From da3db50ca87bfa92946ed414c65133404d78b2ba Mon Sep 17 00:00:00 2001
From: Dominic Masters <dominic@domsplace.com>
Date: Mon, 8 Jun 2026 11:32:59 -0500
Subject: [PATCH] Want to test this in PSP

---
 assets/init.js                                |   7 +
 assets/testscene.js                           |   6 +-
 src/dusk/script/CMakeLists.txt                |   1 +
 .../script/module/asset/moduleassetbatch.c    | 104 ++++--------
 .../script/module/asset/moduleassetbatch.h    |  19 +++
 .../script/module/asset/moduleassetentry.c    | 110 ++++---------
 .../script/module/asset/moduleassetentry.h    |  19 +++
 src/dusk/script/module/event/moduleevent.c    |  79 ++++-----
 src/dusk/script/module/event/moduleevent.h    |  10 ++
 src/dusk/script/module/modulelist.c           |   3 +
 .../script/module/require/modulerequire.c     | 150 +++++++-----------
 .../script/module/require/modulerequire.h     |  13 --
 src/dusk/script/module/ui/CMakeLists.txt      |   1 +
 src/dusk/script/module/ui/modulefullbox.c     | 150 ++++++++++++++++++
 src/dusk/script/module/ui/modulefullbox.h     |  54 +++++++
 src/dusk/script/scriptpromisepend.c           |  83 ++++++++++
 src/dusk/script/scriptpromisepend.h           |  98 ++++++++++++
 src/dusk/ui/ui.c                              |   2 +
 src/dusk/ui/uielement.c                       |   5 +-
 types/index.d.ts                              |   1 +
 types/ui/fullbox.d.ts                         |  39 +++++
 21 files changed, 645 insertions(+), 309 deletions(-)
 create mode 100644 src/dusk/script/module/ui/modulefullbox.c
 create mode 100644 src/dusk/script/module/ui/modulefullbox.h
 create mode 100644 src/dusk/script/scriptpromisepend.c
 create mode 100644 src/dusk/script/scriptpromisepend.h
 create mode 100644 types/ui/fullbox.d.ts

diff --git a/assets/init.js b/assets/init.js
index 16b0aadd..210ad6ff 100644
--- a/assets/init.js
+++ b/assets/init.js
@@ -1,3 +1,8 @@
+// Copyright (c) 2026 Dominic Masters
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
 const platformNames = {
   [System.PLATFORM_LINUX]:    'Linux',
   [System.PLATFORM_KNULLI]:   'Knulli',
@@ -8,6 +13,8 @@ const platformNames = {
 
 Console.print('Platform: ' + (platformNames[System.platform] || 'Unknown'));
 
+UIFullboxOver.setColor(Color.BLACK);
+
 requireAsync('testscene.js').then(Scene.set).catch(err => {
   Console.print('Error loading scene: ' + err);
   Engine.exit();
diff --git a/assets/testscene.js b/assets/testscene.js
index 9999e85e..92f7aeca 100644
--- a/assets/testscene.js
+++ b/assets/testscene.js
@@ -18,7 +18,7 @@ scene.init = async function() {
   var cam = scene.cam.add(Component.CAMERA);
   camPos.localPosition = new Vec3(3, 3, 3);
   camPos.lookAt(new Vec3(0, 0, 0));
-
+  
   // Floor - large flat slab, no texture needed.
   scene.floor = Entity.create();
   var floorPos = scene.floor.add(Component.POSITION);
@@ -27,6 +27,8 @@ scene.init = async function() {
   floorR.color = Color.BLUE;
   // floorPos.localScale    = new Vec3(16, 0.2, 16);
   // floorPos.localPosition = new Vec3(0, -0.1, 0);
+
+  await UIFullboxOver.transition(Color.BLACK, Color.TRANSPARENT, 1.0);
 };
 
 scene.update = function() {
@@ -37,4 +39,4 @@ scene.dispose = function() {
   Entity.dispose(scene.cam);
 };
 
