible.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsDraw(void);
+
+/**
+ * Updates the settings panel. Shows a discard-changes confirmation if
+ * the panel was just closed with unsaved changes.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsUpdate(void);
+
+/**
+ * Returns true when the settings panel is currently open.
+ *
+ * @returns True if open.
+ */
+bool_t uiSettingsIsOpen(void);
+
+/**
+ * Opens the settings panel. No-op when already open.
+ */
+void uiSettingsOpen();
+
+/**
+ * Closes the settings panel. No-op when already closed.
+ */
+void uiSettingsClose();
+
+/**
+ * Disposes of the settings panel.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsDispose(void);
+
+/**
+ * Loads every category page's widgets from the current engine settings.
+ * Called automatically by uiSettingsOpen.
+ */
+void uiSettingsLoad(void);
+
+/**
+ * Applies every category page's widget values to the engine settings.
+ * Called automatically when a page's own Apply button is pressed.
+ */
+void uiSettingsApply(void);
+
+/**
+ * Returns whether any category page has a widget value that differs
+ * from what was loaded.
+ *
+ * @returns True if there are unsaved changes.
+ */
+bool_t uiSettingsHasChanges(void);

archive/dusk/ui/frame/settings/uisettingsaudio.c

@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uisettingsaudio.h"
+#include "uisettings.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+
+void uiSettingsAudioSelected(
+  const uimenu_t *menu,
+  const uint8_t index,
+  const uimenuitem_t *item
+) {
+  if(index != UI_SETTINGS_AUDIO_INDEX_APPLY) return;
+  uiSettingsAudioApply();
+}
+
+errorret_t uiSettingsAudioInit(uisettingsdata_t *data) {
+  uisettingsaudio_t *audio = &data->audio;
+  memoryZero(audio, sizeof(uisettingsaudio_t));
+
+  MENU_BEGIN(
+    &audio->menu, audio->items,
+    uiSettingsAudioSelected, uiSettingsDiscardMenuClosed, NULL
+  );
+  MENU_LABEL("No audio settings yet");
+  MENU_BUTTON(UI_SETTINGS.applyLabel);
+
+  MENU_END(audio->items, 1);
+
+  errorOk();
+}
+
+void uiSettingsAudioLoad(void) {
+}
+
+void uiSettingsAudioApply(void) {
+  uiMenuClose(&UI_SETTINGS.data.audio.menu);
+}
+
+bool_t uiSettingsAudioHasChanges(void) {
+  return false;
+}

archive/dusk/ui/frame/settings/uisettingsaudio.h

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "uisettingsdata.h"
+
+/**
+ * Initializes the audio settings page into the shared settings data
+ * union.
+ *
+ * @param data The shared settings data union to initialize into.
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsAudioInit(uisettingsdata_t *data);
+
+/**
+ * Loads the page's widgets from the current engine audio settings.
+ */
+void uiSettingsAudioLoad(void);
+
+/**
+ * Applies the page's widget values to the engine audio settings.
+ */
+void uiSettingsAudioApply(void);
+
+/**
+ * Returns whether any widget's value differs from what was loaded.
+ *
+ * @returns True if there are unsaved changes.
+ */
+bool_t uiSettingsAudioHasChanges(void);

archive/dusk/ui/frame/settings/uisettingsdata.h

@@ -0,0 +1,67 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "ui/widget/uimenu.h"
+
+#define UI_SETTINGS_GENERAL_ITEM_COUNT 3
+#define UI_SETTINGS_GENERAL_INDEX_LANGUAGE 0
+#define UI_SETTINGS_GENERAL_INDEX_LANGUAGE_DETAIL 1
+#define UI_SETTINGS_GENERAL_INDEX_APPLY 2
+#define UI_SETTINGS_GENERAL_LOCALE_COUNT 3
+#define UI_SETTINGS_GENERAL_LABEL_MAX 32
+#define UI_SETTINGS_GENERAL_INFO_MAX 64
+
+typedef struct {
+  uimenu_t menu;
+  uimenuitem_t items[UI_SETTINGS_GENERAL_ITEM_COUNT];
+  const char_t *localeNames[UI_SETTINGS_GENERAL_LOCALE_COUNT];
+  char_t languageLabel[UI_SETTINGS_GENERAL_LABEL_MAX];
+  char_t labelInfo[UI_SETTINGS_GENERAL_INFO_MAX];
+} uisettingsgeneral_t;
+
+#define UI_SETTINGS_INPUT_ITEM_COUNT 2
+#define UI_SETTINGS_INPUT_LABEL_MAX 32
+#define UI_SETTINGS_INPUT_INDEX_DEADZONE 0
+#define UI_SETTINGS_INPUT_INDEX_APPLY 1
+
+typedef struct {
+  uimenu_t menu;
+  uimenuitem_t items[UI_SETTINGS_INPUT_ITEM_COUNT];
+  char_t deadzoneLabel[UI_SETTINGS_INPUT_LABEL_MAX];
+} uisettingsinput_t;
+
+#define UI_SETTINGS_DISPLAY_ITEM_COUNT 2
+#define UI_SETTINGS_DISPLAY_INDEX_APPLY 1
+
+typedef struct {
+  uimenu_t menu;
+  uimenuitem_t items[UI_SETTINGS_DISPLAY_ITEM_COUNT];
+} uisettingsdisplay_t;
+
+#define UI_SETTINGS_AUDIO_ITEM_COUNT 2
+#define UI_SETTINGS_AUDIO_INDEX_APPLY 1
+
+typedef struct {
+  uimenu_t menu;
+  uimenuitem_t items[UI_SETTINGS_AUDIO_ITEM_COUNT];
+} uisettingsaudio_t;
+
+/**
+ * Shared, overlapping storage for every settings tab's page data. Only
+ * one member is ever live at a time -- the active tab's Init writes
+ * into it, overwriting whatever the previously active tab left there.
+ * This trades simultaneous access to every tab for a memory footprint
+ * of only the single largest page.
+ */
+typedef union {
+  uisettingsgeneral_t general;
+  uisettingsinput_t input;
+  uisettingsdisplay_t display;
+  uisettingsaudio_t audio;
+} uisettingsdata_t;

archive/dusk/ui/frame/settings/uisettingsdisplay.c

@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uisettingsdisplay.h"
+#include "uisettings.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+
+void uiSettingsDisplaySelected(
+  const uimenu_t *menu,
+  const uint8_t index,
+  const uimenuitem_t *item
+) {
+  if(index != UI_SETTINGS_DISPLAY_INDEX_APPLY) return;
+  uiSettingsDisplayApply();
+}
+
+errorret_t uiSettingsDisplayInit(uisettingsdata_t *data) {
+  uisettingsdisplay_t *display = &data->display;
+  memoryZero(display, sizeof(uisettingsdisplay_t));
+
+  MENU_BEGIN(
+    &display->menu, display->items,
+    uiSettingsDisplaySelected, uiSettingsDiscardMenuClosed, NULL
+  );
+  MENU_LABEL("No display settings yet");
+  MENU_BUTTON(UI_SETTINGS.applyLabel);
+
+  MENU_END(display->items, 1);
+
+  errorOk();
+}
+
+void uiSettingsDisplayLoad(void) {
+}
+
+void uiSettingsDisplayApply(void) {
+  uiMenuClose(&UI_SETTINGS.data.display.menu);
+}
+
+bool_t uiSettingsDisplayHasChanges(void) {
+  return false;
+}

archive/dusk/ui/frame/settings/uisettingsdisplay.h

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "uisettingsdata.h"
+
+/**
+ * Initializes the display settings page into the shared settings data
+ * union.
+ *
+ * @param data The shared settings data union to initialize into.
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsDisplayInit(uisettingsdata_t *data);
+
+/**
+ * Loads the page's widgets from the current engine display settings.
+ */
+void uiSettingsDisplayLoad(void);
+
+/**
+ * Applies the page's widget values to the engine display settings.
+ */
+void uiSettingsDisplayApply(void);
+
+/**
+ * Returns whether any widget's value differs from what was loaded.
+ *
+ * @returns True if there are unsaved changes.
+ */
+bool_t uiSettingsDisplayHasChanges(void);

archive/dusk/ui/frame/settings/uisettingsgeneral.c

@@ -0,0 +1,117 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uisettingsgeneral.h"
+#include "uisettings.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "util/string.h"
+#include "locale/localemanager.h"
+#include "locale/localeinfo.h"
+#include "asset/loader/locale/assetlocaleloader.h"
+
+static const localeinfo_t *const UI_SETTINGS_GENERAL_LOCALES[
+  UI_SETTINGS_GENERAL_LOCALE_COUNT
+] = {
+  &LOCALE_EN_US,
+  &LOCALE_JP_JP,
+  &LOCALE_ES_MX
+};
+
+void uiSettingsGeneralSelected(
+  const uimenu_t *menu,
+  const uint8_t index,
+  const uimenuitem_t *item
+) {
+  switch(index) {
+    case UI_SETTINGS_GENERAL_INDEX_APPLY:
+      uiSettingsGeneralApply();
+      break;
+
+    default:
+      break;
+  }
+}
+
+errorret_t uiSettingsGeneralInit(uisettingsdata_t *data) {
+  uisettingsgeneral_t *general = &data->general;
+  memoryZero(general, sizeof(uisettingsgeneral_t));
+
+  for(uint8_t i = 0; i < UI_SETTINGS_GENERAL_LOCALE_COUNT; i++) {
+    general->localeNames[i] = UI_SETTINGS_GENERAL_LOCALES[i]->name;
+  }
+
+  errorChain(assetLocaleGetString(
+    &LOCALE.entry->data.locale,
+    "ui.settings.general.language",
+    0,
+    general->languageLabel,
+    UI_SETTINGS_GENERAL_LABEL_MAX
+  ));
+  errorChain(assetLocaleGetString(
+    &LOCALE.entry->data.locale,
+    "ui.settings.general.language_detail",
+    0,
+    general->labelInfo,
+    UI_SETTINGS_GENERAL_INFO_MAX
+  ));
+
+  MENU_BEGIN(
+    &general->menu, general->items,
+    uiSettingsGeneralSelected, uiSettingsDiscardMenuClosed, NULL
+  );
+
+  MENU_DROPDOWN(
+    general->languageLabel, general->localeNames,
+    UI_SETTINGS_GENERAL_LOCALE_COUNT, 0
+  );
+  MENU_LABEL(general->labelInfo);
+
+  MENU_BUTTON(UI_SETTINGS.applyLabel);
+  MENU_END(general->items, 1);
+
+  errorOk();
+}
+
+void uiSettingsGeneralLoad(void) {
+  uisettingsgeneral_t *general = &UI_SETTINGS.data.general;
+
+  uint8_t index = 0;
+  for(uint8_t i = 0; i < UI_SETTINGS_GENERAL_LOCALE_COUNT; i++) {
+    if(stringCompare(LOCALE.locale->file, UI_SETTINGS_GENERAL_LOCALES[i]->file) != 0) {
+      continue;
+    }
+    index = i;
+    break;
+  }
+
+  uiDropdownSetSelectedIndex(
+    &general->items[UI_SETTINGS_GENERAL_INDEX_LANGUAGE].dropdown, index
+  );
+}
+
+void uiSettingsGeneralApply(void) {
+  uisettingsgeneral_t *general = &UI_SETTINGS.data.general;
+
+  uint8_t index = uiDropdownGetSelectedIndex(
+    &general->items[UI_SETTINGS_GENERAL_INDEX_LANGUAGE].dropdown
+  );
+  errorCatch(localeManagerSetLocale(UI_SETTINGS_GENERAL_LOCALES[index]));
+
+  uiMenuClose(&general->menu);
+}
+
+bool_t uiSettingsGeneralHasChanges(void) {
+  uisettingsgeneral_t *general = &UI_SETTINGS.data.general;
+
+  uint8_t index = uiDropdownGetSelectedIndex(
+    &general->items[UI_SETTINGS_GENERAL_INDEX_LANGUAGE].dropdown
+  );
+  return stringCompare(
+    LOCALE.locale->file, UI_SETTINGS_GENERAL_LOCALES[index]->file
+  ) != 0;
+}

archive/dusk/ui/frame/settings/uisettingsgeneral.h

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "uisettingsdata.h"
+
+/**
+ * Initializes the general settings page into the shared settings data
+ * union.
+ *
+ * @param data The shared settings data union to initialize into.
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsGeneralInit(uisettingsdata_t *data);
+
+/**
+ * Loads the page's widgets from the current engine general settings.
+ */
+void uiSettingsGeneralLoad(void);
+
+/**
+ * Applies the page's widget values to the engine general settings.
+ */
+void uiSettingsGeneralApply(void);
+
+/**
+ * Returns whether any widget's value differs from what was loaded.
+ *
+ * @returns True if there are unsaved changes.
+ */
+bool_t uiSettingsGeneralHasChanges(void);

archive/dusk/ui/frame/settings/uisettingsinput.c

@@ -0,0 +1,82 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uisettingsinput.h"
+#include "uisettings.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "locale/localemanager.h"
+#include "asset/loader/locale/assetlocaleloader.h"
+#include "input/input.h"
+#include "save/savesettings.h"
+
+void uiSettingsInputSelected(
+  const uimenu_t *menu,
+  const uint8_t index,
+  const uimenuitem_t *item
+) {
+  if(index != UI_SETTINGS_INPUT_INDEX_APPLY) return;
+  uiSettingsInputApply();
+}
+
+errorret_t uiSettingsInputInit(uisettingsdata_t *data) {
+  uisettingsinput_t *input = &data->input;
+  memoryZero(input, sizeof(uisettingsinput_t));
+
+  MENU_BEGIN(
+    &input->menu, input->items,
+    uiSettingsInputSelected, uiSettingsDiscardMenuClosed, NULL
+  );
+  #ifdef DUSK_INPUT_GAMEPAD
+    errorChain(assetLocaleGetString(
+      &LOCALE.entry->data.locale,
+      "ui.settings.input.deadzone",
+      0,
+      input->deadzoneLabel,
+      UI_SETTINGS_INPUT_LABEL_MAX
+    ));
+    MENU_SLIDER_FLOAT(
+      input->deadzoneLabel, INPUT_DEADZONE_DEFAULT, 0.0f, 1.0f, 0.05f
+    );
+  #else
+    MENU_LABEL("No input settings yet");
+  #endif
+
+  MENU_BUTTON(UI_SETTINGS.applyLabel);
+  MENU_END(input->items, 1);
+
+  errorOk();
+}
+
+void uiSettingsInputLoad(void) {
+  #ifdef DUSK_INPUT_GAMEPAD
+    uiSliderSetFloat(
+      &UI_SETTINGS.data.input.items[UI_SETTINGS_INPUT_INDEX_DEADZONE].slider,
+      INPUT.deadzone
+    );
+  #endif
+}
+
+void uiSettingsInputApply(void) {
+  #ifdef DUSK_INPUT_GAMEPAD
+    INPUT.deadzone = uiSliderGetFloat(
+      &UI_SETTINGS.data.input.items[UI_SETTINGS_INPUT_INDEX_DEADZONE].slider
+    );
+  #endif
+  errorCatch(errorPrint(saveSettingsWrite()));
+  uiMenuClose(&UI_SETTINGS.data.input.menu);
+}
+
+bool_t uiSettingsInputHasChanges(void) {
+  #ifdef DUSK_INPUT_GAMEPAD
+    if(uiSliderGetFloat(
+      &UI_SETTINGS.data.input.items[UI_SETTINGS_INPUT_INDEX_DEADZONE].slider
+    ) != INPUT.deadzone) return true;
+  #endif
+
+  return false;
+}

archive/dusk/ui/frame/settings/uisettingsinput.h

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "uisettingsdata.h"
+
+/**
+ * Initializes the input settings page into the shared settings data
+ * union.
+ *
+ * @param data The shared settings data union to initialize into.
+ * @return Any error that occurs.
+ */
+errorret_t uiSettingsInputInit(uisettingsdata_t *data);
+
+/**
+ * Loads the page's widgets from the current engine input settings.
+ */
+void uiSettingsInputLoad(void);
+
+/**
+ * Applies the page's widget values to the engine input settings.
+ */
+void uiSettingsInputApply(void);
+
+/**
+ * Returns whether any widget's value differs from what was loaded.
+ *
+ * @returns True if there are unsaved changes.
+ */
+bool_t uiSettingsInputHasChanges(void);

archive/dusk/ui/frame/uiconfirm.c

@@ -0,0 +1,126 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uiconfirm.h"
+#include "uiframe.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "util/math.h"
+#include "display/screen/screen.h"
+#include "display/text/text.h"
+#include "display/color.h"
+#include "display/spritebatch/spritebatch.h"
+#include "display/texture/texture.h"
+#include "display/shader/shaderunlit.h"
+
+#define UI_CONFIRM_BACKDROP_COLOR color4b(0, 0, 0, 160)
+
+uiconfirm_t UI_CONFIRM;
+
+void uiConfirmSelected(
+  const uimenu_t *menu,
+  const uint8_t index,
+  const uimenuitem_t *item
+) {
+  UI_CONFIRM.result = index == UI_CONFIRM_INDEX_CONFIRM;
+  uiConfirmClose();
+}
+
+void uiConfirmClosed(const uimenu_t *menu) {
+  if(UI_CONFIRM.callback != NULL) {
+    UI_CONFIRM.callback(UI_CONFIRM.result, UI_CONFIRM.user);
+  }
+}
+
+errorret_t uiConfirmInit(void) {
+  memoryZero(&UI_CONFIRM, sizeof(uiconfirm_t));
+  uiLabelInit(&UI_CONFIRM.textLabel, &FONT_DEFAULT);
+
+  MENU_BEGIN(
+    &UI_CONFIRM.menu, UI_CONFIRM.items, uiConfirmSelected, uiConfirmClosed, NULL
+  );
+  MENU_BUTTON("Confirm");
+  MENU_BUTTON("Cancel");
+
+  MENU_END(UI_CONFIRM.items, menuIndex);
+
+  errorOk();
+}
+
+errorret_t uiConfirmDraw(void) {
+  if(!uiMenuIsActive(&UI_CONFIRM.menu)) errorOk();
+
+  spritebatchsprite_t backdropSprite = {
+    .min = { 0.0f, 0.0f, 0.0f },
+    .max = { (float_t)SCREEN.width, (float_t)SCREEN.height, 0.0f },
+    .uvMin = { 0.0f, 0.0f },
+    .uvMax = { 1.0f, 1.0f }
+  };
+  shadermaterial_t backdropMaterial = {
+    .unlit = {
+      .color = UI_CONFIRM_BACKDROP_COLOR,
+      .texture = &TEXTURE_WHITE
+    }
+  };
+  errorChain(
+    spriteBatchBuffer(&backdropSprite, 1, &SHADER_UNLIT, backdropMaterial)
+  );
+
+  int32_t textW, textH;
+  uiLabelGetSize(&UI_CONFIRM.textLabel, &textW, &textH);
+
+  float_t rowHeight = (float_t)FONT_DEFAULT.tileset->tileHeight;
+  float_t width = mathMax(
+    (float_t)textW + (UI_FRAME_START_X * 2), UI_CONFIRM_MIN_WIDTH
+  );
+  float_t height = (UI_FRAME_START_Y * 2) + rowHeight + UI_FRAME_PADDING_Y +
+    rowHeight;
+  float_t x = (float_t)SCREEN.scanX + ((float_t)SCREEN.scanWidth - width) * 0.5f;
+  float_t y = (float_t)SCREEN.scanY + ((float_t)SCREEN.scanHeight - height) * 0.5f;
+
+  errorChain(uiFrameDrawCached(&UI_CONFIRM.frameCache, x, y, width, height));
+
+  float_t contentX = x + UI_FRAME_START_X;
+  float_t contentY = y + UI_FRAME_START_Y;
+  float_t contentWidth = width - (UI_FRAME_START_X * 2);
+
+  errorChain(uiLabelDraw(&UI_CONFIRM.textLabel, contentX, contentY));
+
+  float_t buttonsY = contentY + rowHeight + UI_FRAME_PADDING_Y;
+  errorChain(uiMenuDraw(&UI_CONFIRM.menu, contentX, buttonsY, contentWidth, rowHeight));
+
+  errorOk();
+}
+
+bool_t uiConfirmIsOpen(void) {
+  return uiMenuIsActive(&UI_CONFIRM.menu);
+}
+
+bool_t uiConfirmGetResult(void) {
+  return UI_CONFIRM.result;
+}
+
+void uiConfirmOpen(
+  const char_t *question,
+  uiconfirmcallback_t callback,
+  void *user
+) {
+  assertNotNull(question, "Question cannot be NULL");
+  uiLabelSetText(&UI_CONFIRM.textLabel, question);
+  UI_CONFIRM.callback = callback;
+  UI_CONFIRM.user = user;
+  UI_CONFIRM.result = false;
+  uiMenuOpen(&UI_CONFIRM.menu);
+}
+
+void uiConfirmClose(void) {
+  uiMenuClose(&UI_CONFIRM.menu);
+}
+
+errorret_t uiConfirmDispose(void) {
+  errorOk();
+}

archive/dusk/ui/frame/uiconfirm.h

@@ -0,0 +1,96 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "ui/widget/uimenu.h"
+#include "ui/widget/uilabel.h"
+#include "ui/frame/uiframe.h"
+
+#define UI_CONFIRM_MIN_WIDTH 160.0f
+#define UI_CONFIRM_INDEX_CONFIRM 0
+#define UI_CONFIRM_INDEX_CANCEL 1
+#define UI_CONFIRM_ITEM_COUNT 2
+
+/**
+ * Callback invoked once a confirm dialog is dismissed.
+ *
+ * @param result True if Confirm was selected, false if Cancel was
+ * selected or the dialog was backed out of.
+ * @param user Arbitrary pointer passed to uiConfirmOpen.
+ */
+typedef void (*uiconfirmcallback_t)(const bool_t result, void *user);
+
+typedef struct {
+  uilabel_t textLabel;
+  uimenu_t menu;
+  uimenuitem_t items[UI_CONFIRM_ITEM_COUNT];
+  uiconfirmcallback_t callback;
+  void *user;
+  bool_t result;
+  uiframecache_t frameCache;
+} uiconfirm_t;
+
+extern uiconfirm_t UI_CONFIRM;
+
+/**
+ * Initializes the confirm dialog.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiConfirmInit(void);
+
+/**
+ * Draws the confirm dialog: a semi-transparent black backdrop covering
+ * the whole screen, then its own centered frame with the question text
+ * and Confirm/Cancel buttons. No-op when not open.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiConfirmDraw(void);
+
+/**
+ * Returns true when the confirm dialog is currently open.
+ *
+ * @returns True if open.
+ */
+bool_t uiConfirmIsOpen(void);
+
+/**
+ * Returns the result of the most recently dismissed confirm dialog.
+ *
+ * @returns True if Confirm was selected, false otherwise.
+ */
+bool_t uiConfirmGetResult(void);
+
+/**
+ * Opens the confirm dialog with the given question text. callback is
+ * invoked exactly once with the result, whether the dialog was
+ * dismissed by selecting a button or by pressing cancel/back.
+ *
+ * @param question Display text; copied internally, safe to be transient.
+ * @param callback Called with the result once the dialog closes. May be
+ * NULL.
+ * @param user Arbitrary pointer passed through to callback.
+ */
+void uiConfirmOpen(
+  const char_t *question,
+  uiconfirmcallback_t callback,
+  void *user
+);
+
+/**
+ * Closes the confirm dialog. No-op when already closed.
+ */
+void uiConfirmClose(void);
+
+/**
+ * Disposes of the confirm dialog.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiConfirmDispose(void);