-module.exports = scene;
+module.exports = scene;
\ No newline at end of file
diff --git a/src/dusk/script/CMakeLists.txt b/src/dusk/script/CMakeLists.txt
index f9452d50..9f110960 100644
--- a/src/dusk/script/CMakeLists.txt
+++ b/src/dusk/script/CMakeLists.txt
@@ -7,6 +7,7 @@
 target_sources(${DUSK_LIBRARY_TARGET_NAME}
   PUBLIC
     script.c
+    scriptpromisepend.c
     scriptproto.c
 )
 
diff --git a/src/dusk/script/module/asset/moduleassetbatch.c b/src/dusk/script/module/asset/moduleassetbatch.c
index 314ec864..ea145c69 100644
--- a/src/dusk/script/module/asset/moduleassetbatch.c
+++ b/src/dusk/script/module/asset/moduleassetbatch.c
@@ -8,61 +8,35 @@
 #include "moduleassetbatch.h"
 #include "util/string.h"
 
-#define ASSET_BATCH_LOADED_MAX 8
-
-typedef struct {
-  assetbatch_t *batch;
-  jerry_value_t promise;
-} assetbatchloadedpend_t;
+#define ASSET_BATCH_PEND_MAX 8
 
 scriptproto_t MODULE_ASSET_BATCH_PROTO;
 
-static assetbatchloadedpend_t ASSET_BATCH_LOADED[ASSET_BATCH_LOADED_MAX];
-static uint32_t ASSET_BATCH_LOADED_COUNT = 0;
+static scriptpromisepend_t ASSET_BATCH_PEND[ASSET_BATCH_PEND_MAX];
+static uint32_t ASSET_BATCH_PEND_COUNT = 0;
 
-static void assetBatchOnLoadedFire(void *params, void *user);
-static void assetBatchOnErrorFire(void *params, void *user);
-
-static void assetBatchOnLoadedFire(void *params, void *user) {
+void assetBatchOnLoadedFire(void *params, void *user) {
   assetbatch_t *batch = (assetbatch_t *)user;
-  uint32_t i = 0;
-  while(i < ASSET_BATCH_LOADED_COUNT) {
-    if(ASSET_BATCH_LOADED[i].batch != batch) { i++; continue; }
-    jerry_value_t undef = jerry_undefined();
-    jerry_value_t r = jerry_promise_resolve(
-      ASSET_BATCH_LOADED[i].promise, undef
-    );
-    jerry_value_free(undef);
-    jerry_value_free(r);
-    jerry_value_free(ASSET_BATCH_LOADED[i].promise);
-    ASSET_BATCH_LOADED_COUNT--;
-    if(i < ASSET_BATCH_LOADED_COUNT) {
-      ASSET_BATCH_LOADED[i] =
-        ASSET_BATCH_LOADED[ASSET_BATCH_LOADED_COUNT];
-    }
-  }
+  jerry_value_t undef = jerry_undefined();
+  uint32_t n = scriptPromisePendResolve(
+    ASSET_BATCH_PEND, &ASSET_BATCH_PEND_COUNT, batch, undef
+  );
+  jerry_value_free(undef);
+  if(!n) return;
+  eventUnsubscribe(&batch->onLoaded, assetBatchOnLoadedFire);
   eventUnsubscribe(&batch->onError, assetBatchOnErrorFire);
 }
 
-static void assetBatchOnErrorFire(void *params, void *user) {
+void assetBatchOnErrorFire(void *params, void *user) {
   assetbatch_t *batch = (assetbatch_t *)user;
-  uint32_t i = 0;
-  while(i < ASSET_BATCH_LOADED_COUNT) {
-    if(ASSET_BATCH_LOADED[i].batch != batch) { i++; continue; }
-    jerry_value_t err = jerry_string_sz("Asset batch failed to load");
-    jerry_value_t r = jerry_promise_reject(
-      ASSET_BATCH_LOADED[i].promise, err
-    );
-    jerry_value_free(err);
-    jerry_value_free(r);
-    jerry_value_free(ASSET_BATCH_LOADED[i].promise);
-    ASSET_BATCH_LOADED_COUNT--;
-    if(i < ASSET_BATCH_LOADED_COUNT) {
-      ASSET_BATCH_LOADED[i] =
-        ASSET_BATCH_LOADED[ASSET_BATCH_LOADED_COUNT];
-    }
-  }
+  jerry_value_t err = jerry_string_sz("Asset batch failed to load");
+  uint32_t n = scriptPromisePendReject(
+    ASSET_BATCH_PEND, &ASSET_BATCH_PEND_COUNT, batch, err
+  );
+  jerry_value_free(err);
+  if(!n) return;
   eventUnsubscribe(&batch->onLoaded, assetBatchOnLoadedFire);
+  eventUnsubscribe(&batch->onError, assetBatchOnErrorFire);
 }
 