archive/dusk/ui/frame/uiframe.c

@@ -0,0 +1,161 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uiframe.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "display/texture/texture.h"
+#include "display/spritebatch/spritebatch.h"
+#include "display/shader/shaderunlit.h"
+#include "display/color.h"
+
+uiframe_t UI_FRAME;
+
+errorret_t uiFrameInit(void) {
+  memoryZero(&UI_FRAME, sizeof(uiframe_t));
+  
+  // Init texture.
+  color_t border = color4b(0, 50, 255, 255);
+  color_t center = color4b(0, 100, 220, 240);
+
+  for(uint8_t y = 0; y < UI_FRAME_TEXTURE_HEIGHT_POW2; y++) {
+    for(uint8_t x = 0; x < UI_FRAME_TEXTURE_WIDTH_POW2; x++) {
+      color_t c;
+      if(x >= UI_FRAME_TEXTURE_WIDTH || y >= UI_FRAME_TEXTURE_HEIGHT) {
+        c = COLOR_TRANSPARENT;
+      } else if(
+        y < UI_FRAME_TILE_HEIGHT || y >= UI_FRAME_TILE_HEIGHT * 2 ||
+        x < UI_FRAME_TILE_WIDTH  || x >= UI_FRAME_TILE_WIDTH * 2
+      ) {
+        c = border;
+      } else {
+        c = center;
+      }
+      UI_FRAME.pixels[y * UI_FRAME_TEXTURE_WIDTH_POW2 + x] = c;
+    }
+  }
+
+  errorChain(textureInit(
+    &UI_FRAME.texture,
+    UI_FRAME_TEXTURE_WIDTH_POW2, UI_FRAME_TEXTURE_HEIGHT_POW2,
+    TEXTURE_FORMAT_RGBA,
+    (texturedata_t){ .rgbaColors = UI_FRAME.pixels }
+  ));
+
+  UI_FRAME.tileset.tileWidth = UI_FRAME_TILE_WIDTH;
+  UI_FRAME.tileset.tileHeight = UI_FRAME_TILE_HEIGHT;
+  UI_FRAME.tileset.columns = 3;
+  UI_FRAME.tileset.rows = 3;
+  UI_FRAME.tileset.tileCount = 9;
+  UI_FRAME.tileset.uv[0] =
+    (float_t)UI_FRAME_TILE_WIDTH / UI_FRAME_TEXTURE_WIDTH_POW2;
+  UI_FRAME.tileset.uv[1] =
+    (float_t)UI_FRAME_TILE_HEIGHT / UI_FRAME_TEXTURE_HEIGHT_POW2;
+
+  errorOk();
+}
+
+errorret_t uiFrameDraw(
+  const float_t x,
+  const float_t y,
+  const float_t width,
+  const float_t height
+) {
+  shadermaterial_t material = {
+    .unlit = {
+      .color = COLOR_WHITE,
+      .texture = &UI_FRAME.texture
+    }
+  };
+  spritebatchsprite_t sprites[9];
+  uiFrameBuildSprites(sprites, x, y, width, height);
+  return spriteBatchBuffer(sprites, 9, &SHADER_UNLIT, material);
+}
+
+void uiFrameBuildSprites(
+  spritebatchsprite_t sprites[9],
+  const float_t x,
+  const float_t y,
+  const float_t width,
+  const float_t height
+) {
+  float_t tileW = (float_t)UI_FRAME_BORDER_WIDTH;
+  float_t tileH = (float_t)UI_FRAME_BORDER_HEIGHT;
+
+  sprites[0] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 0, 0,
+    x, y, tileW, tileH
+  );
+  sprites[1] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 1, 0,
+    x + tileW, y, width - (tileW * 2.0f), tileH
+  );
+  sprites[2] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 2, 0,
+    x + width - tileW, y, tileW, tileH
+  );
+  sprites[3] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 0, 1,
+    x, y + tileH, tileW, height - (tileH * 2.0f)
+  );
+  sprites[4] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 1, 1,
+    x + tileW, y + tileH,
+    width - (tileW * 2.0f), height - (tileH * 2.0f)
+  );
+  sprites[5] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 2, 1,
+    x + width - tileW, y + tileH, tileW, height - (tileH * 2.0f)
+  );
+  sprites[6] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 0, 2,
+    x, y + height - tileH, tileW, tileH
+  );
+  sprites[7] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 1, 2,
+    x + tileW, y + height - tileH, width - (tileW * 2.0f), tileH
+  );
+  sprites[8] = spriteBatchSpriteTilesetPosition(
+    &UI_FRAME.tileset, 2, 2,
+    x + width - tileW, y + height - tileH, tileW, tileH
+  );
+}
+
+errorret_t uiFrameDrawCached(
+  uiframecache_t *cache,
+  const float_t x,
+  const float_t y,
+  const float_t width,
+  const float_t height
+) {
+  assertNotNull(cache, "Frame cache cannot be NULL");
+
+  if(
+    !cache->built ||
+    cache->lastX != x || cache->lastY != y ||
+    cache->lastWidth != width || cache->lastHeight != height
+  ) {
+    uiFrameBuildSprites(cache->sprites, x, y, width, height);
+    cache->lastX = x;
+    cache->lastY = y;
+    cache->lastWidth = width;
+    cache->lastHeight = height;
+    cache->built = true;
+  }
+
+  shadermaterial_t material = {
+    .unlit = {
+      .color = COLOR_WHITE,
+      .texture = &UI_FRAME.texture
+    }
+  };
+  return spriteBatchBuffer(cache->sprites, 9, &SHADER_UNLIT, material);
+}
+
+errorret_t uiFrameDispose(void) {
+  return textureDispose(&UI_FRAME.texture);
+}

archive/dusk/ui/frame/uiframe.h

@@ -0,0 +1,122 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "display/texture/texture.h"
+#include "display/texture/tileset.h"
+#include "display/spritebatch/spritebatchsprite.h"
+
+#define UI_FRAME_BORDER_WIDTH 6
+#define UI_FRAME_BORDER_HEIGHT 6
+#define UI_FRAME_PADDING_X 2
+#define UI_FRAME_PADDING_Y 2
+#define UI_FRAME_START_X (UI_FRAME_BORDER_WIDTH + UI_FRAME_PADDING_X)
+#define UI_FRAME_START_Y (UI_FRAME_BORDER_HEIGHT + UI_FRAME_PADDING_Y)
+#define UI_FRAME_TILE_WIDTH 1
+#define UI_FRAME_TILE_HEIGHT 1
+#define UI_FRAME_TEXTURE_WIDTH (UI_FRAME_TILE_WIDTH * 3)
+#define UI_FRAME_TEXTURE_HEIGHT (UI_FRAME_TILE_HEIGHT * 3)
+#define UI_FRAME_TEXTURE_WIDTH_POW2 4
+#define UI_FRAME_TEXTURE_HEIGHT_POW2 4 
+
+typedef struct {
+  tileset_t tileset;
+  texture_t texture;
+  color_t pixels[UI_FRAME_BORDER_WIDTH * UI_FRAME_BORDER_HEIGHT];
+} uiframe_t;
+
+extern uiframe_t UI_FRAME;
+
+/**
+ * Initializes the global UI_FRAME: builds the dummy texture and
+ * configures the tileset. Call once after displayInit().
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFrameInit(void);
+
+/**
+ * Draws UI_FRAME using 9-slice rendering from its 3x3 tileset.
+ * Pushes quads to the sprite batch without flushing.
+ *
+ * @param x Screen x position.
+ * @param y Screen y position.
+ * @param width Total width of the frame.
+ * @param height Total height of the frame.
+ * @return Any error that occurs.
+ */
+errorret_t uiFrameDraw(
+  const float_t x,
+  const float_t y,
+  const float_t width,
+  const float_t height
+);
+
+/**
+ * Builds the 9 sprites for a 9-slice frame at the given rect. Used
+ * internally by uiFrameDraw and uiFrameDrawCached -- call directly only
+ * if you need the raw sprites instead of buffering them.
+ *
+ * @param sprites Destination array of exactly 9 sprites.
+ * @param x Screen x position.
+ * @param y Screen y position.
+ * @param width Total width of the frame.
+ * @param height Total height of the frame.
+ */
+void uiFrameBuildSprites(
+  spritebatchsprite_t sprites[9],
+  const float_t x,
+  const float_t y,
+  const float_t width,
+  const float_t height
+);
+
+/**
+ * A frame's cached 9-slice sprites, plus the rect they were built for.
+ * Owned by whichever widget/screen draws a frame repeatedly (dialogs,
+ * textboxes, settings panels) so uiFrameDrawCached can skip rebuilding
+ * the sprites when the rect hasn't moved since the last draw.
+ */
+typedef struct {
+  spritebatchsprite_t sprites[9];
+  bool_t built;
+  float_t lastX;
+  float_t lastY;
+  float_t lastWidth;
+  float_t lastHeight;
+} uiframecache_t;
+
+/**
+ * Draws a 9-slice frame using a caller-owned cache, only rebuilding the
+ * sprites (via uiFrameBuildSprites) when x/y/width/height differ from
+ * the last call -- unlike uiFrameDraw, which rebuilds unconditionally
+ * every time. Prefer this for frames redrawn every frame at a fixed or
+ * rarely-changing rect (dialogs, panels); use plain uiFrameDraw for
+ * genuinely one-off or per-frame-varying rects.
+ *
+ * @param cache Caller-owned cache, zero-initialized before first use.
+ * @param x Screen x position.
+ * @param y Screen y position.
+ * @param width Total width of the frame.
+ * @param height Total height of the frame.
+ * @return Any error that occurs.
+ */
+errorret_t uiFrameDrawCached(
+  uiframecache_t *cache,
+  const float_t x,
+  const float_t y,
+  const float_t width,
+  const float_t height
+);
+
+/**
+ * Disposes of the global UI_FRAME, releasing its GPU texture.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFrameDispose(void);

archive/dusk/ui/overlay/CMakeLists.txt

@@ -0,0 +1,11 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    uicrop.c
+    uifullbox.c
+    uiloading.c
+)

archive/dusk/ui/overlay/uicrop.c

@@ -85,5 +85,5 @@ errorret_t uiCropDraw(void) {
     }
   };
   errorChain(spriteBatchBuffer(sprites, count, &SHADER_UNLIT, material));
-  return spriteBatchFlush();
+  errorOk();
 }

archive/dusk/ui/overlay/uifullbox.c

@@ -0,0 +1,122 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uifullbox.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "time/time.h"
+#include "display/screen/screen.h"
+#include "display/texture/texture.h"
+#include "display/spritebatch/spritebatch.h"
+#include "display/shader/shaderunlit.h"
+
+uifullbox_t UI_FULLBOX_UNDER;
+uifullbox_t UI_FULLBOX_OVER;
+
+void uiFullboxInit(uifullbox_t *fullbox) {
+  assertNotNull(fullbox, "fullbox must not be NULL");
+  memoryZero(fullbox, sizeof(uifullbox_t));
+  eventInit(
+    &fullbox->onTransitionEnd,
+    fullbox->onTransitionEndCallbacks,
+    fullbox->onTransitionEndUsers,
+    4
+  );
+}
+
+void uiFullboxUpdate(uifullbox_t *fullbox, float_t delta) {
+  assertNotNull(fullbox, "fullbox must not be NULL");
+  if(fullbox->duration <= 0.0f || fullbox->time >= fullbox->duration) return;
+
+  fullbox->time += delta;
+  if(fullbox->time >= fullbox->duration) {
+    fullbox->time = fullbox->duration;
+    eventInvoke(&fullbox->onTransitionEnd, fullbox);
+  }
+}
+
+static color_t uiFullboxGetColor(const uifullbox_t *fullbox) {
+  if(fullbox->duration <= 0.0f || fullbox->time >= fullbox->duration) {
+    return fullbox->toColor;
+  }
+  float_t t = easingApply(fullbox->easing, fullbox->time / fullbox->duration);
+  return color4b(
+    (uint8_t)((float_t)fullbox->fromColor.r +
+      ((float_t)fullbox->toColor.r - (float_t)fullbox->fromColor.r) * t),
+    (uint8_t)((float_t)fullbox->fromColor.g +
+      ((float_t)fullbox->toColor.g - (float_t)fullbox->fromColor.g) * t),
+    (uint8_t)((float_t)fullbox->fromColor.b +
+      ((float_t)fullbox->toColor.b - (float_t)fullbox->fromColor.b) * t),
+    (uint8_t)((float_t)fullbox->fromColor.a +
+      ((float_t)fullbox->toColor.a - (float_t)fullbox->fromColor.a) * t)
+  );
+}
+
+errorret_t uiFullboxDraw(uifullbox_t *fullbox) {
+  assertNotNull(fullbox, "fullbox must not be NULL");
+
+  color_t color = uiFullboxGetColor(fullbox);
+  if(color.a == 0) errorOk();
+
+  spritebatchsprite_t sprite = {
+    .min = { 0.0f, 0.0f, 0.0f },
+    .max = { (float_t)SCREEN.width, (float_t)SCREEN.height, 0.0f },
+    .uvMin = { 0.0f, 0.0f },
+    .uvMax = { 1.0f, 1.0f }
+  };
+  shadermaterial_t material = {
+    .unlit = {
+      .color = color,
+      .texture = &TEXTURE_WHITE
+    }
+  };
+  errorChain(spriteBatchBuffer(&sprite, 1, &SHADER_UNLIT, material));
+  errorOk();
+}
+
+void uiFullboxTransition(
+  uifullbox_t *fullbox,
+  color_t from,
+  color_t to,
+  float_t duration,
+  easingtype_t easing
+) {
+  assertNotNull(fullbox, "fullbox must not be NULL");
+  fullbox->fromColor = from;
+  fullbox->toColor = to;
+  fullbox->duration = duration;
+  fullbox->time = 0.0f;
+  fullbox->easing = easing;
+}
+
+errorret_t uiFullboxUnderInit(void) {
+  uiFullboxInit(&UI_FULLBOX_UNDER);
+  errorOk();
+}
+
+errorret_t uiFullboxUnderUpdate(void) {
+  uiFullboxUpdate(&UI_FULLBOX_UNDER, TIME.delta);
+  errorOk();
+}
+
+errorret_t uiFullboxUnderDraw(void) {
+  return uiFullboxDraw(&UI_FULLBOX_UNDER);
+}
+
+errorret_t uiFullboxOverInit(void) {
+  uiFullboxInit(&UI_FULLBOX_OVER);
+  errorOk();
+}
+
+errorret_t uiFullboxOverUpdate(void) {
+  uiFullboxUpdate(&UI_FULLBOX_OVER, TIME.delta);
+  errorOk();
+}
+
+errorret_t uiFullboxOverDraw(void) {
+  return uiFullboxDraw(&UI_FULLBOX_OVER);
+}

archive/dusk/ui/overlay/uifullbox.h

@@ -0,0 +1,109 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "display/color.h"
+#include "animation/easing.h"
+#include "event/event.h"
+
+typedef struct {
+  color_t fromColor;
+  color_t toColor;
+  float_t duration;
+  float_t time;
+  easingtype_t easing;
+  eventcallback_t onTransitionEndCallbacks[4];
+  void *onTransitionEndUsers[4];
+  event_t onTransitionEnd;
+} uifullbox_t;
+
+extern uifullbox_t UI_FULLBOX_UNDER;
+extern uifullbox_t UI_FULLBOX_OVER;
+
+/**
+ * Initializes a fullbox, zeroing all fields.
+ *
+ * @param fullbox The fullbox to initialize.
+ */
+void uiFullboxInit(uifullbox_t *fullbox);
+
+/**
+ * Advances the fullbox transition. Fires onTransitionEnd once when the
+ * transition completes. Safe to call when no transition is running.
+ *
+ * @param fullbox The fullbox to update.
+ * @param delta   Seconds elapsed since last update.
+ */
+void uiFullboxUpdate(uifullbox_t *fullbox, float_t delta);
+
+/**
+ * Renders the fullbox. Skipped entirely when the current alpha is zero.
+ *
+ * @param fullbox The fullbox to draw.
+ * @return Any error that occurs.
+ */
+errorret_t uiFullboxDraw(uifullbox_t *fullbox);
+
+/**
+ * Begins a color transition.
+ *
+ * @param fullbox  The fullbox to transition.
+ * @param from     Start color.
+ * @param to       End color.
+ * @param duration Transition duration in seconds.
+ * @param easing   Easing function to apply.
+ */
+void uiFullboxTransition(
+  uifullbox_t *fullbox,
+  color_t from,
+  color_t to,
+  float_t duration,
+  easingtype_t easing
+);
+
+/**
+ * Init function for UI_FULLBOX_UNDER (registered in UI_ELEMENTS).
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFullboxUnderInit(void);
+
+/**
+ * Update function for UI_FULLBOX_UNDER (registered in UI_ELEMENTS).
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFullboxUnderUpdate(void);
+
+/**
+ * Draw function for UI_FULLBOX_UNDER (registered in UI_ELEMENTS).
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFullboxUnderDraw(void);
+
+/**
+ * Init function for UI_FULLBOX_OVER (registered in UI_ELEMENTS).
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFullboxOverInit(void);
+
+/**
+ * Update function for UI_FULLBOX_OVER (registered in UI_ELEMENTS).
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFullboxOverUpdate(void);
+
+/**
+ * Draw function for UI_FULLBOX_OVER (registered in UI_ELEMENTS).
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiFullboxOverDraw(void);

archive/dusk/ui/overlay/uiloading.c

@@ -0,0 +1,111 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uiloading.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "time/time.h"
+#include "display/text/text.h"
+#include "display/screen/screen.h"
+#include "uifullbox.h"
+
+#define UI_LOADING_TEXT "loading"
+
+uiloading_t UI_LOADING;
+
+errorret_t uiLoadingInit(void) {
+  memoryZero(&UI_LOADING, sizeof(uiloading_t));
+  uiLabelInit(&UI_LOADING.textLabel, &FONT_DEFAULT);
+  uiLabelSetText(&UI_LOADING.textLabel, UI_LOADING_TEXT);
+  eventInit(
+    &UI_LOADING.onTransitionEnd,
+    UI_LOADING.onTransitionEndCallbacks,
+    UI_LOADING.onTransitionEndUsers,
+    4
+  );
+  errorOk();
+}
+
+errorret_t uiLoadingUpdate(void) {
+  if(UI_LOADING.duration > 0.0f && UI_LOADING.time < UI_LOADING.duration) {
+    UI_LOADING.time += TIME.delta;
+    if(UI_LOADING.time >= UI_LOADING.duration) {
+      UI_LOADING.time = UI_LOADING.duration;
+      eventInvoke(&UI_LOADING.onTransitionEnd, &UI_LOADING);
+    }
+  }
+  errorOk();
+}
+
+errorret_t uiLoadingDraw(void) {
+  float_t alpha;
+  if(UI_LOADING.duration <= 0.0f || UI_LOADING.time >= UI_LOADING.duration) {
+    alpha = UI_LOADING.toAlpha;
+  } else {
+    float_t t = UI_LOADING.time / UI_LOADING.duration;
+    alpha = UI_LOADING.fromAlpha +
+      (UI_LOADING.toAlpha - UI_LOADING.fromAlpha) * t;
+  }
+
+  if(alpha <= 0.0f) errorOk();
+
+  int32_t textW, textH;
+  uiLabelGetSize(&UI_LOADING.textLabel, &textW, &textH);
+
+  float_t x = (float_t)(SCREEN.scanX + SCREEN.scanWidth) -
+    (float_t)textW - UI_LOADING_MARGIN;
+  float_t y = (float_t)(SCREEN.scanY + SCREEN.scanHeight) -
+    (float_t)textH - UI_LOADING_MARGIN;
+
+  color_t color = COLOR_WHITE;
+  color.a = (uint8_t)(alpha * 255.0f);
+  uiLabelSetColor(&UI_LOADING.textLabel, color);
+
+  errorChain(uiLabelDraw(&UI_LOADING.textLabel, x, y));
+  errorOk();
+}
+
+static void uiLoadingTransition(
+  const float_t from,
+  const float_t to,
+  const eventcallback_t callback,
+  void *user
+) {
+  UI_LOADING.fromAlpha = from;
+  UI_LOADING.toAlpha = to;
+  UI_LOADING.duration = UI_LOADING_FADE_DURATION;
+  UI_LOADING.time = 0.0f;
+  eventInit(
+    &UI_LOADING.onTransitionEnd,
+    UI_LOADING.onTransitionEndCallbacks,
+    UI_LOADING.onTransitionEndUsers,
+    4
+  );
+  if(callback) eventSubscribe(&UI_LOADING.onTransitionEnd, callback, user);
+}
+
+void uiLoadingShow(eventcallback_t callback, void *user) {
+  uiLoadingTransition(0.0f, 1.0f, callback, user);
+  uiFullboxTransition(
+    &UI_FULLBOX_OVER,
+    COLOR_TRANSPARENT_BLACK,
+    COLOR_BLACK,
+    UI_LOADING_FADE_DURATION,
+    EASING_LINEAR
+  );
+}
+
+void uiLoadingHide(eventcallback_t callback, void *user) {
+  uiLoadingTransition(1.0f, 0.0f, callback, user);
+  uiFullboxTransition(
+    &UI_FULLBOX_OVER,
+    COLOR_BLACK,
+    COLOR_TRANSPARENT_BLACK,
+    UI_LOADING_FADE_DURATION,
+    EASING_LINEAR
+  );
+}

archive/dusk/ui/overlay/uiloading.h

@@ -0,0 +1,65 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "event/event.h"
+#include "ui/widget/uilabel.h"
+
+#define UI_LOADING_FADE_DURATION 0.5f
+#define UI_LOADING_MARGIN 8.0f
+
+typedef struct {
+  float_t fromAlpha;
+  float_t toAlpha;
+  float_t duration;
+  float_t time;
+  eventcallback_t onTransitionEndCallbacks[4];
+  void *onTransitionEndUsers[4];
+  event_t onTransitionEnd;
+  uilabel_t textLabel;
+} uiloading_t;
+
+extern uiloading_t UI_LOADING;
+
+/**
+ * Initializes the loading indicator.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiLoadingInit(void);
+
+/**
+ * Advances the loading indicator fade transition. Fires onTransitionEnd once
+ * when the transition completes.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiLoadingUpdate(void);
+
+/**
+ * Draws the loading indicator. No-op when fully transparent.
+ *
+ * @return Error state.
+ */
+errorret_t uiLoadingDraw(void);
+
+/**
+ * Fades the loading indicator in. Invokes callback when fully visible.
+ *
+ * @param callback Called when the fade-in completes. May be NULL.
+ * @param user     Forwarded to the callback unchanged.
+ */
+void uiLoadingShow(eventcallback_t callback, void *user);
+
+/**
+ * Fades the loading indicator out. Invokes callback when fully hidden.
+ *
+ * @param callback Called when the fade-out completes. May be NULL.
+ * @param user     Forwarded to the callback unchanged.
+ */
+void uiLoadingHide(eventcallback_t callback, void *user);

archive/dusk/ui/transition/CMakeLists.txt

@@ -0,0 +1,10 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    uitransition.c
+    uitransitionfade.c
+)

archive/dusk/ui/transition/uitransition.c

@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uitransition.h"
+#include "uitransitionfade.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "time/time.h"
+#include "util/math.h"
+
+uitransition_t UI_TRANSITION;
+
+uitransitiondrawfunc_t UI_TRANSITION_TYPE_DRAW[UI_TRANSITION_TYPE_COUNT] = {
+  [UI_TRANSITION_TYPE_FADE] = uiTransitionFadeDraw
+};
+
+errorret_t uiTransitionInit(void) {
+  memoryZero(&UI_TRANSITION, sizeof(uitransition_t));
+
+  // uiTransitionStart((uitransitionstartparams_t){
+  //   .duration = 5.0f,
+  //   .type = UI_TRANSITION_TYPE_FADE,
+  //   .params = {
+  //     .fade = {
+  //       .easing = EASING_OUT_QUART,
+  //       .fromColor = COLOR_TRANSPARENT_BLACK,
+  //       .toColor = COLOR_BLACK
+  //     }
+  //   },
+  //   .finished = NULL,
+  //   .user = NULL
+  // });
+
+  errorOk();
+}
+
+errorret_t uiTransitionUpdate(void) {
+  // Update time.
+  float_t newTime = UI_TRANSITION.data.time + TIME.delta;
+
+  UI_TRANSITION.data.time = mathClamp(
+    newTime,
+    0.0f,
+    UI_TRANSITION.data.duration
+  );
+  UI_TRANSITION.data.t = (
+    (UI_TRANSITION.data.duration <= 0.0f) ?
+    1.0f :
+    (UI_TRANSITION.data.time / UI_TRANSITION.data.duration)
+  );
+
+  if(UI_TRANSITION.data.t >= 1.0f && UI_TRANSITION.finished) {
+    UI_TRANSITION.finished(UI_TRANSITION.user);
+  }
+
+  errorOk();
+}
+
+errorret_t uiTransitionDraw(void) {
+  uitransitiondrawfunc_t draw = UI_TRANSITION_TYPE_DRAW[UI_TRANSITION.type];
+  if(!draw) errorOk();
+  return draw(&UI_TRANSITION.data);
+}
+
+void uiTransitionStart(const uitransitionstartparams_t info) {
+  assertTrue(info.type > UI_TRANSITION_TYPE_NULL, "Invalid type");
+  assertTrue(info.type < UI_TRANSITION_TYPE_COUNT, "Invalid type");
+  assertTrue(info.duration >= 0.0f, "Duration must be non-negative");
+
+  memoryZero(&UI_TRANSITION, sizeof(uitransition_t));
+
+  UI_TRANSITION.data.duration = info.duration;
+  UI_TRANSITION.type = info.type;
+  UI_TRANSITION.data.params = info.params;
+  UI_TRANSITION.finished = info.finished;
+  UI_TRANSITION.user = info.user;
+}

archive/dusk/ui/transition/uitransition.h

@@ -0,0 +1,74 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "display/color.h"
+#include "animation/easing.h"
+#include "uitransitiondata.h"
+
+typedef void (*uitransitioncallback_t)(void *user);
+
+typedef enum {
+  UI_TRANSITION_TYPE_NULL,
+
+  UI_TRANSITION_TYPE_FADE,
+
+  UI_TRANSITION_TYPE_COUNT
+} uitransitiontype_t;
+
+extern uitransitiondrawfunc_t UI_TRANSITION_TYPE_DRAW[UI_TRANSITION_TYPE_COUNT];
+
+
+typedef struct {
+  uitransitiondata_t data;
+  uitransitiontype_t type;
+  uitransitioncallback_t finished;
+  void *user;
+} uitransition_t;
+
+extern uitransition_t UI_TRANSITION;
+
+/**
+ * Initializes the transition overlay, zeroing all fields and wiring the
+ * onTransitionEnd event.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiTransitionInit(void);
+
+/**
+ * Advances the transition. Fires onTransitionEnd once when it completes.
+ * Safe to call when no transition is running.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiTransitionUpdate(void);
+
+/**
+ * Renders the transition overlay. Skipped entirely when the current alpha
+ * is zero.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiTransitionDraw(void);
+
+typedef struct {
+  float_t duration;
+  uitransitiontype_t type;
+  uitransitionparams_t params;
+  uitransitioncallback_t finished;
+  void *user;
+} uitransitionstartparams_t;
+
+/**
+ * Starts a transition described by an info struct.
+ *
+ * @param info Transition parameters.
+ */
+void uiTransitionStart(const uitransitionstartparams_t info);
+

archive/dusk/ui/transition/uitransitiondata.h

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "uitransitionfade.h"
+
+typedef union uitransitionparams_u {
+  uitransitionfade_t fade;
+} uitransitionparams_t;
+
+typedef struct uitransitiondata_s {
+  float_t time;
+  float_t duration;
+  float_t t;
+  uitransitionparams_t params;
+} uitransitiondata_t;
+
+typedef errorret_t (*uitransitiondrawfunc_t)(const uitransitiondata_t *data);

archive/dusk/ui/transition/uitransitionfade.c

@@ -0,0 +1,56 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uitransition.h"
+#include "assert/assert.h"
+#include "display/screen/screen.h"
+#include "display/texture/texture.h"
+#include "display/spritebatch/spritebatch.h"
+#include "display/shader/shaderunlit.h"
+
+errorret_t uiTransitionFadeDraw(const uitransitiondata_t *data) {
+  assertNotNull(data, "data must not be NULL");
+
+  float_t e = easingApply(data->params.fade.easing, data->t);
+
+  float_t r = (float_t)(
+    data->params.fade.toColor.r - data->params.fade.fromColor.r
+  ) * e;
+  float_t g = (float_t)(
+    data->params.fade.toColor.g - data->params.fade.fromColor.g
+  ) * e;
+  float_t b = (float_t)(
+    data->params.fade.toColor.b - data->params.fade.fromColor.b
+  ) * e;
+  float_t a = (float_t)(
+    data->params.fade.toColor.a - data->params.fade.fromColor.a
+  ) * e;
+
+  color_t color = color4b(
+    data->params.fade.fromColor.r + (uint8_t)r,
+    data->params.fade.fromColor.g + (uint8_t)g,
+    data->params.fade.fromColor.b + (uint8_t)b,
+    data->params.fade.fromColor.a + (uint8_t)a
+  );
+
+  if(color.a == 0) errorOk();
+
+  spritebatchsprite_t sprite = {
+    .min = { 0.0f, 0.0f, 0.0f },
+    .max = { (float_t)SCREEN.width, (float_t)SCREEN.height, 0.0f },
+    .uvMin = { 0.0f, 0.0f },
+    .uvMax = { 1.0f, 1.0f }
+  };
+  shadermaterial_t material = {
+    .unlit = {
+      .color = color,
+      .texture = NULL
+    }
+  };
+  errorChain(spriteBatchBuffer(&sprite, 1, &SHADER_UNLIT, material));
+  errorOk();
+}

archive/dusk/ui/transition/uitransitionfade.h

@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "display/color.h"
+#include "animation/easing.h"
+
+typedef struct uitransitiondata_s uitransitiondata_t;
+
+typedef struct {
+  color_t fromColor;
+  color_t toColor;
+  easingtype_t easing;
+} uitransitionfade_t;
+
+/**
+ * Renders a full-screen color overlay interpolated between fade->fromColor
+ * and fade->toColor using fade->easing. t is the raw normalized progress
+ * in [0, 1] before easing is applied. No-op when the resulting alpha is zero.
+ *
+ * @param fade The fade parameters.
+ * @return Any error that occurs.
+ */
+errorret_t uiTransitionFadeDraw(const uitransitiondata_t *fade);

archive/dusk/ui/ui.c

@@ -0,0 +1,62 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "ui.h"
+#include "util/memory.h"
+#include "assert/assert.h"
+#include "display/spritebatch/spritebatch.h"
+#include "display/screen/screen.h"
+#include "ui/uielement.h"
+#include "ui/focus/uifocus.h"
+
+ui_t UI;
+
+errorret_t uiInit(void) {
+  memoryZero(&UI, sizeof(ui_t));
+  uiFocusInit();
+  uiElementsSort();
+
+  uielement_t *element = &UI_ELEMENTS[0];
+  while(!uiElementIsNull(element)) {
+    errorChain(uiElementInit(element));
+    element++;
+  }
+
+  errorOk();
+}
+
+errorret_t uiUpdate(void) {
+  uiFocusUpdate();
+
+  uielement_t *element = &UI_ELEMENTS[0];
+  while(!uiElementIsNull(element)) {
+    errorChain(uiElementUpdate(element));
+    element++;
+  }
+
+  errorOk();
+}
+
+errorret_t uiRender(void) {
+  const uielement_t *element = &UI_ELEMENTS[0];
+  while(!uiElementIsNull(element)) {
+    errorChain(uiElementDraw(element));
+    element++;
+  }
+
+  errorChain(spriteBatchFlush());
+  errorOk();
+}
+
+errorret_t uiDispose(void) {
+  uielement_t *element = &UI_ELEMENTS[0];
+  while(!uiElementIsNull(element)) {
+    errorChain(uiElementDispose(element));
+    element++;
+  }
+  errorOk();
+}

archive/dusk/ui/ui.h

@@ -0,0 +1,41 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+
+typedef struct {
+  void *nothing;
+} ui_t;
+
+extern ui_t UI;
+
+/**
+ * Initializes the UI system.
+ */
+errorret_t uiInit(void);
+
+/**
+ * Updates the UI system.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiUpdate(void);
+
+/**
+ * Renders the UI system.
+ * 
+ * @return Any error that occurs.
+ */
+errorret_t uiRender(void);
+
+/**
+ * Disposes of the UI system.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiDispose(void);

archive/dusk/ui/uielement.c

@@ -0,0 +1,86 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uielement.h"
+#include "assert/assert.h"
+#include "util/sort.h"
+#include "ui/frame/uiframe.h"
+#include "ui/debug/uifps.h"
+#include "engine/engine.h"
+#include "ui/overlay/uifullbox.h"
+#include "ui/overlay/uiloading.h"
+#include "ui/overlay/uicrop.h"
+#include "ui/transition/uitransition.h"
+#include "ui/debug/uiconsole.h"
+#include "ui/frame/uiconfirm.h"
+
+// Priming pass: X does nothing here, so this only exists to process any
+// #include directives nested in uielementlist.h/ui/uielementgame.h at
+// file scope (each such header's own #pragma once makes it a no-op on
+// the real pass below, which happens inside UI_ELEMENTS[]'s braces,
+// where a raw #include of a declaration would be invalid).
+#define X(initFn, updateFn, drawFn, disposeFn, order) // do nothing
+#include "uielementlist.h"
+#undef X
+
+uielement_t UI_ELEMENTS[] = {
+  #define X(initFn, updateFn, drawFn, disposeFn, elementOrder) \
+    { \
+      .init = initFn, .update = updateFn, .draw = drawFn, \
+      .dispose = disposeFn, .order = elementOrder \
+    },
+  #include "uielementlist.h"
+  #undef X
+
+  { 0 } // Null terminator
+};
+
+bool_t uiElementIsNull(const uielement_t *element) {
+  return element->init == NULL &&
+    element->update == NULL &&
+    element->draw == NULL &&
+    element->dispose == NULL;
+}
+
+int_t uiElementCompareOrder(const void *a, const void *b) {
+  const uielement_t *elementA = (const uielement_t *)a;
+  const uielement_t *elementB = (const uielement_t *)b;
+  if(elementA->order < elementB->order) return -1;
+  if(elementA->order > elementB->order) return 1;
+  return 0;
+}
+
+void uiElementsSort(void) {
+  // The trailing null terminator is always the last static entry -- sort
+  // everything before it, and leave it in place.
+  const size_t count = (sizeof(UI_ELEMENTS) / sizeof(UI_ELEMENTS[0])) - 1;
+  sortBubble(UI_ELEMENTS, count, sizeof(uielement_t), uiElementCompareOrder);
+}
+
+errorret_t uiElementInit(uielement_t *element) {
+  assertNotNull(element, "element must not be NULL");
+  if(element->init != NULL) errorChain(element->init());
+  errorOk();
+}
+
+errorret_t uiElementUpdate(uielement_t *element) {
+  assertNotNull(element, "element must not be NULL");
+  if(element->update != NULL) errorChain(element->update());
+  errorOk();
+}
+
+errorret_t uiElementDraw(const uielement_t *element) {
+  assertNotNull(element, "element must not be NULL");
+  if(element->draw != NULL) errorChain(element->draw());
+  errorOk();
+}
+
+errorret_t uiElementDispose(uielement_t *element) {
+  assertNotNull(element, "element must not be NULL");
+  if(element->dispose != NULL) errorChain(element->dispose());
+  errorOk();
+}

archive/dusk/ui/uielement.h

@@ -0,0 +1,84 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+
+// Built-in order tiers. Lower values update/render first; ties preserve
+// their relative UI_ELEMENTS declaration order (uiElementsSort uses a
+// stable sort). Game-specific elements can use any int32_t value -- these
+// are just the ones the engine itself relies on.
+#define UI_ELEMENT_ORDER_DEFAULT 0
+#define UI_ELEMENT_ORDER_DEBUG   1000
+
+typedef struct {
+  errorret_t (*init)();
+  errorret_t (*update)();
+  errorret_t (*draw)();
+  errorret_t (*dispose)();
+  int32_t order;
+} uielement_t;
+
+extern uielement_t UI_ELEMENTS[];
+
+/**
+ * Returns true when all four callbacks on the element are NULL,
+ * which marks the end of the UI_ELEMENTS array.
+ *
+ * @param element The element to test.
+ * @returns True if the element is the null terminator.
+ */
+bool_t uiElementIsNull(const uielement_t *element);
+
+/**
+ * Compares two elements by their .order field, ascending. Matches
+ * sortcompare_t, for use with the project's sort utilities.
+ *
+ * @param a First uielement_t to compare.
+ * @param b Second uielement_t to compare.
+ * @return Negative if a < b, zero if a == b, positive if a > b.
+ */
+int_t uiElementCompareOrder(const void *a, const void *b);
+
+/**
+ * Stably sorts UI_ELEMENTS in place by .order, ascending. The trailing
+ * null terminator is never moved. Called once by uiInit -- element order
+ * is static after that, so there's no need to re-sort every frame.
+ */
+void uiElementsSort(void);
+
+/**
+ * Initializes a UI element, invoking its init callback if set.
+ *
+ * @param element The element to initialize.
+ * @return Any error that occurs.
+ */
+errorret_t uiElementInit(uielement_t *element);
+
+/**
+ * Updates a UI element, calling its update callback if set.
+ *
+ * @param element The element to update.
+ * @return Any error that occurs.
+ */
+errorret_t uiElementUpdate(uielement_t *element);
+
+/**
+ * Draws a UI element, calling its draw callback if set.
+ *
+ * @param element The element to render.
+ * @return Any error that occurs.
+ */
+errorret_t uiElementDraw(const uielement_t *element);
+
+/**
+ * Disposes of a UI element, invoking its dispose callback if set.
+ *
+ * @param element The element to dispose.
+ * @return Any error that occurs.
+ */
+errorret_t uiElementDispose(uielement_t *element);

archive/dusk/ui/uielementlist.h

@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+// X(init, update, draw, dispose, order) -- pass NULL for any callback the
+// element doesn't need. order controls update/draw sequence (lower first,
+// see UI_ELEMENT_ORDER_* in uielement.h); ties preserve declaration order.
+// See uielement.c for how this expands.
+
+X(uiFrameInit, NULL, NULL, uiFrameDispose, UI_ELEMENT_ORDER_DEFAULT)
+
+// Fullbox under: above scene, below system UI.
+X(
+  uiFullboxUnderInit, uiFullboxUnderUpdate, uiFullboxUnderDraw, NULL,
+  UI_ELEMENT_ORDER_DEFAULT
+)
+
+// Text stuffs
+X(uiConfirmInit, NULL, uiConfirmDraw, uiConfirmDispose, UI_ELEMENT_ORDER_DEFAULT)
+
+X(
+  uiTransitionInit, uiTransitionUpdate, uiTransitionDraw, NULL,
+  UI_ELEMENT_ORDER_DEFAULT
+)
+
+// Fullbox over: above absolutely everything (except debug).
+X(
+  uiFullboxOverInit, uiFullboxOverUpdate, uiFullboxOverDraw, NULL,
+  UI_ELEMENT_ORDER_DEFAULT
+)
+
+X(
+  uiLoadingInit, uiLoadingUpdate, uiLoadingDraw, NULL,
+  UI_ELEMENT_ORDER_DEFAULT
+)
+
+X(uiCropInit, NULL, uiCropDraw, NULL, UI_ELEMENT_ORDER_DEFAULT)
+
+// Debug items -- always last.
+X(NULL, NULL, uiConsoleDraw, uiConsoleDispose, UI_ELEMENT_ORDER_DEBUG)
+X(uiFPSInit, NULL, uiFPSDraw, NULL, UI_ELEMENT_ORDER_DEBUG)
+
+// Game-specific UI elements (duskrpg)
+#include "ui/uielementgame.h"

archive/dusk/ui/widget/CMakeLists.txt

@@ -0,0 +1,17 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    uibutton.c
+    uicheckbox.c
+    uitab.c
+    uislider.c
+    uidropdown.c
+    uiscrolling.c
+    uimenu.c
+    uilabel.c
+    uiwidgetlabel.c
+)

archive/dusk/ui/widget/uibutton.c

@@ -7,15 +7,15 @@
 
 #include "uibutton.h"
 #include "assert/assert.h"
-#include "util/memory.h"
 #include "display/text/text.h"
 #include "display/color.h"
 
 void uiButtonInit(uibutton_t *button, const char_t *label) {
   assertNotNull(button, "Button cannot be NULL");
   assertNotNull(label, "Label cannot be NULL");
-  memoryZero(button, sizeof(uibutton_t));
-  button->label = label;
+  uiWidgetLabelInit(&button->label, &FONT_DEFAULT);
+  uiWidgetLabelSetText(&button->label, label);
+  button->highlighted = false;
 }
 
 bool_t uiButtonIsHighlighted(const uibutton_t *button) {
@@ -26,6 +26,9 @@ bool_t uiButtonIsHighlighted(const uibutton_t *button) {
 void uiButtonSetHighlighted(uibutton_t *button, const bool_t highlighted) {
   assertNotNull(button, "Button cannot be NULL");
   button->highlighted = highlighted;
+  uiWidgetLabelSetColor(
+    &button->label, highlighted ? COLOR_RED : COLOR_WHITE
+  );
 }
 
 errorret_t uiButtonDraw(
@@ -34,10 +37,6 @@ errorret_t uiButtonDraw(
   const float_t y
 ) {
   assertNotNull(button, "Button cannot be NULL");
-  errorChain(textDraw(
-    x, y, button->label,
-    button->highlighted ? COLOR_RED : COLOR_WHITE,
-    &FONT_DEFAULT
-  ));
+  errorChain(uiWidgetLabelDraw(&button->label, x, y));
   errorOk();
 }

archive/dusk/ui/widget/uibutton.h

@@ -7,9 +7,10 @@
 
 #pragma once
 #include "error/error.h"
+#include "ui/widget/uiwidgetlabel.h"
 
 typedef struct {
-  const char_t *label;
+  uiwidgetlabel_t label;
   bool_t highlighted;
 } uibutton_t;
 

archive/dusk/ui/widget/uicheckbox.c

@@ -7,6 +7,7 @@
 
 #include "uicheckbox.h"
 #include "util/memory.h"
+#include "util/string.h"
 #include "display/text/text.h"
 #include "display/color.h"
 