 void moduleAssetBatchFree(void *ptr, jerry_object_native_info_t *info) {
@@ -217,18 +191,14 @@ moduleBaseFunction(moduleAssetBatchLoaded) {
     return promise;
   }
 
-  if(ASSET_BATCH_LOADED_COUNT >= ASSET_BATCH_LOADED_MAX) {
+  if(ASSET_BATCH_PEND_COUNT >= ASSET_BATCH_PEND_MAX) {
     jerry_value_free(promise);
     return moduleBaseThrow("AssetBatch.loaded: too many pending");
   }
 
-  bool_t subscribed = false;
-  for(uint32_t i = 0; i < ASSET_BATCH_LOADED_COUNT; i++) {
-    if(ASSET_BATCH_LOADED[i].batch == b->batch) {
-      subscribed = true; break;
-    }
-  }
-  if(!subscribed) {
+  if(!scriptPromisePendHas(
+      ASSET_BATCH_PEND, ASSET_BATCH_PEND_COUNT, b->batch
+  )) {
     eventSubscribe(
       &b->batch->onLoaded, assetBatchOnLoadedFire, b->batch
     );
@@ -237,10 +207,10 @@ moduleBaseFunction(moduleAssetBatchLoaded) {
     );
   }
 
-  ASSET_BATCH_LOADED[ASSET_BATCH_LOADED_COUNT].batch = b->batch;
-  ASSET_BATCH_LOADED[ASSET_BATCH_LOADED_COUNT].promise =
-    jerry_value_copy(promise);
-  ASSET_BATCH_LOADED_COUNT++;
+  scriptPromisePendAdd(
+    ASSET_BATCH_PEND, &ASSET_BATCH_PEND_COUNT,
+    ASSET_BATCH_PEND_MAX, b->batch, promise
+  );
   return promise;
 }
 
@@ -339,7 +309,7 @@ moduleBaseFunction(moduleAssetBatchToString) {
 }
 
 void moduleAssetBatchInit(void) {
-  ASSET_BATCH_LOADED_COUNT = 0;
+  ASSET_BATCH_PEND_COUNT = 0;
   scriptProtoInit(
     &MODULE_ASSET_BATCH_PROTO, "AssetBatch",
     sizeof(jsassetbatch_t), moduleAssetBatchCtor
@@ -400,25 +370,19 @@ void moduleAssetBatchInit(void) {
 }
 