@@ -15,7 +16,9 @@ void uiCheckboxInit(
   const char_t *label
 ) {
   memoryZero(checkbox, sizeof(uicheckbox_t));
-  checkbox->label = label;
+  checkbox->rawLabel = label;
+  uiWidgetLabelInit(&checkbox->label, &FONT_DEFAULT);
+  uiCheckboxRebuildLabel(checkbox);
 }
 
 bool_t uiCheckboxIsChecked(const uicheckbox_t *checkbox) {
@@ -24,6 +27,7 @@ bool_t uiCheckboxIsChecked(const uicheckbox_t *checkbox) {
 
 void uiCheckboxSetChecked(uicheckbox_t *checkbox, const bool_t checked) {
   checkbox->checked = checked;
+  uiCheckboxRebuildLabel(checkbox);
 }
 
 void uiCheckboxToggle(uicheckbox_t *checkbox) {
@@ -36,6 +40,9 @@ bool_t uiCheckboxIsHighlighted(const uicheckbox_t *checkbox) {
 
 void uiCheckboxSetHighlighted(uicheckbox_t *checkbox, const bool_t highlighted) {
   checkbox->highlighted = highlighted;
+  uiWidgetLabelSetColor(
+    &checkbox->label, highlighted ? COLOR_RED : COLOR_WHITE
+  );
 }
 
 errorret_t uiCheckboxDraw(
@@ -43,15 +50,15 @@ errorret_t uiCheckboxDraw(
   const float_t x,
   const float_t y
 ) {
-  color_t color = checkbox->highlighted ? COLOR_RED : COLOR_WHITE;
-  const char_t *mark = checkbox->checked ? "Y " : "N ";
-  errorChain(textDraw(x, y, mark, color, &FONT_DEFAULT));
-
-  int32_t markW, markH;
-  textMeasure(mark, &FONT_DEFAULT, &markW, &markH);
-  errorChain(textDraw(
-    x + (float_t)markW, y, checkbox->label, color, &FONT_DEFAULT
-  ));
-
+  errorChain(uiWidgetLabelDraw(&checkbox->label, x, y));
   errorOk();
 }
+
+void uiCheckboxRebuildLabel(uicheckbox_t *checkbox) {
+  char_t combined[UI_WIDGET_LABEL_TEXT_MAX];
+  stringFormat(
+    combined, UI_WIDGET_LABEL_TEXT_MAX - 1, "%s %s",
+    checkbox->checked ? "Y" : "N", checkbox->rawLabel
+  );
+  uiWidgetLabelSetText(&checkbox->label, combined);
+}

archive/dusk/ui/widget/uicheckbox.h

@@ -7,9 +7,11 @@
 
 #pragma once
 #include "error/error.h"
+#include "ui/widget/uiwidgetlabel.h"
 
 typedef struct uicheckbox_s {
-  const char_t *label;
+  const char_t *rawLabel;
+  uiwidgetlabel_t label;
   bool_t checked;
   bool_t highlighted;
 } uicheckbox_t;
@@ -77,3 +79,12 @@ errorret_t uiCheckboxDraw(
   const float_t x,
   const float_t y
 );
+
+/**
+ * Rebuilds the checkbox's cached label ("Y "/"N " mark plus rawLabel)
+ * from its current checked state. Called internally whenever checked
+ * changes.
+ *
+ * @param checkbox The checkbox to update.
+ */
+void uiCheckboxRebuildLabel(uicheckbox_t *checkbox);

archive/dusk/ui/widget/uidropdown.c

@@ -25,13 +25,13 @@ void uiDropdownInit(
   assertTrue(optionCount > 0, "Dropdown must have at least one option");
 
   memoryZero(dropdown, sizeof(uidropdown_t));
-  dropdown->label = label;
+  uiWidgetLabelInit(&dropdown->label, &FONT_DEFAULT);
+  uiWidgetLabelSetText(&dropdown->label, label);
+  uiWidgetLabelInit(&dropdown->value, &FONT_DEFAULT);
   dropdown->options = options;
   dropdown->optionCount = optionCount;
   dropdown->selectedIndex = selectedIndex < optionCount ? selectedIndex : 0;
-  textMeasure(
-    label, &FONT_DEFAULT, &dropdown->labelWidth, &dropdown->labelHeight
-  );
+  uiDropdownRebuildValue(dropdown);
 }
 
 uint8_t uiDropdownGetSelectedIndex(const uidropdown_t *dropdown) {
@@ -48,18 +48,21 @@ void uiDropdownSetSelectedIndex(uidropdown_t *dropdown, const uint8_t index) {
   assertNotNull(dropdown, "Dropdown cannot be NULL");
   assertTrue(index < dropdown->optionCount, "Dropdown index out of range");
   dropdown->selectedIndex = index;
+  uiDropdownRebuildValue(dropdown);
 }
 
 void uiDropdownStepNext(uidropdown_t *dropdown) {
   assertNotNull(dropdown, "Dropdown cannot be NULL");
   dropdown->selectedIndex =
     (dropdown->selectedIndex + 1) % dropdown->optionCount;
+  uiDropdownRebuildValue(dropdown);
 }
 
 void uiDropdownStepPrev(uidropdown_t *dropdown) {
   assertNotNull(dropdown, "Dropdown cannot be NULL");
   dropdown->selectedIndex = dropdown->selectedIndex == 0 ?
     dropdown->optionCount - 1 : dropdown->selectedIndex - 1;
+  uiDropdownRebuildValue(dropdown);
 }
 
 bool_t uiDropdownIsHighlighted(const uidropdown_t *dropdown) {
@@ -73,6 +76,9 @@ void uiDropdownSetHighlighted(
 ) {
   assertNotNull(dropdown, "Dropdown cannot be NULL");
   dropdown->highlighted = highlighted;
+  color_t color = highlighted ? COLOR_RED : COLOR_WHITE;
+  uiWidgetLabelSetColor(&dropdown->label, color);
+  uiWidgetLabelSetColor(&dropdown->value, color);
 }
 
 errorret_t uiDropdownDraw(
@@ -82,20 +88,23 @@ errorret_t uiDropdownDraw(
 ) {
   assertNotNull(dropdown, "Dropdown cannot be NULL");
 
-  color_t color = dropdown->highlighted ? COLOR_RED : COLOR_WHITE;
+  errorChain(uiWidgetLabelDraw(&dropdown->label, x, y));
 
-  errorChain(textDraw(x, y, dropdown->label, color, &FONT_DEFAULT));
+  int32_t labelW, labelH;
+  uiWidgetLabelGetSize(&dropdown->label, &labelW, &labelH);
 
-  char_t valueText[UI_DROPDOWN_VALUE_TEXT_MAX];
-  stringFormat(
-    valueText, UI_DROPDOWN_VALUE_TEXT_MAX - 1, "< %s >",
-    uiDropdownGetSelectedOption(dropdown)
-  );
-
-  errorChain(textDraw(
-    x + (float_t)dropdown->labelWidth + UI_DROPDOWN_GAP, y, valueText, color,
-    &FONT_DEFAULT
+  errorChain(uiWidgetLabelDraw(
+    &dropdown->value, x + (float_t)labelW + UI_DROPDOWN_GAP, y
   ));
 
   errorOk();
 }
+
+void uiDropdownRebuildValue(uidropdown_t *dropdown) {
+  char_t valueText[UI_WIDGET_LABEL_TEXT_MAX];
+  stringFormat(
+    valueText, UI_WIDGET_LABEL_TEXT_MAX - 1, "< %s >",
+    uiDropdownGetSelectedOption(dropdown)
+  );
+  uiWidgetLabelSetText(&dropdown->value, valueText);
+}

archive/dusk/ui/widget/uidropdown.h

@@ -7,18 +7,17 @@
 
 #pragma once
 #include "error/error.h"
+#include "ui/widget/uiwidgetlabel.h"
 
 #define UI_DROPDOWN_GAP 4.0f
-#define UI_DROPDOWN_VALUE_TEXT_MAX 64
 
 typedef struct {
-  const char_t *label;
+  uiwidgetlabel_t label;
+  uiwidgetlabel_t value;
   const char_t *const *options;
   uint8_t optionCount;
   uint8_t selectedIndex;
   bool_t highlighted;
-  int32_t labelWidth;
-  int32_t labelHeight;
 } uidropdown_t;
 
 /**
@@ -113,3 +112,12 @@ errorret_t uiDropdownDraw(
   const float_t x,
   const float_t y
 );
+
+/**
+ * Rebuilds the dropdown's cached value label ("< option >") from its
+ * current selectedIndex. Called internally whenever selectedIndex
+ * changes.
+ *
+ * @param dropdown The dropdown to update.
+ */
+void uiDropdownRebuildValue(uidropdown_t *dropdown);

archive/dusk/ui/widget/uilabel.c

@@ -0,0 +1,70 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uilabel.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "util/string.h"
+#include "display/text/text.h"
+
+void uiLabelInit(uilabel_t *label, font_t *font) {
+  assertNotNull(label, "Label cannot be NULL");
+  assertNotNull(font, "Font cannot be NULL");
+
+  memoryZero(label, sizeof(uilabel_t));
+  label->font = font;
+  label->color = COLOR_WHITE;
+}
+
+void uiLabelSetText(uilabel_t *label, const char_t *text) {
+  assertNotNull(label, "Label cannot be NULL");
+  assertNotNull(text, "Text cannot be NULL");
+  assertStrLenMax(text, UI_LABEL_TEXT_MAX, "Label text too long");
+
+  stringCopy(label->text, text, UI_LABEL_TEXT_MAX);
+  label->spriteCount = textBuildSpriteCache(
+    label->text, label->font, label->sprites, UI_LABEL_SPRITE_COUNT_MAX,
+    &label->width, &label->height
+  );
+}
+
+void uiLabelSetColor(uilabel_t *label, const color_t color) {
+  assertNotNull(label, "Label cannot be NULL");
+  label->color = color;
+}
+
+void uiLabelGetSize(
+  const uilabel_t *label,
+  int32_t *outWidth,
+  int32_t *outHeight
+) {
+  assertNotNull(label, "Label cannot be NULL");
+  assertNotNull(outWidth, "Output width cannot be NULL");
+  assertNotNull(outHeight, "Output height cannot be NULL");
+  *outWidth = label->width;
+  *outHeight = label->height;
+}
+
+errorret_t uiLabelDraw(
+  const uilabel_t *label,
+  const float_t x,
+  const float_t y
+) {
+  assertNotNull(label, "Label cannot be NULL");
+  if(label->spriteCount == 0) errorOk();
+
+  // Cached sprites are relative to (0,0); textDrawSpriteCache translates
+  // into the requested screen position here instead of in
+  // uiLabelSetText, so a label can be repositioned every frame without
+  // rebuilding the (much more expensive) glyph/UV cache.
+  spritebatchsprite_t scratch[UI_LABEL_SPRITE_COUNT_MAX];
+  errorChain(textDrawSpriteCache(
+    label->sprites, label->spriteCount, scratch, x, y, label->color,
+    label->font->texture
+  ));
+  errorOk();
+}

archive/dusk/ui/widget/uilabel.h

@@ -0,0 +1,85 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "display/text/font.h"
+#include "display/spritebatch/spritebatchsprite.h"
+#include "display/color.h"
+
+#define UI_LABEL_TEXT_MAX 256
+#define UI_LABEL_SPRITE_COUNT_MAX UI_LABEL_TEXT_MAX
+
+typedef struct {
+  char_t text[UI_LABEL_TEXT_MAX];
+  color_t color;
+  font_t *font;
+
+  spritebatchsprite_t sprites[UI_LABEL_SPRITE_COUNT_MAX];
+  uint32_t spriteCount;
+  int32_t width;
+  int32_t height;
+} uilabel_t;
+
+/**
+ * Initializes a label, defaulting to white text and no text set.
+ *
+ * @param label The label to initialize.
+ * @param font Font to use for rendering. Must outlive the label.
+ */
+void uiLabelInit(uilabel_t *label, font_t *font);
+
+/**
+ * Sets the label's text, rebuilding its cached sprites (glyph lookup, UV,
+ * and layout) immediately. This is the only way the sprite cache gets
+ * rebuilt -- uiLabelDraw never recomputes it, so call this whenever the
+ * text changes rather than once up front and expecting it to stay in sync.
+ *
+ * @param label The label to update.
+ * @param text Null-terminated string to display. Must be shorter than
+ * UI_LABEL_TEXT_MAX.
+ */
+void uiLabelSetText(uilabel_t *label, const char_t *text);
+
+/**
+ * Sets the label's tint color. Cheap -- doesn't touch the sprite cache,
+ * since color is applied via the draw material, not baked into sprites.
+ *
+ * @param label The label to update.
+ * @param color The new tint color.
+ */
+void uiLabelSetColor(uilabel_t *label, const color_t color);
+
+/**
+ * Gets the measured size (in pixels) of the label's current text, cached
+ * from the last uiLabelSetText call.
+ *
+ * @param label The label to query.
+ * @param outWidth Pointer to store the width.
+ * @param outHeight Pointer to store the height.
+ */
+void uiLabelGetSize(
+  const uilabel_t *label,
+  int32_t *outWidth,
+  int32_t *outHeight
+);
+
+/**
+ * Draws the label's cached sprites at the given screen position in a
+ * single batched buffer call. Does not recompute glyph layout -- call
+ * uiLabelSetText first whenever the text changes.
+ *
+ * @param label The label to draw.
+ * @param x Screen x position.
+ * @param y Screen y position.
+ * @return Any error that occurs.
+ */
+errorret_t uiLabelDraw(
+  const uilabel_t *label,
+  const float_t x,
+  const float_t y
+);

archive/dusk/ui/widget/uimenu.c

@@ -10,6 +10,7 @@
 #include "util/memory.h"
 #include "display/text/text.h"
 #include "display/color.h"
+#include "ui/widget/uiwidgetlabel.h"
 #include "ui/widget/uibutton.h"
 #include "ui/widget/uitab.h"
 #include "ui/widget/uislider.h"
@@ -102,12 +103,8 @@ errorret_t uiMenuDraw(
 
     if(item->type == UI_MENU_WIDGET_TYPE_LABEL) {
       if(col > 0) { row++; col = 0; }
-      errorChain(textDraw(
-        x,
-        y + (float_t)row * rowHeight,
-        item->label,
-        COLOR_WHITE,
-        &FONT_DEFAULT
+      errorChain(uiWidgetLabelDraw(
+        &item->label, x, y + (float_t)row * rowHeight
       ));
       row++;
       continue;
@@ -274,6 +271,13 @@ uint8_t uiMenuFocusSlotToIndex(const uimenu_t *menu, const uint8_t slot) {
   return 0xFF;
 }
 
+void uiMenuLabelInit(uimenuitem_t *item, const char_t *text) {
+  assertNotNull(item, "Item cannot be NULL");
+  assertNotNull(text, "Text cannot be NULL");
+  uiWidgetLabelInit(&item->label, &FONT_DEFAULT);
+  uiWidgetLabelSetText(&item->label, text);
+}
+
 void uiMenuItemSetHighlighted(uimenuitem_t *item, const bool_t highlighted) {
   if(item->type == UI_MENU_WIDGET_TYPE_CHECKBOX) {
     uiCheckboxSetHighlighted(&item->checkbox, highlighted);

archive/dusk/ui/widget/uimenu.h

@@ -8,14 +8,13 @@
 #pragma once
 #include "error/error.h"
 #include "ui/focus/uifocus.h"
+#include "ui/widget/uiwidgetlabel.h"
 #include "ui/widget/uibutton.h"
 #include "ui/widget/uicheckbox.h"
 #include "ui/widget/uitab.h"
 #include "ui/widget/uislider.h"
 #include "ui/widget/uidropdown.h"
 
-#define UI_MENU_LABEL_MAX UI_CHECKBOX_LABEL_MAX
-
 typedef struct uimenu_s uimenu_t;
 
 typedef enum {
@@ -32,7 +31,7 @@ typedef enum {
 typedef struct {
   uimenuwidgettype_t type;
   union {
-    char_t *label;
+    uiwidgetlabel_t label;
     uicheckbox_t checkbox;
     uibutton_t button;
     uitab_t tab;
@@ -178,6 +177,15 @@ uint8_t uiMenuFocusSlotToIndex(const uimenu_t *menu, const uint8_t slot);
  */
 void uiMenuItemSetHighlighted(uimenuitem_t *item, const bool_t highlighted);
 
+/**
+ * Initializes a menu item as a standalone label, caching its text.
+ * Used internally by the MENU_LABEL helper macro.
+ *
+ * @param item The item to initialize.
+ * @param text Display text.
+ */
+void uiMenuLabelInit(uimenuitem_t *item, const char_t *text);
+
 /**
  * Internal focus callback  -  forwards selection to the menu's selected handler.
  *
@@ -227,7 +235,7 @@ bool_t uiMenuFocusDirection(
 #define MENU_LABEL(text) \
   assertTrue(menuIndex < menuCapacity, "Menu item count exceeds capacity"); \
   menu->items[menuIndex].type = UI_MENU_WIDGET_TYPE_LABEL; \
-  menu->items[menuIndex].label = text; \
+  uiMenuLabelInit(&menu->items[menuIndex], text); \
   ++menuIndex
 
 #define MENU_SPACER() \

archive/dusk/ui/widget/uislider.c

@@ -30,13 +30,16 @@ void uiSliderInitFloat(
   assertTrue(step > 0.0f, "Slider step must be greater than zero");
 
   memoryZero(slider, sizeof(uislider_t));
-  slider->label = label;
+  uiWidgetLabelInit(&slider->label, &FONT_DEFAULT);
+  uiWidgetLabelSetText(&slider->label, label);
+  uiWidgetLabelInit(&slider->valueLabel, &FONT_DEFAULT);
   slider->type = UI_SLIDER_TYPE_FLOAT;
   slider->min.f = min;
   slider->max.f = max;
   slider->step.f = step;
   slider->value.f = mathClamp(value, min, max);
-  textMeasure(label, &FONT_DEFAULT, &slider->labelWidth, &slider->labelHeight);
+  uiSliderRebuildValueLabel(slider);
+  uiSliderRebuildGeometry(slider);
 }
 
 void uiSliderInitInt(
@@ -53,13 +56,16 @@ void uiSliderInitInt(
   assertTrue(step > 0, "Slider step must be greater than zero");
 
   memoryZero(slider, sizeof(uislider_t));
-  slider->label = label;
+  uiWidgetLabelInit(&slider->label, &FONT_DEFAULT);
+  uiWidgetLabelSetText(&slider->label, label);
+  uiWidgetLabelInit(&slider->valueLabel, &FONT_DEFAULT);
   slider->type = UI_SLIDER_TYPE_INT;
   slider->min.i = min;
   slider->max.i = max;
   slider->step.i = step;
   slider->value.i = mathClamp(value, min, max);
-  textMeasure(label, &FONT_DEFAULT, &slider->labelWidth, &slider->labelHeight);
+  uiSliderRebuildValueLabel(slider);
+  uiSliderRebuildGeometry(slider);
 }
 
 float_t uiSliderGetFloat(const uislider_t *slider) {
@@ -82,6 +88,8 @@ void uiSliderSetFloat(uislider_t *slider, const float_t value) {
     slider->type == UI_SLIDER_TYPE_FLOAT, "Slider is not a float slider"
   );
   slider->value.f = mathClamp(value, slider->min.f, slider->max.f);
+  uiSliderRebuildValueLabel(slider);
+  uiSliderRebuildGeometry(slider);
 }
 
 void uiSliderSetInt(uislider_t *slider, const int32_t value) {
@@ -90,6 +98,8 @@ void uiSliderSetInt(uislider_t *slider, const int32_t value) {
     slider->type == UI_SLIDER_TYPE_INT, "Slider is not an int slider"
   );
   slider->value.i = mathClamp(value, slider->min.i, slider->max.i);
+  uiSliderRebuildValueLabel(slider);
+  uiSliderRebuildGeometry(slider);
 }
 
 void uiSliderStepUp(uislider_t *slider) {
@@ -140,6 +150,9 @@ bool_t uiSliderIsHighlighted(const uislider_t *slider) {
 void uiSliderSetHighlighted(uislider_t *slider, const bool_t highlighted) {
   assertNotNull(slider, "Slider cannot be NULL");
   slider->highlighted = highlighted;
+  color_t color = highlighted ? COLOR_RED : COLOR_WHITE;
+  uiWidgetLabelSetColor(&slider->label, color);
+  uiWidgetLabelSetColor(&slider->valueLabel, color);
 }
 
 errorret_t uiSliderDraw(
@@ -149,42 +162,97 @@ errorret_t uiSliderDraw(
 ) {
   assertNotNull(slider, "Slider cannot be NULL");
 
-  color_t color = slider->highlighted ? COLOR_RED : COLOR_WHITE;
+  errorChain(uiWidgetLabelDraw(&slider->label, x, y));
 
-  errorChain(textDraw(x, y, slider->label, color, &FONT_DEFAULT));
-
-  float_t trackX = x + (float_t)slider->labelWidth + UI_SLIDER_GAP;
-  float_t trackY = y + ((float_t)slider->labelHeight - UI_SLIDER_TRACK_HEIGHT) * 0.5f;
-
-  spritebatchsprite_t trackSprite = {
-    .min = { trackX, trackY, 0.0f },
-    .max = { trackX + UI_SLIDER_TRACK_WIDTH, trackY + UI_SLIDER_TRACK_HEIGHT, 0.0f },
-    .uvMin = { 0.0f, 0.0f },
-    .uvMax = { 1.0f, 1.0f }
-  };
   shadermaterial_t trackMaterial = {
     .unlit = {
       .color = COLOR_DARK_GRAY,
       .texture = &TEXTURE_WHITE
     }
   };
-  errorChain(spriteBatchBuffer(&trackSprite, 1, &SHADER_UNLIT, trackMaterial));
+  spritebatchsprite_t track = spriteBatchSpriteTranslate(
+    &slider->cachedTrack, x, y
+  );
+  errorChain(spriteBatchBuffer(&track, 1, &SHADER_UNLIT, trackMaterial));
+
+  if(slider->cachedFillVisible) {
+    shadermaterial_t fillMaterial = {
+      .unlit = {
+        .color = slider->highlighted ? COLOR_RED : COLOR_WHITE,
+        .texture = &TEXTURE_WHITE
+      }
+    };
+    spritebatchsprite_t fill = spriteBatchSpriteTranslate(
+      &slider->cachedFill, x, y
+    );
+    errorChain(spriteBatchBuffer(&fill, 1, &SHADER_UNLIT, fillMaterial));
+  }
+
+  if(slider->cachedMarkerCount > 0) {
+    spritebatchsprite_t markers[UI_SLIDER_STEP_MARKERS_MAX];
+    for(int32_t i = 0; i < slider->cachedMarkerCount; i++) {
+      markers[i] = spriteBatchSpriteTranslate(&slider->cachedMarkers[i], x, y);
+    }
+
+    shadermaterial_t markerMaterial = {
+      .unlit = {
+        .color = COLOR_WHITE,
+        .texture = &TEXTURE_WHITE
+      }
+    };
+    errorChain(spriteBatchBuffer(
+      markers, slider->cachedMarkerCount, &SHADER_UNLIT, markerMaterial
+    ));
+  }
+
+  errorChain(uiWidgetLabelDraw(
+    &slider->valueLabel,
+    x + slider->cachedTrack.max[0] + UI_SLIDER_GAP,
+    y
+  ));
+
+  errorOk();
+}
+
+void uiSliderRebuildValueLabel(uislider_t *slider) {
+  char_t valueText[UI_WIDGET_LABEL_TEXT_MAX];
+  if(slider->type == UI_SLIDER_TYPE_INT) {
+    stringFormat(
+      valueText, UI_WIDGET_LABEL_TEXT_MAX - 1, "%d", slider->value.i
+    );
+  } else {
+    stringFormat(
+      valueText, UI_WIDGET_LABEL_TEXT_MAX - 1, "%.2f", slider->value.f
+    );
+  }
+  uiWidgetLabelSetText(&slider->valueLabel, valueText);
+}
+
+void uiSliderRebuildGeometry(uislider_t *slider) {
+  int32_t labelW, labelH;
+  uiWidgetLabelGetSize(&slider->label, &labelW, &labelH);
+
+  float_t trackX = (float_t)labelW + UI_SLIDER_GAP;
+  float_t trackY = ((float_t)labelH - UI_SLIDER_TRACK_HEIGHT) * 0.5f;
+
+  slider->cachedTrack = (spritebatchsprite_t){
+    .min = { trackX, trackY, 0.0f },
+    .max = {
+      trackX + UI_SLIDER_TRACK_WIDTH, trackY + UI_SLIDER_TRACK_HEIGHT, 0.0f
+    },
+    .uvMin = { 0.0f, 0.0f },
+    .uvMax = { 1.0f, 1.0f }
+  };
 
   float_t fillWidth = UI_SLIDER_TRACK_WIDTH * uiSliderGetRatio(slider);
-  if(fillWidth > 0.0f) {
-    spritebatchsprite_t fillSprite = {
+  slider->cachedFillVisible = fillWidth > 0.0f;
+  if(slider->cachedFillVisible) {
+    slider->cachedFill = (spritebatchsprite_t){
       .min = { trackX, trackY, 0.0f },
       .max = { trackX + fillWidth, trackY + UI_SLIDER_TRACK_HEIGHT, 0.0f },
       .uvMin = { 0.0f, 0.0f },
       .uvMax = { 1.0f, 1.0f }
     };
-    shadermaterial_t fillMaterial = {
-      .unlit = {
-        .color = color,
-        .texture = &TEXTURE_WHITE
-      }
-    };
-    errorChain(spriteBatchBuffer(&fillSprite, 1, &SHADER_UNLIT, fillMaterial));
   }
 
   int32_t stepCount = uiSliderGetStepCount(slider);
@@ -192,7 +260,7 @@ errorret_t uiSliderDraw(
     for(int32_t i = 0; i <= stepCount; i++) {
       float_t markerX = trackX +
         UI_SLIDER_TRACK_WIDTH * (float_t)i / (float_t)stepCount;
-      spritebatchsprite_t markerSprite = {
+      slider->cachedMarkers[i] = (spritebatchsprite_t){
         .min = {
           markerX - UI_SLIDER_STEP_MARKER_WIDTH * 0.5f,
           trackY - UI_SLIDER_STEP_MARKER_OVERHANG,
@@ -206,33 +274,9 @@ errorret_t uiSliderDraw(
         .uvMin = { 0.0f, 0.0f },
         .uvMax = { 1.0f, 1.0f }
       };
-      shadermaterial_t markerMaterial = {
-        .unlit = {
-          .color = COLOR_WHITE,
-          .texture = &TEXTURE_WHITE
-        }
-      };
-      errorChain(
-        spriteBatchBuffer(&markerSprite, 1, &SHADER_UNLIT, markerMaterial)
-      );
     }
-  }
-
-  char_t valueText[UI_SLIDER_VALUE_TEXT_MAX];
-  if(slider->type == UI_SLIDER_TYPE_INT) {
-    stringFormat(
-      valueText, UI_SLIDER_VALUE_TEXT_MAX - 1, "%d", slider->value.i
-    );
+    slider->cachedMarkerCount = stepCount + 1;
   } else {
-    stringFormat(
-      valueText, UI_SLIDER_VALUE_TEXT_MAX - 1, "%.2f", slider->value.f
-    );
+    slider->cachedMarkerCount = 0;
   }
-
-  errorChain(textDraw(
-    trackX + UI_SLIDER_TRACK_WIDTH + UI_SLIDER_GAP, y,
-    valueText, color, &FONT_DEFAULT
-  ));
-
-  errorOk();
 }

archive/dusk/ui/widget/uislider.h

@@ -7,13 +7,14 @@
 
 #pragma once
 #include "error/error.h"
+#include "ui/widget/uiwidgetlabel.h"
+#include "display/spritebatch/spritebatchsprite.h"
 
 #define UI_SLIDER_TRACK_WIDTH 80.0f
 #define UI_SLIDER_TRACK_HEIGHT 4.0f
 #define UI_SLIDER_STEP_MARKER_WIDTH 2.0f
 #define UI_SLIDER_STEP_MARKER_OVERHANG 1.0f
 #define UI_SLIDER_GAP 4.0f
-#define UI_SLIDER_VALUE_TEXT_MAX 16
 
 /**
  * Number of discrete steps below which an int slider renders individual
@@ -34,15 +35,24 @@ typedef union {
 } uislidervalue_t;
 
 typedef struct {
-  const char_t *label;
+  uiwidgetlabel_t label;
+  uiwidgetlabel_t valueLabel;
   uislidertype_t type;
   uislidervalue_t value;
   uislidervalue_t min;
   uislidervalue_t max;
   uislidervalue_t step;
   bool_t highlighted;
-  int32_t labelWidth;
-  int32_t labelHeight;
+
+  // Track/fill/marker geometry, cached relative to origin (0,0) and only
+  // rebuilt when the value or step configuration changes (see
+  // uiSliderRebuildGeometry) -- uiSliderDraw just translates these into
+  // position instead of re-deriving them every frame.
+  spritebatchsprite_t cachedTrack;
+  spritebatchsprite_t cachedFill;
+  bool_t cachedFillVisible;
+  spritebatchsprite_t cachedMarkers[UI_SLIDER_STEP_MARKERS_MAX];
+  int32_t cachedMarkerCount;
 } uislider_t;
 
 /**
@@ -185,3 +195,21 @@ errorret_t uiSliderDraw(
   const float_t x,
   const float_t y
 );
+
+/**
+ * Rebuilds the slider's cached value label from its current value.
+ * Called internally whenever value changes.
+ *
+ * @param slider The slider to update.
+ */
+void uiSliderRebuildValueLabel(uislider_t *slider);
+
+/**
+ * Rebuilds the slider's cached track/fill/marker geometry (relative to
+ * origin (0,0)) from its current label size, value, and step
+ * configuration. Called internally on init and whenever the value
+ * changes -- uiSliderDraw never recomputes this itself.
+ *
+ * @param slider The slider to update.
+ */
+void uiSliderRebuildGeometry(uislider_t *slider);

archive/dusk/ui/widget/uitab.c

@@ -7,7 +7,6 @@
 
 #include "uitab.h"
 #include "assert/assert.h"
-#include "util/memory.h"
 #include "display/text/text.h"
 #include "display/color.h"
 #include "display/spritebatch/spritebatch.h"
@@ -17,9 +16,10 @@
 void uiTabInit(uitab_t *tab, const char_t *label) {
   assertNotNull(tab, "Tab cannot be NULL");
   assertNotNull(label, "Label cannot be NULL");
-  memoryZero(tab, sizeof(uitab_t));
-  tab->label = label;
-  textMeasure(label, &FONT_DEFAULT, &tab->labelWidth, &tab->labelHeight);
+  uiWidgetLabelInit(&tab->label, &FONT_DEFAULT);
+  uiWidgetLabelSetText(&tab->label, label);
+  tab->active = false;
+  uiTabRebuildBackground(tab);
 }
 
 bool_t uiTabIsActive(const uitab_t *tab) {
@@ -39,12 +39,9 @@ errorret_t uiTabDraw(
 ) {
   assertNotNull(tab, "Tab cannot be NULL");
 
-  spritebatchsprite_t sprite = {
-    .min = { x, y, 0.0f },
-    .max = { x + (float_t)tab->labelWidth, y + (float_t)tab->labelHeight, 0.0f },
-    .uvMin = { 0.0f, 0.0f },
-    .uvMax = { 1.0f, 1.0f }
-  };
+  spritebatchsprite_t sprite = spriteBatchSpriteTranslate(
+    &tab->cachedBackground, x, y
+  );
   shadermaterial_t material = {
     .unlit = {
       .color = tab->active ? COLOR_GREEN : COLOR_RED,
@@ -52,9 +49,21 @@ errorret_t uiTabDraw(
     }
   };
   errorChain(spriteBatchBuffer(&sprite, 1, &SHADER_UNLIT, material));
-  errorChain(spriteBatchFlush());
 
-  errorChain(textDraw(x, y, tab->label, COLOR_WHITE, &FONT_DEFAULT));
+  errorChain(uiWidgetLabelDraw(&tab->label, x, y));
 
   errorOk();
 }
+
+void uiTabRebuildBackground(uitab_t *tab) {
+  assertNotNull(tab, "Tab cannot be NULL");
+
+  int32_t labelW, labelH;
+  uiWidgetLabelGetSize(&tab->label, &labelW, &labelH);
+  tab->cachedBackground = (spritebatchsprite_t){
+    .min = { 0.0f, 0.0f, 0.0f },
+    .max = { (float_t)labelW, (float_t)labelH, 0.0f },
+    .uvMin = { 0.0f, 0.0f },
+    .uvMax = { 1.0f, 1.0f }
+  };
+}

archive/dusk/ui/widget/uitab.h

@@ -7,12 +7,17 @@
 
 #pragma once
 #include "error/error.h"
+#include "ui/widget/uiwidgetlabel.h"
+#include "display/spritebatch/spritebatchsprite.h"
 
 typedef struct {
-  const char_t *label;
+  uiwidgetlabel_t label;
   bool_t active;
-  int32_t labelWidth;
-  int32_t labelHeight;
+
+  // Background quad, cached relative to origin (0,0) from the label's
+  // size at init -- uiTabDraw only translates this into position, since
+  // active/inactive only changes the material color, not the geometry.
+  spritebatchsprite_t cachedBackground;
 } uitab_t;
 
 /**
@@ -53,3 +58,13 @@ errorret_t uiTabDraw(
   const float_t x,
   const float_t y
 );
+
+/**
+ * Rebuilds the tab's cached background quad (relative to origin (0,0))
+ * from its current label size. Called internally by uiTabInit -- the
+ * background's geometry never changes afterwards, since the tab has no
+ * API to change its label text.
+ *
+ * @param tab The tab to update.
+ */
+void uiTabRebuildBackground(uitab_t *tab);

archive/dusk/ui/widget/uiwidgetlabel.c

@@ -0,0 +1,66 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uiwidgetlabel.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "util/string.h"
+#include "display/text/text.h"
+
+void uiWidgetLabelInit(uiwidgetlabel_t *label, font_t *font) {
+  assertNotNull(label, "Label cannot be NULL");
+  assertNotNull(font, "Font cannot be NULL");
+
+  memoryZero(label, sizeof(uiwidgetlabel_t));
+  label->font = font;
+  label->color = COLOR_WHITE;
+}
+
+void uiWidgetLabelSetText(uiwidgetlabel_t *label, const char_t *text) {
+  assertNotNull(label, "Label cannot be NULL");
+  assertNotNull(text, "Text cannot be NULL");
+  assertStrLenMax(text, UI_WIDGET_LABEL_TEXT_MAX, "Label text too long");
+
+  stringCopy(label->text, text, UI_WIDGET_LABEL_TEXT_MAX);
+  label->spriteCount = textBuildSpriteCache(
+    label->text, label->font, label->sprites,
+    UI_WIDGET_LABEL_SPRITE_COUNT_MAX, &label->width, &label->height
+  );
+}
+
+void uiWidgetLabelSetColor(uiwidgetlabel_t *label, const color_t color) {
+  assertNotNull(label, "Label cannot be NULL");
+  label->color = color;
+}
+
+void uiWidgetLabelGetSize(
+  const uiwidgetlabel_t *label,
+  int32_t *outWidth,
+  int32_t *outHeight
+) {
+  assertNotNull(label, "Label cannot be NULL");
+  assertNotNull(outWidth, "Output width cannot be NULL");
+  assertNotNull(outHeight, "Output height cannot be NULL");
+  *outWidth = label->width;
+  *outHeight = label->height;
+}
+
+errorret_t uiWidgetLabelDraw(
+  const uiwidgetlabel_t *label,
+  const float_t x,
+  const float_t y
+) {
+  assertNotNull(label, "Label cannot be NULL");
+  if(label->spriteCount == 0) errorOk();
+
+  spritebatchsprite_t scratch[UI_WIDGET_LABEL_SPRITE_COUNT_MAX];
+  errorChain(textDrawSpriteCache(
+    label->sprites, label->spriteCount, scratch, x, y, label->color,
+    label->font->texture
+  ));
+  errorOk();
+}

archive/dusk/ui/widget/uiwidgetlabel.h

@@ -0,0 +1,90 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "display/text/font.h"
+#include "display/spritebatch/spritebatchsprite.h"
+#include "display/color.h"
+
+// A cached, cheap-to-redraw label sized for embedding directly inside
+// small widgets (buttons, checkboxes, sliders, ...) rather than
+// referencing text by pointer and re-deriving glyph geometry every
+// frame. Capacity is intentionally much smaller than uilabel_t's -- it
+// gets embedded by value in every widget instance (and inside
+// uimenuitem_t's union, which is often arrayed), so keeping it small
+// matters on memory-constrained targets. See uilabel_t for the
+// general-purpose, larger-capacity equivalent.
+#define UI_WIDGET_LABEL_TEXT_MAX 64
+#define UI_WIDGET_LABEL_SPRITE_COUNT_MAX UI_WIDGET_LABEL_TEXT_MAX
+
+typedef struct {
+  char_t text[UI_WIDGET_LABEL_TEXT_MAX];
+  color_t color;
+  font_t *font;
+
+  spritebatchsprite_t sprites[UI_WIDGET_LABEL_SPRITE_COUNT_MAX];
+  uint32_t spriteCount;
+  int32_t width;
+  int32_t height;
+} uiwidgetlabel_t;
+
+/**
+ * Initializes a widget label, defaulting to white text and no text set.
+ *
+ * @param label The label to initialize.
+ * @param font Font to use for rendering. Must outlive the label.
+ */
+void uiWidgetLabelInit(uiwidgetlabel_t *label, font_t *font);
+
+/**
+ * Sets the label's text, rebuilding its cached sprites immediately.
+ * Call this whenever the displayed text changes -- uiWidgetLabelDraw
+ * never recomputes it.
+ *
+ * @param label The label to update.
+ * @param text Null-terminated string to display. Must be shorter than
+ * UI_WIDGET_LABEL_TEXT_MAX.
+ */
+void uiWidgetLabelSetText(uiwidgetlabel_t *label, const char_t *text);
+
+/**
+ * Sets the label's tint color. Cheap -- doesn't touch the sprite cache.
+ *
+ * @param label The label to update.
+ * @param color The new tint color.
+ */
+void uiWidgetLabelSetColor(uiwidgetlabel_t *label, const color_t color);
+
+/**
+ * Gets the measured size (in pixels) of the label's current text, cached
+ * from the last uiWidgetLabelSetText call.
+ *
+ * @param label The label to query.
+ * @param outWidth Pointer to store the width.
+ * @param outHeight Pointer to store the height.
+ */
+void uiWidgetLabelGetSize(
+  const uiwidgetlabel_t *label,
+  int32_t *outWidth,
+  int32_t *outHeight
+);
+
+/**
+ * Draws the label's cached sprites at the given screen position in a
+ * single batched buffer call. Does not recompute glyph layout.
+ *
+ * @param label The label to draw.
+ * @param x Screen x position.
+ * @param y Screen y position.
+ * @return Any error that occurs.
+ */
+errorret_t uiWidgetLabelDraw(
+  const uiwidgetlabel_t *label,
+  const float_t x,
+  const float_t y
+);

archive/duskrpg/ui/textbox/CMakeLists.txt

@@ -0,0 +1,10 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    uitextbox.c
+    uitextboxmain.c
+)

archive/duskrpg/ui/textbox/uitextbox.c

@@ -0,0 +1,276 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uitextbox.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+#include "util/string.h"
+#include "time/time.h"
+#include "display/text/text.h"
+#include "display/color.h"
+#include "display/spritebatch/spritebatch.h"
+#include "display/shader/shaderunlit.h"
+#include "ui/frame/uiframe.h"
+
+void uiTextboxInit(
+  uitextbox_t *box,
+  char_t *text,
+  const uint32_t maxLength,
+  uitextboxline_t *lines,
+  const uint32_t linesMax
+) {
+  assertNotNull(box, "Textbox cannot be NULL");
+  assertNotNull(text, "Text buffer cannot be NULL");
+  assertTrue(maxLength >= 1, "maxLength must be at least 1");
+  assertNotNull(lines, "Lines buffer cannot be NULL");
+  assertTrue(linesMax >= 1, "linesMax must be at least 1");
+  memoryZero(box, sizeof(uitextbox_t));
+  box->text = text;
+  box->maxLength = maxLength;
+  box->lines = lines;
+  box->linesMax = linesMax;
+  box->glyphsBuiltForPage = -1;
+}
+
+void uiTextboxSetText(uitextbox_t *box, const char_t *text) {
+  assertNotNull(box, "Textbox cannot be NULL");
+  assertNotNull(text, "Text cannot be NULL");
+  stringCopy(box->text, text, box->maxLength);
+  box->currentPage = 0;
+  box->scroll = 0;
+  box->layoutWidth = 0.0f;
+  box->layoutHeight = 0.0f;
+  box->glyphsBuiltForPage = -1;
+}
+
+void uiTextboxBuildLayout(
+  uitextbox_t *box,
+  const float_t width,
+  const float_t height
+) {
+  assertNotNull(box, "Textbox cannot be NULL");
+
+  box->glyphsBuiltForPage = -1;
+  box->layoutWidth = width;
+  box->layoutHeight = height;
+  box->lineCount = 0;
+  box->pageCount = 1;
+
+  float_t fontW = (float_t)FONT_DEFAULT.tileset->tileWidth;
+  float_t fontH = (float_t)FONT_DEFAULT.tileset->tileHeight;
+
+  if(fontW <= 0.0f || fontH <= 0.0f) return;
+
+  box->charsPerLine = (int32_t)(width / fontW);
+  box->linesPerPage = (int32_t)(height / (fontH + UI_TEXTBOX_LINE_SPACING));
+  if(box->linesPerPage > UI_TEXTBOX_LINES_PER_PAGE_MAX) {
+    box->linesPerPage = UI_TEXTBOX_LINES_PER_PAGE_MAX;
+  }
+
+  if(box->charsPerLine <= 0 || box->linesPerPage <= 0) return;
+  if(box->text[0] == '\0') return;
+
+  char_t *src = box->text;
+  int32_t i = 0;
+
+  while(src[i] != '\0' && box->lineCount < (int32_t)box->linesMax) {
+    if(src[i] == '\t') {
+      i++;
+      int32_t rem = box->lineCount % box->linesPerPage;
+      int32_t pad = rem > 0 ? box->linesPerPage - rem : 0;
+      while(pad > 0 && box->lineCount < (int32_t)box->linesMax) {
+        box->lines[box->lineCount].start = i;
+        box->lines[box->lineCount].count = 0;
+        box->lineCount++;
+        pad--;
+      }
+      continue;
+    }
+
+    int32_t lineStart = i;
+    int32_t lineWidth = 0;
+
+    while(src[i] != '\0') {
+      char_t c = src[i];
+
+      if(c == '\n') { i++; break; }
+      if(c == '\t') break;
+
+      if(c == ' ') {
+        int32_t wordLen = 0;
+        int32_t j = i + 1;
+        while(
+          src[j] != ' ' && src[j] != '\n' &&
+          src[j] != '\t' && src[j] != '\0'
+        ) {
+          wordLen++;
+          j++;
+        }
+
+        if(lineWidth > 0 && lineWidth + 1 + wordLen > box->charsPerLine) {
+          i++;
+          break;
+        }
+
+        lineWidth++;
+        i++;
+      } else {
+        if(lineWidth >= box->charsPerLine) break;
+        lineWidth++;
+        i++;
+      }
+    }
+
+    box->lines[box->lineCount].start = lineStart;
+    box->lines[box->lineCount].count = lineWidth;
+    box->lineCount++;
+  }
+
+  if(box->lineCount == 0) {
+    box->pageCount = 1;
+  } else {
+    box->pageCount =
+      (box->lineCount + box->linesPerPage - 1) / box->linesPerPage;
+  }
+}
+
+errorret_t uiTextboxUpdate(uitextbox_t *box) {
+  assertNotNull(box, "Textbox cannot be NULL");
+
+  #ifdef DUSK_TIME_DYNAMIC
+    if(TIME.dynamicUpdate) errorOk();
+  #endif
+
+  if(!uiTextboxPageIsComplete(box)) {
+    box->scroll += UI_TEXTBOX_SCROLL_CHARS_PER_TICK;
+  }
+
+  errorOk();
+}
+
+errorret_t uiTextboxDraw(
+  uitextbox_t *box,
+  const float_t x,
+  const float_t y,
+  const float_t width,
+  const float_t height
+) {
+  assertNotNull(box, "Textbox cannot be NULL");
+
+  float_t startX = (float_t)UI_FRAME_START_X;
+  float_t startY = (float_t)UI_FRAME_START_Y;
+  float_t contentX = x + startX;
+  float_t contentY = y + startY;
+  float_t contentW = width - 2.0f * startX;
+  float_t contentH = height - 2.0f * startY;
+
+  if(contentW != box->layoutWidth || contentH != box->layoutHeight) {
+    uiTextboxBuildLayout(box, contentW, contentH);
+  }
+
+  errorChain(uiFrameDrawCached(&box->frameCache, x, y, width, height));
+
+  if(box->lineCount == 0 || box->text[0] == '\0') errorOk();
+
+  if(box->glyphsBuiltForPage != box->currentPage) {
+    uiTextboxBuildPageGlyphs(box);
+  }
+
+  if(box->glyphCount == 0) errorOk();
+
+  int32_t visibleCount = 0;
+  while(
+    visibleCount < box->glyphCount &&
+    box->glyphs[visibleCount].revealAt <= box->scroll
+  ) visibleCount++;
+
+  if(visibleCount == 0) errorOk();
+
+  spritebatchsprite_t scratch[UI_TEXTBOX_PAGE_GLYPHS_MAX];
+  for(int32_t i = 0; i < visibleCount; i++) {
+    scratch[i] = spriteBatchSpriteTranslate(
+      &box->glyphs[i].sprite, contentX, contentY
+    );
+  }
+
+  shadermaterial_t material = {
+    .unlit = {
+      .color = COLOR_WHITE,
+      .texture = FONT_DEFAULT.texture
+    }
+  };
+  errorChain(spriteBatchBuffer(scratch, visibleCount, &SHADER_UNLIT, material));
+
+  errorOk();
+}
+
+void uiTextboxBuildPageGlyphs(uitextbox_t *box) {
+  assertNotNull(box, "Textbox cannot be NULL");
+
+  box->glyphCount = 0;
+
+  int32_t pageFirst = box->currentPage * box->linesPerPage;
+  int32_t pageLast = pageFirst + box->linesPerPage;
+  if(pageLast > box->lineCount) pageLast = box->lineCount;
+
+  float_t fontW = (float_t)FONT_DEFAULT.tileset->tileWidth;
+  float_t fontH = (float_t)FONT_DEFAULT.tileset->tileHeight;
+
+  int32_t consumed = 0;
+  for(int32_t li = pageFirst; li < pageLast; li++) {
+    uitextboxline_t *line = &box->lines[li];
+    float_t lineY =
+      (float_t)(li - pageFirst) * (fontH + UI_TEXTBOX_LINE_SPACING);
+
+    for(int32_t ci = 0; ci < line->count; ci++) {
+      consumed++;
+      char_t c = box->text[line->start + ci];
+      if(c == ' ') continue;
+
+      assertTrue(
+        box->glyphCount < UI_TEXTBOX_PAGE_GLYPHS_MAX,
+        "Textbox page produces too many glyphs"
+      );
+      uitextboxglyph_t *glyph = &box->glyphs[box->glyphCount++];
+      glyph->sprite = textGetSprite(
+        (vec2){ (float_t)ci * fontW, lineY }, c, &FONT_DEFAULT
+      );
+      glyph->revealAt = consumed;
+    }
+  }
+
+  box->glyphsBuiltForPage = box->currentPage;
+}
+
+int32_t uiTextboxGetPageCharCount(const uitextbox_t *box) {
+  assertNotNull(box, "Textbox cannot be NULL");
+  int32_t first = box->currentPage * box->linesPerPage;
+  int32_t last = first + box->linesPerPage;
+  if(last > box->lineCount) last = box->lineCount;
+  int32_t total = 0;
+  for(int32_t i = first; i < last; i++) {
+    total += box->lines[i].count;
+  }
+  return total;
+}
+
+bool_t uiTextboxPageIsComplete(const uitextbox_t *box) {
+  assertNotNull(box, "Textbox cannot be NULL");
+  return box->scroll >= uiTextboxGetPageCharCount(box);
+}
+
+bool_t uiTextboxHasNextPage(const uitextbox_t *box) {
+  assertNotNull(box, "Textbox cannot be NULL");
+  return box->currentPage + 1 < box->pageCount;
+}
+
+void uiTextboxNextPage(uitextbox_t *box) {
+  assertNotNull(box, "Textbox cannot be NULL");
+  if(!uiTextboxHasNextPage(box)) return;
+  box->currentPage++;
+  box->scroll = 0;
+}