 void moduleAssetBatchDispose(void) {
-  for(uint32_t i = 0; i < ASSET_BATCH_LOADED_COUNT; i++) {
+  for(uint32_t i = 0; i < ASSET_BATCH_PEND_COUNT; i++) {
     bool_t seen = false;
     for(uint32_t j = 0; j < i; j++) {
-      if(ASSET_BATCH_LOADED[j].batch == ASSET_BATCH_LOADED[i].batch) {
+      if(ASSET_BATCH_PEND[j].key == ASSET_BATCH_PEND[i].key) {
         seen = true; break;
       }
     }
     if(!seen) {
-      eventUnsubscribe(
-        &ASSET_BATCH_LOADED[i].batch->onLoaded,
-        assetBatchOnLoadedFire
-      );
-      eventUnsubscribe(
-        &ASSET_BATCH_LOADED[i].batch->onError,
-        assetBatchOnErrorFire
-      );
+      assetbatch_t *b = (assetbatch_t *)ASSET_BATCH_PEND[i].key;
+      eventUnsubscribe(&b->onLoaded, assetBatchOnLoadedFire);
+      eventUnsubscribe(&b->onError, assetBatchOnErrorFire);
     }
-    jerry_value_free(ASSET_BATCH_LOADED[i].promise);
   }
-  ASSET_BATCH_LOADED_COUNT = 0;
+  scriptPromisePendFreeAll(ASSET_BATCH_PEND, &ASSET_BATCH_PEND_COUNT);
   scriptProtoDispose(&MODULE_ASSET_BATCH_PROTO);
 }
diff --git a/src/dusk/script/module/asset/moduleassetbatch.h b/src/dusk/script/module/asset/moduleassetbatch.h
index c7d57ac2..4067594c 100644
--- a/src/dusk/script/module/asset/moduleassetbatch.h
+++ b/src/dusk/script/module/asset/moduleassetbatch.h
@@ -8,6 +8,7 @@
 #pragma once
 #include "script/module/modulebase.h"
 #include "script/scriptproto.h"
+#include "script/scriptpromisepend.h"
 #include "script/module/asset/moduleassetentry.h"
 #include "asset/assetbatch.h"
 #include "asset/asset.h"
@@ -21,6 +22,24 @@ typedef struct {
   assetbatch_t *batch;
 } jsassetbatch_t;
 
+/**
+ * Resolves all pending loaded() promises for this batch, then
+ * unsubscribes from both onLoaded and onError.
+ *
+ * @param params Unused.
+ * @param user   The assetbatch_t pointer that finished loading.
+ */
+void assetBatchOnLoadedFire(void *params, void *user);
+
+/**
+ * Rejects all pending loaded() promises for this batch, then
+ * unsubscribes from both onLoaded and onError.
+ *
+ * @param params Unused.
+ * @param user   The assetbatch_t pointer that errored.
+ */
+void assetBatchOnErrorFire(void *params, void *user);
+
 /**
  * GC free callback - disposes and frees the batch when the JS object is
  * garbage collected.
diff --git a/src/dusk/script/module/asset/moduleassetentry.c b/src/dusk/script/module/asset/moduleassetentry.c
index 09b09564..0b228378 100644
--- a/src/dusk/script/module/asset/moduleassetentry.c
+++ b/src/dusk/script/module/asset/moduleassetentry.c
@@ -7,61 +7,35 @@
 
 #include "moduleassetentry.h"
 
-#define ASSET_ENTRY_LOADED_MAX 16
-
-typedef struct {
-  assetentry_t *entry;
-  jerry_value_t promise;
-} assetentryloadedpend_t;
+#define ASSET_ENTRY_PEND_MAX 16
 
 scriptproto_t MODULE_ASSET_ENTRY_PROTO;
 
-static assetentryloadedpend_t ASSET_ENTRY_LOADED[ASSET_ENTRY_LOADED_MAX];
-static uint32_t ASSET_ENTRY_LOADED_COUNT = 0;
+static scriptpromisepend_t ASSET_ENTRY_PEND[ASSET_ENTRY_PEND_MAX];
+static uint32_t ASSET_ENTRY_PEND_COUNT = 0;
 
-static void assetEntryOnLoadedFire(void *params, void *user);
-static void assetEntryOnErrorFire(void *params, void *user);
-
-static void assetEntryOnLoadedFire(void *params, void *user) {
+void assetEntryOnLoadedFire(void *params, void *user) {
   assetentry_t *entry = (assetentry_t *)user;
-  uint32_t i = 0;
-  while(i < ASSET_ENTRY_LOADED_COUNT) {
-    if(ASSET_ENTRY_LOADED[i].entry != entry) { i++; continue; }
-    jerry_value_t undef = jerry_undefined();
-    jerry_value_t r = jerry_promise_resolve(
-      ASSET_ENTRY_LOADED[i].promise, undef
-    );
-    jerry_value_free(undef);
-    jerry_value_free(r);
-    jerry_value_free(ASSET_ENTRY_LOADED[i].promise);
-    ASSET_ENTRY_LOADED_COUNT--;
-    if(i < ASSET_ENTRY_LOADED_COUNT) {
-      ASSET_ENTRY_LOADED[i] =
-        ASSET_ENTRY_LOADED[ASSET_ENTRY_LOADED_COUNT];
-    }
-  }
+  jerry_value_t undef = jerry_undefined();
+  uint32_t n = scriptPromisePendResolve(
+    ASSET_ENTRY_PEND, &ASSET_ENTRY_PEND_COUNT, entry, undef
+  );
+  jerry_value_free(undef);
+  if(!n) return;
+  eventUnsubscribe(&entry->onLoaded, assetEntryOnLoadedFire);
   eventUnsubscribe(&entry->onError, assetEntryOnErrorFire);
 }
 