archive/duskrpg/ui/textbox/uitextbox.h

@@ -0,0 +1,175 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+#include "ui/frame/uiframe.h"
+#include "display/spritebatch/spritebatchsprite.h"
+
+#define UI_TEXTBOX_LINES_PER_PAGE_MAX 4
+#define UI_TEXTBOX_SCROLL_CHARS_PER_TICK 1
+#define UI_TEXTBOX_LINE_SPACING 0.0f
+
+// Fixed capacity for a page's cached glyph sprites (see uitextboxglyph_t).
+// Sized generously above UI_TEXTBOX_LINES_PER_PAGE_MAX worth of glyphs at
+// typical textbox widths; uiTextboxBuildPageGlyphs asserts if a page
+// somehow produces more than this.
+#define UI_TEXTBOX_PAGE_GLYPHS_MAX 512
+
+typedef struct {
+  int32_t start;
+  int32_t count;
+} uitextboxline_t;
+
+// A single visible glyph's cached sprite (relative to the textbox's
+// content origin, i.e. (0,0)) plus the scroll value at/after which it
+// becomes visible -- lets uiTextboxDraw turn the typewriter scroll into
+// a simple prefix-count instead of recomputing glyph geometry every
+// frame.
+typedef struct {
+  spritebatchsprite_t sprite;
+  int32_t revealAt;
+} uitextboxglyph_t;
+
+typedef struct {
+  char_t *text;
+  uint32_t maxLength;
+
+  uitextboxline_t *lines;
+  uint32_t linesMax;
+  int32_t lineCount;
+  int32_t charsPerLine;
+  int32_t linesPerPage;
+  int32_t pageCount;
+
+  // last dimensions used for layout; rebuild triggers when these change
+  float_t layoutWidth;
+  float_t layoutHeight;
+
+  int32_t currentPage;
+  int32_t scroll;
+
+  // Cached glyph sprites for the current page (see uitextboxglyph_t),
+  // rebuilt only when currentPage no longer matches
+  // glyphsBuiltForPage -- not every frame/scroll tick.
+  uitextboxglyph_t glyphs[UI_TEXTBOX_PAGE_GLYPHS_MAX];
+  int32_t glyphCount;
+  int32_t glyphsBuiltForPage;
+
+  uiframecache_t frameCache;
+} uitextbox_t;
+
+/**
+ * Initializes a textbox, zeroing all state and binding it to caller-owned
+ * text and line storage.
+ *
+ * @param box The textbox to initialize.
+ * @param text Caller-owned buffer the textbox copies its text into.
+ * @param maxLength Capacity of text, in characters.
+ * @param lines Caller-owned buffer the textbox lays lines out into.
+ * @param linesMax Capacity of lines, in entries.
+ */
+void uiTextboxInit(
+  uitextbox_t *box,
+  char_t *text,
+  const uint32_t maxLength,
+  uitextboxline_t *lines,
+  const uint32_t linesMax
+);
+
+/**
+ * Copies text into the textbox and marks layout as dirty.
+ * Resets currentPage and scroll to 0.
+ *
+ * @param box The textbox to update.
+ * @param text Null-terminated source string.
+ */
+void uiTextboxSetText(uitextbox_t *box, const char_t *text);
+
+/**
+ * Rebuilds word-wrap and page layout for the given draw dimensions.
+ * Called automatically by uiTextboxDraw when width or height changes.
+ *
+ * @param box The textbox to rebuild.
+ * @param width Available content width in pixels.
+ * @param height Available content height in pixels.
+ */
+void uiTextboxBuildLayout(
+  uitextbox_t *box,
+  const float_t width,
+  const float_t height
+);
+
+/**
+ * Advances the typewriter scroll by UI_TEXTBOX_SCROLL_CHARS_PER_TICK.
+ * Skipped on dynamic ticks.
+ *
+ * @param box The textbox to update.
+ * @returns Any error that occurs.
+ */
+errorret_t uiTextboxUpdate(uitextbox_t *box);
+
+/**
+ * Draws the textbox frame and visible text. Rebuilds layout automatically
+ * if width or height differs from the last draw call.
+ *
+ * @param box The textbox to draw.
+ * @param x Screen x position.
+ * @param y Screen y position.
+ * @param width Draw width in pixels.
+ * @param height Draw height in pixels.
+ * @returns Any error that occurs.
+ */
+errorret_t uiTextboxDraw(
+  uitextbox_t *box,
+  const float_t x,
+  const float_t y,
+  const float_t width,
+  const float_t height
+);
+
+/**
+ * Returns the total visible char count for the current page.
+ *
+ * @param box The textbox to query.
+ * @returns Total chars on the current page.
+ */
+int32_t uiTextboxGetPageCharCount(const uitextbox_t *box);
+
+/**
+ * Returns true when scroll has fully revealed the current page.
+ *
+ * @param box The textbox to query.
+ * @returns True if the current page is fully visible.
+ */
+bool_t uiTextboxPageIsComplete(const uitextbox_t *box);
+
+/**
+ * Returns true when there is at least one more page after the current one.
+ *
+ * @param box The textbox to query.
+ * @returns True if a next page exists.
+ */
+bool_t uiTextboxHasNextPage(const uitextbox_t *box);
+
+/**
+ * Advances to the next page and resets scroll to 0.
+ * Has no effect if already on the last page.
+ *
+ * @param box The textbox to advance.
+ */
+void uiTextboxNextPage(uitextbox_t *box);
+
+/**
+ * Rebuilds the cached glyph sprites (see uitextboxglyph_t) for the
+ * current page from its line layout. Called automatically by
+ * uiTextboxDraw whenever currentPage no longer matches the page the
+ * cache was last built for.
+ *
+ * @param box The textbox to rebuild.
+ */
+void uiTextboxBuildPageGlyphs(uitextbox_t *box);

archive/duskrpg/ui/textbox/uitextboxmain.c

@@ -0,0 +1,121 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uitextboxmain.h"
+#include "ui/focus/uifocus.h"
+#include "display/screen/screen.h"
+#include "display/text/text.h"
+#include "display/color.h"
+#include "display/spritebatch/spritebatch.h"
+#include "display/shader/shaderunlit.h"
+#include "ui/frame/uiframe.h"
+
+uitextboxmain_t UI_TEXTBOX_MAIN;
+static uifocusitem_t *focusItem = NULL;
+
+errorret_t uiTextboxMainInit(void) {
+  uiTextboxInit(
+    &UI_TEXTBOX_MAIN.box,
+    UI_TEXTBOX_MAIN.text, UI_TEXTBOX_MAIN_TEXT_MAX,
+    UI_TEXTBOX_MAIN.lines, UI_TEXTBOX_MAIN_LINES_MAX
+  );
+  errorOk();
+}
+
+void uiTextboxMainSetText(const char_t *text) {
+  uiTextboxSetText(&UI_TEXTBOX_MAIN.box, text);
+  if(focusItem != NULL) return;
+  focusItem = uiFocusPush(
+    1, 1,
+    uiTextboxMainFocusSelected,
+    NULL,
+    uiTextboxMainFocusClosed,
+    NULL,
+    NULL
+  );
+}
+
+errorret_t uiTextboxMainUpdate(void) {
+  if(focusItem == NULL) errorOk();
+  return uiTextboxUpdate(&UI_TEXTBOX_MAIN.box);
+}
+
+errorret_t uiTextboxMainDraw(void) {
+  if(focusItem == NULL) errorOk();
+  float_t fontH = (float_t)FONT_DEFAULT.tileset->tileHeight;
+  float_t h = (float_t)UI_TEXTBOX_MAIN_LINES * fontH +
+    (float_t)(UI_TEXTBOX_MAIN_LINES - 1) * UI_TEXTBOX_LINE_SPACING +
+    2.0f * (float_t)UI_FRAME_START_Y;
+  float_t w = (float_t)SCREEN.scanWidth;
+  float_t x = (float_t)SCREEN.scanX;
+  float_t y = (float_t)(SCREEN.scanY + SCREEN.scanHeight) - h;
+  errorChain(uiTextboxDraw(&UI_TEXTBOX_MAIN.box, x, y, w, h));
+
+  if(!uiTextboxPageIsComplete(&UI_TEXTBOX_MAIN.box)) errorOk();
+
+  float_t fontW = (float_t)FONT_DEFAULT.tileset->tileWidth;
+  float_t contentX = x + (float_t)UI_FRAME_START_X;
+  float_t contentY = y + (float_t)UI_FRAME_START_Y;
+  float_t contentW = w - 2.0f * (float_t)UI_FRAME_START_X;
+  float_t contentH = h - 2.0f * (float_t)UI_FRAME_START_Y;
+
+  shadermaterial_t material = {
+    .unlit = {
+      .color = COLOR_WHITE,
+      .texture = FONT_DEFAULT.texture
+    }
+  };
+
+  spritebatchsprite_t caret = textGetSprite(
+    (vec2){
+      contentX + contentW - fontW,
+      contentY + contentH - fontH
+    },
+    'v',
+    &FONT_DEFAULT
+  );
+  errorChain(spriteBatchBuffer(&caret, 1, &SHADER_UNLIT, material));
+
+  errorOk();
+}
+
+bool_t uiTextboxMainPageIsComplete(void) {
+  return uiTextboxPageIsComplete(&UI_TEXTBOX_MAIN.box);
+}
+
+bool_t uiTextboxMainHasNextPage(void) {
+  return uiTextboxHasNextPage(&UI_TEXTBOX_MAIN.box);
+}
+
+void uiTextboxMainNextPage(void) {
+  uiTextboxNextPage(&UI_TEXTBOX_MAIN.box);
+}
+
+bool_t uiTextboxMainIsActive(void) {
+  return focusItem != NULL;
+}
+
+bool_t uiTextboxMainFocusSelected(const uifocusitem_t *item) {
+  if(!uiTextboxPageIsComplete(&UI_TEXTBOX_MAIN.box)) {
+    UI_TEXTBOX_MAIN.box.scroll =
+      uiTextboxGetPageCharCount(&UI_TEXTBOX_MAIN.box);
+    return true;
+  }
+
+  if(uiTextboxHasNextPage(&UI_TEXTBOX_MAIN.box)) {
+    uiTextboxNextPage(&UI_TEXTBOX_MAIN.box);
+    return true;
+  }
+
+  uiFocusPopItem(focusItem);
+  return true;
+}
+
+bool_t uiTextboxMainFocusClosed(const uifocusitem_t *item) {
+  focusItem = NULL;
+  return true;
+}

archive/duskrpg/ui/textbox/uitextboxmain.h

@@ -0,0 +1,94 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "uitextbox.h"
+#include "ui/focus/uifocusitem.h"
+
+#define UI_TEXTBOX_MAIN_LINES 4
+#define UI_TEXTBOX_MAIN_TEXT_MAX 1024
+#define UI_TEXTBOX_MAIN_LINES_MAX 64
+
+typedef struct {
+  uitextbox_t box;
+  char_t text[UI_TEXTBOX_MAIN_TEXT_MAX];
+  uitextboxline_t lines[UI_TEXTBOX_MAIN_LINES_MAX];
+} uitextboxmain_t;
+
+extern uitextboxmain_t UI_TEXTBOX_MAIN;
+
+/**
+ * Initializes UI_TEXTBOX_MAIN.
+ *
+ * @returns Any error that occurs.
+ */
+errorret_t uiTextboxMainInit(void);
+
+/**
+ * Copies text into UI_TEXTBOX_MAIN and resets page and scroll.
+ *
+ * @param text Null-terminated source string.
+ */
+void uiTextboxMainSetText(const char_t *text);
+
+/**
+ * Advances the typewriter scroll for UI_TEXTBOX_MAIN.
+ *
+ * @returns Any error that occurs.
+ */
+errorret_t uiTextboxMainUpdate(void);
+
+/**
+ * Draws UI_TEXTBOX_MAIN full-width at the bottom of the screen.
+ * Position and size are derived from SCREEN each call.
+ *
+ * @returns Any error that occurs.
+ */
+errorret_t uiTextboxMainDraw(void);
+
+/**
+ * Returns true when the current page is fully scrolled in.
+ *
+ * @returns True if the current page is complete.
+ */
+bool_t uiTextboxMainPageIsComplete(void);
+
+/**
+ * Returns true when at least one more page follows the current one.
+ *
+ * @returns True if a next page exists.
+ */
+bool_t uiTextboxMainHasNextPage(void);
+
+/**
+ * Advances UI_TEXTBOX_MAIN to the next page and resets scroll.
+ * Has no effect if already on the last page.
+ */
+void uiTextboxMainNextPage(void);
+
+/**
+ * Returns true when UI_TEXTBOX_MAIN has focus (is visible and active).
+ *
+ * @returns True if the textbox is currently active.
+ */
+bool_t uiTextboxMainIsActive(void);
+
+/**
+ * Internal focus callback - skip scroll or advance page or dismiss.
+ *
+ * @param item The active focus item.
+ * @returns True.
+ */
+bool_t uiTextboxMainFocusSelected(const uifocusitem_t *item);
+
+/**
+ * Internal focus callback - clears the focus item pointer on dismiss.
+ *
+ * @param item The focus item being closed.
+ * @returns True.
+ */
+bool_t uiTextboxMainFocusClosed(const uifocusitem_t *item);

archive/duskrpg/ui/uitestlabel.c

@@ -0,0 +1,35 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "uitestlabel.h"
+#include "ui/widget/uilabel.h"
+#include "display/text/text.h"
+#include "display/screen/screen.h"
+#include "engine/engine.h"
+
+uilabel_t UI_TEST_LABEL;
+
+errorret_t uiTestLabelInit() {
+  uiLabelInit(&UI_TEST_LABEL, &FONT_DEFAULT);
+  uiLabelSetText(&UI_TEST_LABEL, "duskrpg");
+  errorOk();
+}
+
+errorret_t uiTestLabelDraw() {
+  int32_t versionWidth, versionHeight;
+  textMeasure(ENGINE.version, &FONT_DEFAULT, &versionWidth, &versionHeight);
+
+  errorChain(uiLabelDraw(
+    &UI_TEST_LABEL,
+    (float_t)(SCREEN.scanX + SCREEN.scanWidth - UI_TEST_LABEL.width),
+    (float_t)(
+      SCREEN.scanY + SCREEN.scanHeight - versionHeight -
+      UI_TEST_LABEL.height
+    )
+  ));
+  errorOk();
+}

archive/duskrpg/ui/uitestlabel.h

@@ -0,0 +1,24 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+
+/**
+ * Initializes the test label, a smoke test for the duskrpg-side UI
+ * element extension point (uielementgame.h).
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiTestLabelInit();
+
+/**
+ * Draws the test label above the engine's debug version number.
+ *
+ * @return Any error that occurs.
+ */
+errorret_t uiTestLabelDraw();

archive/test/ui/CMakeLists.txt

@@ -0,0 +1,11 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+include(dusktest)
+
+# Tests
+dusktest(test_uiframe.c)
+dusktest(test_uislider.c)
+dusktest(test_uitab.c)

archive/test/ui/test_uiframe.c

@@ -0,0 +1,68 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "dusktest.h"
+#include "ui/frame/uiframe.h"
+
+static void test_uiFrameBuildSprites_layout(void **state) {
+  UI_FRAME.tileset = (tileset_t){
+    .tileWidth = 1,
+    .tileHeight = 1,
+    .tileCount = 9,
+    .columns = 3,
+    .rows = 3,
+    .uv = { 0.25f, 0.25f }
+  };
+
+  const float_t x = 100.0f;
+  const float_t y = 50.0f;
+  const float_t width = 40.0f;
+  const float_t height = 30.0f;
+  const float_t tileW = (float_t)UI_FRAME_BORDER_WIDTH;
+  const float_t tileH = (float_t)UI_FRAME_BORDER_HEIGHT;
+
+  spritebatchsprite_t sprites[9];
+  uiFrameBuildSprites(sprites, x, y, width, height);
+
+  // Top-left corner sits exactly at the rect's origin.
+  assert_float_equal(sprites[0].min[0], x, 0.0001f);
+  assert_float_equal(sprites[0].min[1], y, 0.0001f);
+  assert_float_equal(sprites[0].max[0], x + tileW, 0.0001f);
+  assert_float_equal(sprites[0].max[1], y + tileH, 0.0001f);
+  assert_float_equal(sprites[0].uvMin[0], 0.0f, 0.0001f);
+  assert_float_equal(sprites[0].uvMin[1], 0.0f, 0.0001f);
+  assert_float_equal(sprites[0].uvMax[0], 0.25f, 0.0001f);
+  assert_float_equal(sprites[0].uvMax[1], 0.25f, 0.0001f);
+
+  // Top-middle edge stretches to fill the width minus both corners.
+  assert_float_equal(sprites[1].min[0], x + tileW, 0.0001f);
+  assert_float_equal(sprites[1].max[0], x + width - tileW, 0.0001f);
+  assert_float_equal(sprites[1].max[1], y + tileH, 0.0001f);
+
+  // Center tile fills the remaining interior on both axes.
+  assert_float_equal(sprites[4].min[0], x + tileW, 0.0001f);
+  assert_float_equal(sprites[4].min[1], y + tileH, 0.0001f);
+  assert_float_equal(sprites[4].max[0], x + width - tileW, 0.0001f);
+  assert_float_equal(sprites[4].max[1], y + height - tileH, 0.0001f);
+
+  // Bottom-right corner sits exactly at the rect's far corner, sampling
+  // tileset column 2, row 2.
+  assert_float_equal(sprites[8].min[0], x + width - tileW, 0.0001f);
+  assert_float_equal(sprites[8].min[1], y + height - tileH, 0.0001f);
+  assert_float_equal(sprites[8].max[0], x + width, 0.0001f);
+  assert_float_equal(sprites[8].max[1], y + height, 0.0001f);
+  assert_float_equal(sprites[8].uvMin[0], 0.5f, 0.0001f);
+  assert_float_equal(sprites[8].uvMin[1], 0.5f, 0.0001f);
+}
+
+int main(int argc, char **argv) {
+  const struct CMUnitTest tests[] = {
+    cmocka_unit_test(test_uiFrameBuildSprites_layout),
+  };
+
+  return cmocka_run_group_tests(tests, NULL, NULL);
+}

archive/test/ui/test_uislider.c

@@ -0,0 +1,114 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "dusktest.h"
+#include "ui/widget/uislider.h"
+#include "util/memory.h"
+
+// uiSliderInitFloat/InitInt require a real font (FONT_DEFAULT) to build
+// the label's glyph cache, which needs a live GL context this test binary
+// doesn't have -- see the label size caching contract for why this is
+// safe to bypass here (uiSliderRebuildGeometry only reads slider->label's
+// already-measured width/height, it never touches the font itself).
+static void sliderSetupFloat(
+  uislider_t *slider,
+  const float_t value,
+  const float_t min,
+  const float_t max,
+  const float_t step
+) {
+  memoryZero(slider, sizeof(uislider_t));
+  slider->label.width = 20;
+  slider->label.height = 10;
+  slider->type = UI_SLIDER_TYPE_FLOAT;
+  slider->min.f = min;
+  slider->max.f = max;
+  slider->step.f = step;
+  slider->value.f = value;
+}
+
+static void sliderSetupInt(
+  uislider_t *slider,
+  const int32_t value,
+  const int32_t min,
+  const int32_t max,
+  const int32_t step
+) {
+  memoryZero(slider, sizeof(uislider_t));
+  slider->label.width = 20;
+  slider->label.height = 10;
+  slider->type = UI_SLIDER_TYPE_INT;
+  slider->min.i = min;
+  slider->max.i = max;
+  slider->step.i = step;
+  slider->value.i = value;
+}
+
+static void test_uiSliderRebuildGeometry_trackPosition(void **state) {
+  uislider_t slider;
+  sliderSetupFloat(&slider, 0.0f, 0.0f, 1.0f, 0.1f);
+  uiSliderRebuildGeometry(&slider);
+
+  const float_t expectedX = (float_t)slider.label.width + UI_SLIDER_GAP;
+  const float_t expectedY =
+    ((float_t)slider.label.height - UI_SLIDER_TRACK_HEIGHT) * 0.5f;
+
+  assert_float_equal(slider.cachedTrack.min[0], expectedX, 0.0001f);
+  assert_float_equal(slider.cachedTrack.min[1], expectedY, 0.0001f);
+  assert_float_equal(
+    slider.cachedTrack.max[0], expectedX + UI_SLIDER_TRACK_WIDTH, 0.0001f
+  );
+}
+
+static void test_uiSliderRebuildGeometry_fillVisibility(void **state) {
+  uislider_t slider;
+
+  // At the minimum value, the ratio is 0 -- no fill should be visible.
+  sliderSetupFloat(&slider, 0.0f, 0.0f, 10.0f, 1.0f);
+  uiSliderRebuildGeometry(&slider);
+  assert_false(slider.cachedFillVisible);
+
+  // Halfway to max -- fill should cover half the track.
+  sliderSetupFloat(&slider, 5.0f, 0.0f, 10.0f, 1.0f);
+  uiSliderRebuildGeometry(&slider);
+  assert_true(slider.cachedFillVisible);
+  assert_float_equal(
+    slider.cachedFill.max[0] - slider.cachedFill.min[0],
+    UI_SLIDER_TRACK_WIDTH * 0.5f,
+    0.0001f
+  );
+}
+
+static void test_uiSliderRebuildGeometry_stepMarkers(void **state) {
+  uislider_t slider;
+
+  // 5 steps between 0 and 10 -- under the marker cap, so markers render.
+  sliderSetupInt(&slider, 0, 0, 10, 2);
+  uiSliderRebuildGeometry(&slider);
+  assert_int_equal(slider.cachedMarkerCount, 6);
+  assert_float_equal(
+    slider.cachedMarkers[0].min[0], slider.cachedTrack.min[0] -
+      UI_SLIDER_STEP_MARKER_WIDTH * 0.5f,
+    0.0001f
+  );
+
+  // 100 steps -- over the marker cap, so it falls back to a smooth fill
+  // with no markers.
+  sliderSetupInt(&slider, 0, 0, 100, 1);
+  uiSliderRebuildGeometry(&slider);
+  assert_int_equal(slider.cachedMarkerCount, 0);
+}
+
+int main(int argc, char **argv) {
+  const struct CMUnitTest tests[] = {
+    cmocka_unit_test(test_uiSliderRebuildGeometry_trackPosition),
+    cmocka_unit_test(test_uiSliderRebuildGeometry_fillVisibility),
+    cmocka_unit_test(test_uiSliderRebuildGeometry_stepMarkers),
+  };
+
+  return cmocka_run_group_tests(tests, NULL, NULL);
+}

archive/test/ui/test_uitab.c

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "dusktest.h"
+#include "ui/widget/uitab.h"
+#include "util/memory.h"
+
+// uiTabInit requires a real font (FONT_DEFAULT) to build the label's
+// glyph cache, which needs a live GL context this test binary doesn't
+// have. uiTabRebuildBackground only reads the label's already-measured
+// width/height, so it's safe to set those directly and exercise it here.
+static void test_uiTabRebuildBackground_matchesLabelSize(void **state) {
+  uitab_t tab;
+  memoryZero(&tab, sizeof(uitab_t));
+  tab.label.width = 42;
+  tab.label.height = 12;
+
+  uiTabRebuildBackground(&tab);
+
+  assert_float_equal(tab.cachedBackground.min[0], 0.0f, 0.0001f);
+  assert_float_equal(tab.cachedBackground.min[1], 0.0f, 0.0001f);
+  assert_float_equal(tab.cachedBackground.max[0], 42.0f, 0.0001f);
+  assert_float_equal(tab.cachedBackground.max[1], 12.0f, 0.0001f);
+}
+
+int main(int argc, char **argv) {
+  const struct CMUnitTest tests[] = {
+    cmocka_unit_test(test_uiTabRebuildBackground_matchesLabelSize),
+  };
+
+  return cmocka_run_group_tests(tests, NULL, NULL);
+}

assets/engine.js

@@ -1,47 +0,0 @@
-var Actions;
-var camera, cameraPosition;
-var cube, cubePosition, cubeRenderable, cubeMesh;
-var ground, groundPosition, groundRenderable;
-
-// init() is called via scriptManagerCallGlobal(), which pumps the asset
-// system + job queue until any promise it returns settles - so it's safe
-// to await include() here even though this runs before the main loop.
-async function init() {
-  Actions = await include("input.js");
-
-  camera = new Entity();
-  cameraPosition = camera.add(POSITION);
-  camera.add(CAMERA);
-  cameraPosition.position = new Vec3(3, 3, -6);
-  cameraPosition.lookAt(new Vec3(0, 0, 0));
-
-  cube = new Entity();
-  cubePosition = cube.add(POSITION);
-  cubeRenderable = cube.add(RENDERABLE);
-  cubeMesh = Mesh.createCube();
-  cubeRenderable.mesh = cubeMesh;
-  cubeRenderable.color = Color.red();
-
-  ground = new Entity();
-  groundPosition = ground.add(POSITION);
-  groundRenderable = ground.add(RENDERABLE);
-  groundRenderable.mesh = Mesh.createCube();
-  groundRenderable.color = Color.dark_gray();
-}
-
-// Runs every frame (including dynamic/interpolation frames) - use for
-// smooth, purely presentational animation.
-function update() {
-  cubePosition.rotation.y += TIME.delta * 1.5;
-  cubePosition.rotation.x += TIME.delta * 0.7;
-}
-
-// Runs once per fixed timestep only - use for gameplay logic that should
-// be deterministic and independent of display refresh rate.
-function fixedUpdate() {
-}
-
-function deinit() {
-  cube.dispose();
-  camera.dispose();
-}

assets/input.js

@@ -1,27 +0,0 @@
-// Binds physical buttons to abstract actions, then exports the action
-// constants so other scripts don't need to know raw INPUT_ACTION_* names.
-Input.bind("w", INPUT_ACTION_UP);
-Input.bind("s", INPUT_ACTION_DOWN);
-Input.bind("a", INPUT_ACTION_LEFT);
-Input.bind("d", INPUT_ACTION_RIGHT);
-Input.bind("space", INPUT_ACTION_ACCEPT);
-Input.bind("escape", INPUT_ACTION_RAGEQUIT);
-
-if(typeof INPUT_GAMEPAD !== "undefined") {
-  Input.bind("gamepad_up", INPUT_ACTION_UP);
-  Input.bind("gamepad_down", INPUT_ACTION_DOWN);
-  Input.bind("gamepad_left", INPUT_ACTION_LEFT);
-  Input.bind("gamepad_right", INPUT_ACTION_RIGHT);
-  Input.bind("gamepad_a", INPUT_ACTION_ACCEPT);
-  Input.bind("gamepad_start", INPUT_ACTION_RAGEQUIT);
-}
-
-module = {
-  UP: INPUT_ACTION_UP,
-  DOWN: INPUT_ACTION_DOWN,
-  LEFT: INPUT_ACTION_LEFT,
-  RIGHT: INPUT_ACTION_RIGHT,
-  ACCEPT: INPUT_ACTION_ACCEPT,
-  CANCEL: INPUT_ACTION_CANCEL,
-  RAGEQUIT: INPUT_ACTION_RAGEQUIT
-};

assets/locale/en_US.po

@@ -1,2 +1,66 @@
-msgid "test.string"
-msgstr "This is a test string"
+msgid ""
+msgstr ""
+"Project-Id-Version: ExampleApp 1.0\n"
+"Language: en\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Plural-Forms: nplurals=4; plural=(n==1 ? 0 : n==2 ? 1 : (n<7 ? 2 : 3));\n"
+
+#: ui/menu.c:10
+msgid "ui.title"
+msgstr ""
+"Welcome"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.general"
+msgstr "General"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.input"
+msgstr "Input"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.display"
+msgstr "Display"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.audio"
+msgstr "Audio"
+
+msgid "ui.settings.input.deadzone"
+msgstr "Deadzone"
+
+#: src/dusk/ui/frame/settings/uisettingsgeneral.c
+msgid "ui.settings.general.language"
+msgstr "Language"
+
+msgid "ui.settings.general.language_detail"
+msgstr "Takes effect after restarting the application."
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.apply"
+msgstr "Apply"
+
+#: src/dusk/ui/frame/uiconfirm.c
+msgid "ui.confirm.discard_changes"
+msgstr "Discard unsaved changes?"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.characters"
+msgstr "Characters"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.items"
+msgstr "Items"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.settings"
+msgstr "Settings"
+
+msgid "item.potion.name"
+msgstr "Potion"
+
+msgid "item.potato.name"
+msgstr "Potato"
+
+msgid "item.apple.name"
+msgstr "Apple"

assets/locale/es_MX.po

@@ -0,0 +1,70 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: ExampleApp 1.0\n"
+"Language: es\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Plural-Forms: nplurals=2; plural=(n==1 ? 0 : 1);\n"
+
+#: ui/menu.c:10
+msgid "ui.title"
+msgstr ""
+"Bienvenido"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.general"
+msgstr "General"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.input"
+msgstr "Entrada"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.display"
+msgstr "Pantalla"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.audio"
+msgstr "Audio"
+
+msgid "ui.settings.input.deadzone"
+msgstr "Deadzone"
+
+#: src/dusk/ui/frame/settings/uisettingsgeneral.c
+msgid "ui.settings.general.language"
+msgstr "Idioma"
+
+#: src/dusk/ui/frame/settings/uisettingsgeneral.c
+msgid "ui.settings.general.language_detail"
+msgstr "Se aplica después de reiniciar la aplicación."
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.apply"
+msgstr "Aplicar"
+
+#: src/dusk/ui/frame/uiconfirm.c
+msgid "ui.confirm.discard_changes"
+msgstr "¿Descartar los cambios no guardados?"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.characters"
+msgstr "Personajes"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.items"
+msgstr "Objetos"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.settings"
+msgstr "Configuración"
+
+#: src/dusk/rpg/item/item.json
+msgid "item.potion.name"
+msgstr "Poción"
+
+#: src/dusk/rpg/item/item.json
+msgid "item.potato.name"
+msgstr "Papa"
+
+#: src/dusk/rpg/item/item.json
+msgid "item.apple.name"
+msgstr "Manzana"

assets/locale/jp_JP.po

@@ -0,0 +1,70 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: ExampleApp 1.0\n"
+"Language: ja\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Plural-Forms: nplurals=1; plural=(0);\n"
+
+#: ui/menu.c:10
+msgid "ui.title"
+msgstr ""
+"歓迎"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.general"
+msgstr "一般"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.input"
+msgstr "入力"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.display"
+msgstr "表示"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.tabs.audio"
+msgstr "オーディオ"
+
+msgid "ui.settings.input.deadzone"
+msgstr "デッドゾーン"
+
+#: src/dusk/ui/frame/settings/uisettingsgeneral.c
+msgid "ui.settings.general.language"
+msgstr "言語"
+
+#: src/dusk/ui/frame/settings/uisettingsgeneral.c
+msgid "ui.settings.general.language_detail"
+msgstr "アプリケーションを再起動すると適用されます。"
+
+#: src/dusk/ui/frame/settings/uisettings.c
+msgid "ui.settings.apply"
+msgstr "適用"
+
+#: src/dusk/ui/frame/uiconfirm.c
+msgid "ui.confirm.discard_changes"
+msgstr "未保存の変更を破棄しますか？"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.characters"
+msgstr "キャラクター"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.items"
+msgstr "アイテム"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.settings"
+msgstr "設定"
+
+#: src/dusk/rpg/item/item.json
+msgid "item.potion.name"
+msgstr "ポーション"
+
+#: src/dusk/rpg/item/item.json
+msgid "item.potato.name"
+msgstr "ジャガイモ"
+
+#: src/dusk/rpg/item/item.json
+msgid "item.apple.name"
+msgstr "リンゴ"

assets/scripts/Button.js

@@ -0,0 +1,49 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// Gamepad/keyboard-only for now -- no mouse support exists in the input
+// system yet. Something else (e.g. a future Menu widget) is responsible
+// for moving `highlighted` between multiple buttons; a Button only knows
+// how to fire onSelect() when ACCEPT is pressed while it's the highlighted
+// one.
+class Button extends UIElement {
+  init() {
+    this.background = new Rectangle();
+    this.background.width = 120;
+    this.background.height = 32;
+    this.background.color = Button.COLOR_NORMAL;
+    this.add(this.background);
+
+    this.label = new Label();
+    this.label.x = 8;
+    this.label.y = 8;
+    this.add(this.label);
+
+    this.highlighted = false;
+    this.onSelect = null;
+  }
+
+  get text() { return this.label.text; }
+  set text(value) { this.label.text = value; }
+
+  setHighlighted(highlighted) {
+    this.highlighted = highlighted;
+    this.background.color = highlighted
+      ? Button.COLOR_HIGHLIGHTED
+      : Button.COLOR_NORMAL;
+  }
+
+  update() {
+    this.updateChildren();
+    if(this.highlighted && Input.pressed(InputBind.ACCEPT) && this.onSelect) {
+      this.onSelect();
+    }
+  }
+}
+
+Button.COLOR_NORMAL = { r: 255, g: 255, b: 255, a: 255 };
+Button.COLOR_HIGHLIGHTED = { r: 255, g: 0, b: 0, a: 255 };
+
+module.exports = Button;

assets/scripts/Checkbox.js

@@ -0,0 +1,61 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// A single label showing "Y "/"N " + the caller's text -- no background,
+// matching the old widget exactly. Toggling itself (checked) is driven
+// externally, typically by a Menu handing it LEFT/RIGHT via
+// directionInput() while this checkbox is the highlighted item.
+class Checkbox extends UIElement {
+  init() {
+    this.label = new Label();
+    this.add(this.label);
+
+    this._text = '';
+    this._checked = false;
+    this.highlighted = false;
+
+    this._refresh();
+  }
+
+  get text() { return this._text; }
+  set text(value) {
+    this._text = value;
+    this._refresh();
+  }
+
+  get checked() { return this._checked; }
+  set checked(value) {
+    this._checked = value;
+    this._refresh();
+  }
+
+  toggle() {
+    this.checked = !this.checked;
+  }
+
+  setHighlighted(highlighted) {
+    this.highlighted = highlighted;
+    this.label.color = highlighted
+      ? Checkbox.COLOR_HIGHLIGHTED
+      : Checkbox.COLOR_NORMAL;
+  }
+
+  // Menu direction-input opt-out hook: LEFT/RIGHT toggles and consumes
+  // the input; UP/DOWN falls through to default cursor movement.
+  directionInput(dx, dy) {
+    if(dx === 0) return false;
+    this.toggle();
+    return true;
+  }
+
+  _refresh() {
+    this.label.text = (this._checked ? 'Y ' : 'N ') + this._text;
+  }
+}
+
+Checkbox.COLOR_NORMAL = { r: 255, g: 255, b: 255, a: 255 };
+Checkbox.COLOR_HIGHLIGHTED = { r: 255, g: 0, b: 0, a: 255 };
+
+module.exports = Checkbox;

assets/scripts/Confirm.js

@@ -0,0 +1,110 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+var Menu = require('./Menu.js');
+var Button = require('./Button.js');
+
+// A Yes/No dialog: dim full-screen backdrop + a flat-color panel (see
+// Fullbox.js/plan notes on why there's no real 9-slice Frame yet) +
+// text + a 2-item Menu. Confirm.open(text, callback) lazily creates and
+// reuses ONE shared instance rather than allocating fresh every time --
+// the Menu stack already guarantees at most one confirm is ever
+// meaningfully active, so there's nothing to gain from a fresh instance
+// per call, and it sidesteps ever needing to dispose one (see Fullbox.js
+// for why disposing from inside your own callback chain is risky).
+class Confirm extends UIElement {
+  init() {
+    this.backdrop = new Rectangle();
+    this.backdrop.color = Confirm.COLOR_BACKDROP;
+    this.add(this.backdrop);
+
+    this.panel = new Rectangle();
+    this.panel.width = Confirm.PANEL_WIDTH;
+    this.panel.height = Confirm.PANEL_HEIGHT;
+    this.panel.color = Confirm.COLOR_PANEL;
+    this.add(this.panel);
+
+    this.label = new Label();
+    this.add(this.label);
+
+    this.menu = new Menu();
+    this.menu.cols = 2;
+    this.add(this.menu);
+
+    this.confirmButton = new Button();
+    this.confirmButton.text = 'Confirm';
+    this.menu.addItem(this.confirmButton);
+
+    this.cancelButton = new Button();
+    this.cancelButton.text = 'Cancel';
+    this.menu.addItem(this.cancelButton);
+
+    this.menu.onSelected = (index) => this._finish(index === 0);
+    // CANCEL (the bind, not the button) also closes the menu without
+    // firing onSelected -- treat that the same as picking Cancel.
+    this.menu.onClosed = () => this._finish(false);
+
+    this._callback = null;
+    this._finishing = false;
+  }
+
+  open(text, callback) {
+    this.label.text = text;
+    this._callback = callback;
+    this._finishing = false;
+
+    this._layout();
+
+    UI.add(this);
+    this.menu.open();
+  }
+
+  _finish(result) {
+    // menu.onClosed calling back into _finish (via close() below) would
+    // otherwise recurse into itself.
+    if(this._finishing) return;
+    this._finishing = true;
+
+    this.menu.close();
+    UI.remove(this);
+
+    const callback = this._callback;
+    this._callback = null;
+    if(callback) callback(result);
+  }
+
+  _layout() {
+    this.backdrop.width = Screen.width;
+    this.backdrop.height = Screen.height;
+
+    const panelX = (Screen.width - Confirm.PANEL_WIDTH) / 2;
+    const panelY = (Screen.height - Confirm.PANEL_HEIGHT) / 2;
+    this.panel.x = panelX;
+    this.panel.y = panelY;
+
+    this.label.x = panelX + Confirm.PADDING;
+    this.label.y = panelY + Confirm.PADDING;
+
+    this.confirmButton.x = panelX + Confirm.PADDING;
+    this.confirmButton.y = panelY + Confirm.PANEL_HEIGHT - Confirm.PADDING - 32;
+
+    this.cancelButton.x = this.confirmButton.x + 130;
+    this.cancelButton.y = this.confirmButton.y;
+  }
+}
+
+Confirm.PANEL_WIDTH = 300;
+Confirm.PANEL_HEIGHT = 120;
+Confirm.PADDING = 16;
+Confirm.COLOR_BACKDROP = { r: 0, g: 0, b: 0, a: 160 };
+Confirm.COLOR_PANEL = { r: 40, g: 40, b: 40, a: 255 };
+
+Confirm.open = function(text, callback) {
+  if(!Confirm._shared) Confirm._shared = new Confirm();
+  Confirm._shared.open(text, callback);
+  return Confirm._shared;
+};
+
+module.exports = Confirm;

assets/scripts/ConsoleOverlay.js

@@ -0,0 +1,60 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// One Label per console history slot, refreshed only when
+// Console.consumeDirty() says the history actually changed -- reuses
+// the normal Label/spritebatch render path instead of the old
+// hand-rolled mesh-cache renderer.
+//
+// These Labels are NOT add()ed as children -- UIElement.add() caps at 8
+// children per element, and CONSOLE_HISTORY_MAX (Console.lineCount) is
+// 16, over that cap. Instead they're driven directly: render()/update()
+// called explicitly below, and their world position is just their own
+// x/y (never having a parent means nothing offsets it).
+class ConsoleOverlay extends UIElement {
+  init() {
+    this.lines = [];
+    for(let i = 0; i < Console.lineCount; i++) {
+      const label = new Label();
+      label.x = 4;
+      label.y = 4 + i * ConsoleOverlay.LINE_HEIGHT;
+      this.lines.push(label);
+    }
+
+    this._refresh();
+  }
+
+  update() {
+    this.updateChildren();
+    if(Console.consumeDirty()) this._refresh();
+    for(let i = 0; i < this.lines.length; i++) this.lines[i].update();
+  }
+
+  // Overridden (rather than left to auto-render) so the console can be
+  // hidden entirely without disposing/rebuilding its Labels.
+  render() {
+    this.renderChildren();
+    if(!Console.visible) return;
+    for(let i = 0; i < this.lines.length; i++) this.lines[i].render();
+  }
+
+  // this.lines was never add()ed, so the normal dispose() cascade can't
+  // reach them -- release them explicitly first, or they'd leak their
+  // pool slots.
+  dispose() {
+    for(let i = 0; i < this.lines.length; i++) this.lines[i].dispose();
+    super.dispose();
+  }
+
+  _refresh() {
+    for(let i = 0; i < this.lines.length; i++) {
+      this.lines[i].text = Console.getLine(i);
+    }
+  }
+}
+
+ConsoleOverlay.LINE_HEIGHT = 12;
+
+module.exports = ConsoleOverlay;

assets/scripts/Crop.js

@@ -0,0 +1,64 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// Up to 4 black letterbox/pillarbox bars sized from Screen.scanX/Y/
+// scanWidth/scanHeight vs Screen.width/height. Recomputed every tick,
+// unconditionally -- cheap (four rectangle field writes), and a no-op
+// when the scan area already covers the full viewport (Rectangle
+// already skips rendering at width/height <= 0).
+class Crop extends UIElement {
+  init() {
+    this.top = new Rectangle();
+    this.bottom = new Rectangle();
+    this.left = new Rectangle();
+    this.right = new Rectangle();
+
+    this.top.color = Crop.COLOR_BARS;
+    this.bottom.color = Crop.COLOR_BARS;
+    this.left.color = Crop.COLOR_BARS;
+    this.right.color = Crop.COLOR_BARS;
+
+    this.add(this.top);
+    this.add(this.bottom);
+    this.add(this.left);
+    this.add(this.right);
+  }
+
+  update() {
+    this.updateChildren();
+    this._refresh();
+  }
+
+  _refresh() {
+    const scanX = Screen.scanX;
+    const scanY = Screen.scanY;
+    const scanRight = scanX + Screen.scanWidth;
+    const scanBottom = scanY + Screen.scanHeight;
+
+    this.top.x = 0;
+    this.top.y = 0;
+    this.top.width = Screen.width;
+    this.top.height = scanY;
+
+    this.bottom.x = 0;
+    this.bottom.y = scanBottom;
+    this.bottom.width = Screen.width;
+    this.bottom.height = Screen.height - scanBottom;
+
+    this.left.x = 0;
+    this.left.y = scanY;
+    this.left.width = scanX;
+    this.left.height = Screen.scanHeight;
+
+    this.right.x = scanRight;
+    this.right.y = scanY;
+    this.right.width = Screen.width - scanRight;
+    this.right.height = Screen.scanHeight;
+  }
+}
+
+Crop.COLOR_BARS = { r: 0, g: 0, b: 0, a: 255 };
+
+module.exports = Crop;

assets/scripts/Dropdown.js

@@ -0,0 +1,68 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// Label + a "< option >"-style value label, cycling a caller-provided
+// options array. Same directionInput()-consumes-LEFT/RIGHT shape as
+// Slider, stepping the selected index (with wraparound) instead of a
+// numeric value.
+class Dropdown extends UIElement {
+  init() {
+    this.label = new Label();
+    this.add(this.label);
+
+    this.valueLabel = new Label();
+    this.valueLabel.x = 100;
+    this.add(this.valueLabel);
+
+    this.options = [];
+    this._index = 0;
+    this.highlighted = false;
+    this.onChange = null;
+
+    this._refresh();
+  }
+
+  get text() { return this.label.text; }
+  set text(value) { this.label.text = value; }
+
+  get selectedIndex() { return this._index; }
+  set selectedIndex(index) {
+    if(this.options.length === 0) {
+      this._index = 0;
+      this._refresh();
+      return;
+    }
+
+    const count = this.options.length;
+    this._index = ((index % count) + count) % count;
+    this._refresh();
+    if(this.onChange) this.onChange(this._index, this.options[this._index]);
+  }
+
+  get selected() { return this.options[this._index]; }
+
+  setHighlighted(highlighted) {
+    this.highlighted = highlighted;
+    this.label.color = highlighted
+      ? Dropdown.COLOR_HIGHLIGHTED
+      : Dropdown.COLOR_NORMAL;
+  }
+
+  directionInput(dx, dy) {
+    if(dx === 0) return false;
+    this.selectedIndex = this._index + dx;
+    return true;
+  }
+
+  _refresh() {
+    const value = this.options[this._index];
+    this.valueLabel.text = value !== undefined ? ('< ' + value + ' >') : '< >';
+  }
+}
+
+Dropdown.COLOR_NORMAL = { r: 255, g: 255, b: 255, a: 255 };
+Dropdown.COLOR_HIGHLIGHTED = { r: 255, g: 0, b: 0, a: 255 };
+
+module.exports = Dropdown;

assets/scripts/FpsCounter.js

@@ -0,0 +1,43 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// extends UIElement (not Label) deliberately: only a UIElement/SCRIPTED
+// instance's render()/update() override actually gets dispatched by the
+// engine (the native Label/Rectangle callback tables never consult a
+// subclass's override -- they're not scripted types themselves). So this
+// composes a child Label instead of subclassing one, same as Button.
+//
+// Overrides render() rather than update(): update()/uiUpdate() only run
+// on the one fixed-timestep tick per real frame that actually crosses a
+// DUSK_TIME_STEP boundary (see Time.renderDelta's doc), but an FPS
+// counter needs to sample every real frame -- which is exactly what
+// render() does.
+class FpsCounter extends UIElement {
+  init() {
+    this.label = new Label();
+    this.add(this.label);
+
+    this._average = 0;
+  }
+
+  render() {
+    const delta = Time.renderDelta;
+    if(delta > 0) {
+      const fps = 1 / delta;
+      this._average = this._average === 0
+        ? fps
+        : this._average + (fps - this._average) * FpsCounter.SMOOTHING;
+    }
+
+    this.label.text = 'FPS: ' + Math.round(this._average);
+    this.renderChildren();
+  }
+}
+
+// Exponential-moving-average weight per sample -- lower is smoother/
+// slower to react, higher tracks instantaneous frame time more closely.
+FpsCounter.SMOOTHING = 0.1;
+
+module.exports = FpsCounter;