-static void assetEntryOnErrorFire(void *params, void *user) {
+void assetEntryOnErrorFire(void *params, void *user) {
   assetentry_t *entry = (assetentry_t *)user;
-  uint32_t i = 0;
-  while(i < ASSET_ENTRY_LOADED_COUNT) {
-    if(ASSET_ENTRY_LOADED[i].entry != entry) { i++; continue; }
-    jerry_value_t err = jerry_string_sz("Asset failed to load");
-    jerry_value_t r = jerry_promise_reject(
-      ASSET_ENTRY_LOADED[i].promise, err
-    );
-    jerry_value_free(err);
-    jerry_value_free(r);
-    jerry_value_free(ASSET_ENTRY_LOADED[i].promise);
-    ASSET_ENTRY_LOADED_COUNT--;
-    if(i < ASSET_ENTRY_LOADED_COUNT) {
-      ASSET_ENTRY_LOADED[i] =
-        ASSET_ENTRY_LOADED[ASSET_ENTRY_LOADED_COUNT];
-    }
-  }
+  jerry_value_t err = jerry_string_sz("Asset failed to load");
+  uint32_t n = scriptPromisePendReject(
+    ASSET_ENTRY_PEND, &ASSET_ENTRY_PEND_COUNT, entry, err
+  );
+  jerry_value_free(err);
+  if(!n) return;
   eventUnsubscribe(&entry->onLoaded, assetEntryOnLoadedFire);
+  eventUnsubscribe(&entry->onError, assetEntryOnErrorFire);
 }
 
 void moduleAssetEntryFree(void *ptr, jerry_object_native_info_t *info) {
@@ -164,9 +138,7 @@ moduleBaseFunction(moduleAssetEntryLoaded) {
   if(!e || !e->entry) {
     return moduleBaseThrow("AssetEntry.loaded: invalid entry");
   }
-
   jerry_value_t promise = jerry_promise();
-
   if(e->entry->state == ASSET_ENTRY_STATE_LOADED) {
     jerry_value_t undef = jerry_undefined();
     jerry_value_t r = jerry_promise_resolve(promise, undef);
@@ -174,7 +146,6 @@ moduleBaseFunction(moduleAssetEntryLoaded) {
     jerry_value_free(r);
     return promise;
   }
-
   if(e->entry->state == ASSET_ENTRY_STATE_ERROR) {
     jerry_value_t err = jerry_string_sz("Asset failed to load");
     jerry_value_t r = jerry_promise_reject(promise, err);
@@ -182,19 +153,13 @@ moduleBaseFunction(moduleAssetEntryLoaded) {
     jerry_value_free(r);
     return promise;
   }
-
-  if(ASSET_ENTRY_LOADED_COUNT >= ASSET_ENTRY_LOADED_MAX) {
+  if(ASSET_ENTRY_PEND_COUNT >= ASSET_ENTRY_PEND_MAX) {
     jerry_value_free(promise);
     return moduleBaseThrow("AssetEntry.loaded: too many pending");
   }
-
-  bool_t subscribed = false;
-  for(uint32_t i = 0; i < ASSET_ENTRY_LOADED_COUNT; i++) {
-    if(ASSET_ENTRY_LOADED[i].entry == e->entry) {
-      subscribed = true; break;
-    }
-  }
-  if(!subscribed) {
+  if(!scriptPromisePendHas(
+      ASSET_ENTRY_PEND, ASSET_ENTRY_PEND_COUNT, e->entry
+  )) {
     eventSubscribe(
       &e->entry->onLoaded, assetEntryOnLoadedFire, e->entry
     );
@@ -202,11 +167,10 @@ moduleBaseFunction(moduleAssetEntryLoaded) {
       &e->entry->onError, assetEntryOnErrorFire, e->entry
     );
   }
-
-  ASSET_ENTRY_LOADED[ASSET_ENTRY_LOADED_COUNT].entry = e->entry;
-  ASSET_ENTRY_LOADED[ASSET_ENTRY_LOADED_COUNT].promise =
-    jerry_value_copy(promise);
-  ASSET_ENTRY_LOADED_COUNT++;
+  scriptPromisePendAdd(
+    ASSET_ENTRY_PEND, &ASSET_ENTRY_PEND_COUNT,
+    ASSET_ENTRY_PEND_MAX, e->entry, promise
+  );
   return promise;
 }
 