assets/scripts/Fullbox.js

@@ -0,0 +1,98 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// A tweened full-screen color quad -- covers both the old uifullbox
+// (full-screen fade) and uitransition (fade transition with a
+// completion callback): same shape, just parameterized, so there's no
+// separate transition class/global.
+//
+// extends UIElement composing a child Rectangle (not extends Rectangle)
+// for the same reason as FpsCounter: only a UIElement/SCRIPTED
+// instance's render() override is actually dispatched by the engine.
+// Overrides render() (not update()) so the tween advances every real
+// frame, not just on fixed-timestep ticks.
+//
+// A finished Fullbox is only removed from the overlay roots, never
+// disposed -- disposing an element from inside its own render()
+// callback would free its JS instance registration while a native C
+// caller further up the same call stack still holds it, risking the
+// exact kind of delayed JerryScript refcount corruption this project
+// has already hit once. Fullbox.under()/over() lazily create and cache
+// one shared, reusable instance each (mirroring the old UNDER/OVER
+// singletons), so repeated fades cost zero additional pool slots.
+class Fullbox extends UIElement {
+  init() {
+    this.rect = new Rectangle();
+    this.add(this.rect);
+
+    this._from = Fullbox.COLOR_TRANSPARENT;
+    this._to = Fullbox.COLOR_TRANSPARENT;
+    this._duration = 0;
+    this._t = 0;
+    this._onComplete = null;
+    this._active = false;
+  }
+
+  // Starts (or restarts) this Fullbox tweening rect.color from
+  // options.fromColor to options.toColor over options.duration seconds,
+  // calling options.onComplete() once when done. Adds itself to the
+  // overlay roots if it isn't already there.
+  play(options) {
+    this._from = options.fromColor || Fullbox.COLOR_TRANSPARENT;
+    this._to = options.toColor || Fullbox.COLOR_TRANSPARENT;
+    this._duration = options.duration || 0;
+    this._t = 0;
+    this._onComplete = options.onComplete || null;
+    this._active = true;
+
+    this.rect.width = Screen.width;
+    this.rect.height = Screen.height;
+    this.rect.color = this._from;
+
+    UI.addOverlay(this);
+  }
+
+  render() {
+    if(this._active) {
+      this._t += Time.renderDelta;
+      const ratio = this._duration > 0
+        ? Math.min(1, this._t / this._duration)
+        : 1;
+
+      this.rect.color = Fullbox._lerpColor(this._from, this._to, ratio);
+
+      if(ratio >= 1) {
+        this._active = false;
+        UI.removeOverlay(this);
+        if(this._onComplete) this._onComplete();
+      }
+    }
+
+    this.renderChildren();
+  }
+}
+
+Fullbox.COLOR_TRANSPARENT = { r: 0, g: 0, b: 0, a: 0 };
+
+Fullbox._lerpColor = function(from, to, t) {
+  return {
+    r: from.r + (to.r - from.r) * t,
+    g: from.g + (to.g - from.g) * t,
+    b: from.b + (to.b - from.b) * t,
+    a: from.a + (to.a - from.a) * t
+  };
+};
+
+Fullbox.under = function() {
+  if(!Fullbox._under) Fullbox._under = new Fullbox();
+  return Fullbox._under;
+};
+
+Fullbox.over = function() {
+  if(!Fullbox._over) Fullbox._over = new Fullbox();
+  return Fullbox._over;
+};
+
+module.exports = Fullbox;

assets/scripts/Menu.js

@@ -0,0 +1,187 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// Gamepad/keyboard focus-navigation, replacing the old global uifocus_t
+// stack. A Menu's children still render/update through the normal tree
+// (add()), but navigation uses its own `items` list -- addItem() calls
+// add() and also tracks the widget as focusable, so decorative elements
+// (a title Label, a Rectangle background) just use add() directly and
+// never enter navigation.
+//
+// open()/close() push/pop this Menu on a small global stack -- only the
+// topmost entry consumes CANCEL/ACCEPT/direction input each tick, so a
+// Menu opened on top of another (e.g. a Settings sub-page menu, or a
+// Confirm dialog) doesn't fight it for input; everything underneath
+// keeps rendering/updating, just doesn't react to input until it's
+// topmost again.
+class Menu extends UIElement {
+  init() {
+    this.items = [];
+    this.cols = 1;
+    this.index = 0;
+
+    this.onSelected = null;
+    this.onChanged = null;
+    this.onClosed = null;
+
+    this._heldDir = null;
+    this._heldTime = 0;
+  }
+
+  addItem(widget) {
+    this.add(widget);
+    this.items.push(widget);
+    return widget;
+  }
+
+  open() {
+    if(Menu._stack.indexOf(this) !== -1) return;
+    Menu._stack.push(this);
+
+    const item = this.items[this.index];
+    if(item && item.setHighlighted) item.setHighlighted(true);
+  }
+
+  // Closes this Menu and anything opened on top of it, matching the old
+  // uifocus_t's uiFocusPopItem (popping a mid-stack item also pops
+  // everything above it).
+  close() {
+    const idx = Menu._stack.indexOf(this);
+    if(idx === -1) return;
+
+    while(Menu._stack.length > idx) {
+      Menu._stack.pop()._onClosed();
+    }
+  }
+
+  // Safety net: dispose() has no override-preserving trampoline the way
+  // render()/update() do (see UIElement's dispose() docs), so a bare
+  // this.menu.dispose() would leave a disposed instance stuck at the top
+  // of Menu._stack forever if the caller forgot to close() first --
+  // always close() (a no-op if never opened) before the native cascade.
+  dispose() {
+    this.close();
+    super.dispose();
+  }
+
+  _onClosed() {
+    for(let i = 0; i < this.items.length; i++) {
+      const item = this.items[i];
+      if(item.setHighlighted) item.setHighlighted(false);
+    }
+    if(this.onClosed) this.onClosed();
+  }
+
+  update() {
+    this.updateChildren();
+
+    if(Menu.top() !== this) return;
+
+    if(Input.pressed(InputBind.CANCEL)) {
+      this.close();
+      return;
+    }
+
+    if(Input.pressed(InputBind.ACCEPT) && this.onSelected) {
+      this.onSelected(this.index, this.items[this.index]);
+    }
+
+    this._handleDirection();
+  }
+
+  _handleDirection() {
+    const dir = this._currentDirection();
+
+    if(!dir) {
+      this._heldDir = null;
+      this._heldTime = 0;
+      return;
+    }
+
+    if(dir !== this._heldDir) {
+      this._heldDir = dir;
+      this._heldTime = 0;
+      this._moveDirection(dir.dx, dir.dy);
+      return;
+    }
+
+    this._heldTime += Time.delta;
+    if(this._heldTime >= Menu.HOLD_DELAY) {
+      this._heldTime -= Menu.HOLD_REPEAT;
+      this._moveDirection(dir.dx, dir.dy);
+    }
+  }
+
+  // Identity-stable direction markers so _handleDirection's `dir !==
+  // this._heldDir` check works without allocating a fresh object (and
+  // therefore never matching) every tick.
+  _currentDirection() {
+    if(Input.isDown(InputBind.LEFT)) return Menu.DIR_LEFT;
+    if(Input.isDown(InputBind.RIGHT)) return Menu.DIR_RIGHT;
+    if(Input.isDown(InputBind.UP)) return Menu.DIR_UP;
+    if(Input.isDown(InputBind.DOWN)) return Menu.DIR_DOWN;
+    return null;
+  }
+
+  // Gives the currently-highlighted item first refusal (a Slider/
+  // Dropdown/Checkbox consuming LEFT/RIGHT itself), falling back to
+  // moving the cursor -- mirrors uifocus_t's per-item `direction`
+  // callback.
+  _moveDirection(dx, dy) {
+    if(this.items.length === 0) return;
+
+    const item = this.items[this.index];
+    if(item && typeof item.directionInput === 'function') {
+      if(item.directionInput(dx, dy)) return;
+    }
+
+    this._moveIndex(dx, dy);
+  }
+
+  _moveIndex(dx, dy) {
+    const count = this.items.length;
+    if(count === 0) return;
+
+    const cols = Math.max(1, this.cols);
+    const rows = Math.ceil(count / cols);
+
+    const col = ((this.index % cols) + dx + cols) % cols;
+    const row = ((Math.floor(this.index / cols)) + dy + rows) % rows;
+
+    let next = row * cols + col;
+    if(next >= count) next = count - 1;
+
+    this._setIndex(next);
+  }
+
+  _setIndex(next) {
+    if(next === this.index) return;
+
+    const oldItem = this.items[this.index];
+    if(oldItem && oldItem.setHighlighted) oldItem.setHighlighted(false);
+
+    this.index = next;
+
+    const newItem = this.items[this.index];
+    if(newItem && newItem.setHighlighted) newItem.setHighlighted(true);
+
+    if(this.onChanged) this.onChanged(this.index, newItem);
+  }
+}
+
+Menu._stack = [];
+Menu.top = function() {
+  return Menu._stack.length > 0 ? Menu._stack[Menu._stack.length - 1] : null;
+};
+
+Menu.HOLD_DELAY = 0.5;
+Menu.HOLD_REPEAT = 0.1;
+
+Menu.DIR_LEFT = { dx: -1, dy: 0 };
+Menu.DIR_RIGHT = { dx: 1, dy: 0 };
+Menu.DIR_UP = { dx: 0, dy: -1 };
+Menu.DIR_DOWN = { dx: 0, dy: 1 };
+
+module.exports = Menu;

assets/scripts/OverworldScene.js

@@ -0,0 +1,52 @@
+var Player = require('./Player.js');
+var PlayerCamera = require('./PlayerCamera.js');
+var TestPlane = require('./TestPlane.js');
+var TestUIElement = require('./TestUIElement.js');
+var FpsCounter = require('./FpsCounter.js');
+var ConsoleOverlay = require('./ConsoleOverlay.js');
+
+class OverworldScene {
+  constructor() {
+  }
+
+  init() {
+    this.player = new Player();
+    this.plane = new TestPlane();
+    this.camera = new PlayerCamera(this.player);
+
+    this.testUi = new TestUIElement();
+    UI.add(this.testUi);
+
+    this.fpsCounter = new FpsCounter();
+    UI.addOverlay(this.fpsCounter);
+
+    this.consoleOverlay = new ConsoleOverlay();
+    UI.addOverlay(this.consoleOverlay);
+  }
+
+  lateUpdate() {
+    this.camera.update();
+  }
+
+  dispose() {
+    this.camera.dispose();
+    this.player.dispose();
+    this.plane.dispose();
+
+    // testUi.dispose() cascades to its background/label children and
+    // removes itself from UI's render roots -- no separate UI.remove()
+    // needed.
+    this.testUi.dispose();
+    this.fpsCounter.dispose();
+    this.consoleOverlay.dispose();
+
+    this.camera = null; 
+    this.player = null;
+    this.plane = null;
+    this.testUi = null;
+    this.fpsCounter = null;
+    this.consoleOverlay = null;
+  }
+}
+
+module.exports = OverworldScene;

assets/scripts/Player.js

@@ -0,0 +1,28 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+class Player extends Entity {
+  constructor() {
+    super();
+
+    this.position = this.add(POSITION);
+    this.position.setLocalPosition(0.0, 2.0, 0.0);
+
+    this.physics = this.add(PHYSICS);
+    this.physics.setShape(PHYSICS_SHAPE_CAPSULE, 0.5, 0.5);
+
+    this.renderable = this.add(RENDERABLE);
+    this.renderable.setMesh(0, MESH_CAPSULE);
+    this.renderable.setColor(0, 0, 255, 255);
+
+    this.add(PLAYER);
+  }
+
+  dispose() {
+    
+  }
+}
+
+module.exports = Player;

assets/scripts/PlayerCamera.js

@@ -0,0 +1,41 @@
+var CAMERA_OFFSET_ANGLE = 0.0;
+var CAMERA_OFFSET_RADIUS = 18.0;
+var CAMERA_OFFSET_HEIGHT = 10.0;
+
+class PlayerCamera extends Entity {
+  constructor(target) {
+    super();
+    this.target = target;
+
+    this.position = this.add(POSITION);
+    this.add(CAMERA);
+
+    this.update();
+  }
+
+  update() {
+    var targetPosition = this.target.position.getLocalPosition();
+
+    var eyeX = (
+      targetPosition.x + Math.cos(CAMERA_OFFSET_ANGLE) * CAMERA_OFFSET_RADIUS
+    );
+    var eyeY = (
+      targetPosition.y + CAMERA_OFFSET_HEIGHT
+    );
+    var eyeZ = (
+      targetPosition.z + Math.sin(CAMERA_OFFSET_ANGLE) * CAMERA_OFFSET_RADIUS
+    );
+
+    this.position.lookAt(
+      eyeX, eyeY, eyeZ,
+      targetPosition.x, targetPosition.y, targetPosition.z,
+      0.0, 1.0, 0.0
+    );
+  }
+
+  dispose() {
+    this.target = null;
+  }
+}
+
+module.exports = PlayerCamera;

assets/scripts/Settings.js

@@ -0,0 +1,96 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+var Menu = require('./Menu.js');
+var Tab = require('./Tab.js');
+var Confirm = require('./Confirm.js');
+var SettingsGeneral = require('./SettingsGeneral.js');
+var SettingsInput = require('./SettingsInput.js');
+
+// Display/Audio pages are deliberately not here -- neither has any real
+// engine system behind it, even in the old code (no resolution/
+// fullscreen system, no audio subsystem at all).
+var TABS = [
+  { name: 'General', ctor: SettingsGeneral },
+  { name: 'Input', ctor: SettingsInput }
+];
+
+// Owns a tabs Menu (General/Input) and swaps in the active tab's page
+// widgets into a second, page-scoped Menu -- both Menus are open on the
+// navigation stack simultaneously (tabsMenu below, pageMenu on top),
+// matching the old settings screen's nested-menu behavior. Switching
+// away from a dirty page opens a Confirm first.
+class Settings extends UIElement {
+  init() {
+    this.tabsMenu = new Menu();
+    this.tabsMenu.cols = TABS.length;
+    this.add(this.tabsMenu);
+
+    this.tabs = TABS.map((def, index) => {
+      const tab = new Tab();
+      tab.text = def.name;
+      tab.x = index * 90;
+      this.tabsMenu.addItem(tab);
+      return tab;
+    });
+
+    this.tabsMenu.onSelected = (index) => this._activateTab(index);
+
+    this.page = null;
+    this.pageMenu = null;
+    this._activeTabIndex = -1;
+  }
+
+  open() {
+    UI.add(this);
+    this.tabsMenu.open();
+    this._activateTab(0);
+  }
+
+  close() {
+    this.tabsMenu.close();
+    if(this.pageMenu) this.pageMenu.close();
+    UI.remove(this);
+  }
+
+  _activateTab(index) {
+    if(index === this._activeTabIndex) return;
+
+    if(this.page && this.page.hasChanges && this.page.hasChanges()) {
+      Confirm.open('Discard changes?', (confirmed) => {
+        if(confirmed) this._swapTab(index);
+      });
+      return;
+    }
+
+    this._swapTab(index);
+  }
+
+  _swapTab(index) {
+    // pageMenu.dispose() cascades to every widget the outgoing page
+    // handed it via menuItems -- the page itself is a plain object (see
+    // SettingsGeneral.js), nothing else to release.
+    if(this.pageMenu) this.pageMenu.dispose();
+
+    for(let i = 0; i < this.tabs.length; i++) {
+      this.tabs[i].setHighlighted(i === index);
+    }
+
+    const def = TABS[index];
+    this.page = new def.ctor();
+    if(this.page.load) this.page.load();
+
+    this.pageMenu = new Menu();
+    this.pageMenu.y = 40;
+    const items = this.page.menuItems || [];
+    for(let i = 0; i < items.length; i++) this.pageMenu.addItem(items[i]);
+    this.add(this.pageMenu);
+    this.pageMenu.open();
+
+    this._activeTabIndex = index;
+  }
+}
+
+module.exports = Settings;

assets/scripts/SettingsGeneral.js

@@ -0,0 +1,48 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+var Dropdown = require('./Dropdown.js');
+var Button = require('./Button.js');
+
+// A plain class, not a UIElement -- it owns no visual tree of its own.
+// Its widgets are handed to Settings.js's pageMenu (via menuItems),
+// which owns their parenting/rendering/disposal; this only holds
+// load()/apply()/hasChanges() logic, mirroring the old settings system's
+// per-tab def struct.
+class SettingsGeneral {
+  constructor() {
+    this.dropdown = new Dropdown();
+    this.dropdown.text = 'Language';
+    this.dropdown.options = ['en-US', 'ja-JP', 'es-MX'];
+
+    this.applyButton = new Button();
+    this.applyButton.text = 'Apply';
+    this.applyButton.y = 40;
+    this.applyButton.onSelect = () => this.apply();
+
+    this._loadedIndex = 0;
+  }
+
+  get menuItems() {
+    return [this.dropdown, this.applyButton];
+  }
+
+  load() {
+    const index = this.dropdown.options.indexOf(Locale.current);
+    this.dropdown.selectedIndex = index >= 0 ? index : 0;
+    this._loadedIndex = this.dropdown.selectedIndex;
+  }
+
+  apply() {
+    Locale.set(this.dropdown.options[this.dropdown.selectedIndex]);
+    this._loadedIndex = this.dropdown.selectedIndex;
+  }
+
+  hasChanges() {
+    return this.dropdown.selectedIndex !== this._loadedIndex;
+  }
+}
+
+module.exports = SettingsGeneral;

assets/scripts/SettingsInput.js

@@ -0,0 +1,46 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+var Slider = require('./Slider.js');
+var Button = require('./Button.js');
+
+// A plain class, not a UIElement -- see SettingsGeneral.js for why.
+class SettingsInput {
+  constructor() {
+    this.deadzoneSlider = new Slider();
+    this.deadzoneSlider.text = 'Deadzone';
+    this.deadzoneSlider.min = 0;
+    this.deadzoneSlider.max = 1;
+    this.deadzoneSlider.step = 0.05;
+
+    this.applyButton = new Button();
+    this.applyButton.text = 'Apply';
+    this.applyButton.y = 40;
+    this.applyButton.onSelect = () => this.apply();
+
+    this._loadedValue = 0;
+  }
+
+  get menuItems() {
+    return [this.deadzoneSlider, this.applyButton];
+  }
+
+  load() {
+    this.deadzoneSlider.value = Input.deadzone;
+    this._loadedValue = this.deadzoneSlider.value;
+  }
+
+  apply() {
+    Input.deadzone = this.deadzoneSlider.value;
+    Save.write();
+    this._loadedValue = this.deadzoneSlider.value;
+  }
+
+  hasChanges() {
+    return this.deadzoneSlider.value !== this._loadedValue;
+  }
+}
+
+module.exports = SettingsInput;

assets/scripts/Slider.js

@@ -0,0 +1,94 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// Name label + value label + a track/fill Rectangle pair. Unlike Button,
+// a Slider doesn't fire on ACCEPT -- it consumes LEFT/RIGHT itself via
+// directionInput(), stepping value with wraparound at min/max, which is
+// how a Menu gives the currently-highlighted item first refusal on
+// direction input before falling back to moving the cursor.
+class Slider extends UIElement {
+  init() {
+    this.nameLabel = new Label();
+    this.add(this.nameLabel);
+
+    this.valueLabel = new Label();
+    this.valueLabel.x = 100;
+    this.add(this.valueLabel);
+
+    this.track = new Rectangle();
+    this.track.y = 16;
+    this.track.width = 100;
+    this.track.height = 4;
+    this.track.color = Slider.COLOR_TRACK;
+    this.add(this.track);
+
+    this.fill = new Rectangle();
+    this.fill.y = 16;
+    this.fill.height = 4;
+    this.fill.color = Slider.COLOR_FILL;
+    this.add(this.fill);
+
+    this._min = 0;
+    this._max = 1;
+    this.step = 0.1;
+    this._value = 0;
+    this.highlighted = false;
+    this.onChange = null;
+
+    this._refresh();
+  }
+
+  get text() { return this.nameLabel.text; }
+  set text(value) { this.nameLabel.text = value; }
+
+  get min() { return this._min; }
+  set min(value) { this._min = value; this._refresh(); }
+
+  get max() { return this._max; }
+  set max(value) { this._max = value; this._refresh(); }
+
+  get value() { return this._value; }
+  set value(v) {
+    this._value = Math.min(this._max, Math.max(this._min, v));
+    this._refresh();
+    if(this.onChange) this.onChange(this._value);
+  }
+
+  setHighlighted(highlighted) {
+    this.highlighted = highlighted;
+    this.nameLabel.color = highlighted
+      ? Slider.COLOR_HIGHLIGHTED
+      : Slider.COLOR_NORMAL;
+  }
+
+  directionInput(dx, dy) {
+    if(dx === 0) return false;
+
+    let next = this._value + dx * this.step;
+    const range = this._max - this._min;
+    if(range > 0) {
+      // Wrap within [min, max) rather than clamp, matching the old
+      // slider's step-with-wraparound behavior.
+      next = this._min + (((next - this._min) % range) + range) % range;
+    }
+    this.value = next;
+    return true;
+  }
+
+  _refresh() {
+    this.valueLabel.text = String(Math.round(this._value * 100) / 100);
+    const ratio = this._max > this._min
+      ? (this._value - this._min) / (this._max - this._min)
+      : 0;
+    this.fill.width = this.track.width * ratio;
+  }
+}
+
+Slider.COLOR_NORMAL = { r: 255, g: 255, b: 255, a: 255 };
+Slider.COLOR_HIGHLIGHTED = { r: 255, g: 0, b: 0, a: 255 };
+Slider.COLOR_TRACK = { r: 80, g: 80, b: 80, a: 255 };
+Slider.COLOR_FILL = { r: 0, g: 160, b: 220, a: 255 };
+
+module.exports = Slider;

assets/scripts/Tab.js

@@ -0,0 +1,45 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+// A background Rectangle + Label, structurally a re-skinned Button --
+// "active" (which content tab is currently shown) plays the same role
+// Button's "highlighted" plays, so setHighlighted() is how a Menu drives
+// it: a tab strip's Menu treats "cursor is here" and "this tab's content
+// is showing" as the same thing, matching the old widget's behavior.
+class Tab extends UIElement {
+  init() {
+    this.background = new Rectangle();
+    this.background.width = 80;
+    this.background.height = 24;
+    this.add(this.background);
+
+    this.label = new Label();
+    this.label.x = 4;
+    this.label.y = 4;
+    this.add(this.label);
+
+    this.active = false;
+    this._refresh();
+  }
+
+  get text() { return this.label.text; }
+  set text(value) { this.label.text = value; }
+
+  setHighlighted(active) {
+    this.active = active;
+    this._refresh();
+  }
+
+  _refresh() {
+    this.background.color = this.active
+      ? Tab.COLOR_ACTIVE
+      : Tab.COLOR_INACTIVE;
+  }
+}
+
+Tab.COLOR_ACTIVE = { r: 0, g: 160, b: 0, a: 255 };
+Tab.COLOR_INACTIVE = { r: 160, g: 0, b: 0, a: 255 };
+
+module.exports = Tab;