@@ -219,7 +183,7 @@ moduleBaseFunction(moduleAssetEntryToString) {
 }
 
 void moduleAssetEntryInit(void) {
-  ASSET_ENTRY_LOADED_COUNT = 0;
+  ASSET_ENTRY_PEND_COUNT = 0;
   scriptProtoInit(
     &MODULE_ASSET_ENTRY_PROTO, "AssetEntry",
     sizeof(jsassetentry_t), moduleAssetEntryCtor
@@ -287,25 +251,19 @@ void moduleAssetEntryInit(void) {
 }
 
 void moduleAssetEntryDispose(void) {
-  for(uint32_t i = 0; i < ASSET_ENTRY_LOADED_COUNT; i++) {
+  for(uint32_t i = 0; i < ASSET_ENTRY_PEND_COUNT; i++) {
     bool_t seen = false;
     for(uint32_t j = 0; j < i; j++) {
-      if(ASSET_ENTRY_LOADED[j].entry == ASSET_ENTRY_LOADED[i].entry) {
+      if(ASSET_ENTRY_PEND[j].key == ASSET_ENTRY_PEND[i].key) {
         seen = true; break;
       }
     }
     if(!seen) {
-      eventUnsubscribe(
-        &ASSET_ENTRY_LOADED[i].entry->onLoaded,
-        assetEntryOnLoadedFire
-      );
-      eventUnsubscribe(
-        &ASSET_ENTRY_LOADED[i].entry->onError,
-        assetEntryOnErrorFire
-      );
+      assetentry_t *e = (assetentry_t *)ASSET_ENTRY_PEND[i].key;
+      eventUnsubscribe(&e->onLoaded, assetEntryOnLoadedFire);
+      eventUnsubscribe(&e->onError, assetEntryOnErrorFire);
     }
-    jerry_value_free(ASSET_ENTRY_LOADED[i].promise);
   }
-  ASSET_ENTRY_LOADED_COUNT = 0;
+  scriptPromisePendFreeAll(ASSET_ENTRY_PEND, &ASSET_ENTRY_PEND_COUNT);
   scriptProtoDispose(&MODULE_ASSET_ENTRY_PROTO);
 }
diff --git a/src/dusk/script/module/asset/moduleassetentry.h b/src/dusk/script/module/asset/moduleassetentry.h
index 3407a2fe..096fae60 100644
--- a/src/dusk/script/module/asset/moduleassetentry.h
+++ b/src/dusk/script/module/asset/moduleassetentry.h
@@ -8,6 +8,7 @@
 #pragma once
 #include "script/module/modulebase.h"
 #include "script/scriptproto.h"
+#include "script/scriptpromisepend.h"
 #include "script/module/display/moduletexture.h"
 #include "script/module/event/moduleevent.h"
 #include "asset/asset.h"
@@ -22,6 +23,24 @@ typedef struct {
   assetentry_t *entry;
 } jsassetentry_t;
 
+/**
+ * Resolves all pending loaded() promises for this entry, then
+ * unsubscribes from both onLoaded and onError.
+ *
+ * @param params Unused.
+ * @param user   The assetentry_t pointer that finished loading.
+ */
+void assetEntryOnLoadedFire(void *params, void *user);
+
+/**
+ * Rejects all pending loaded() promises for this entry, then
+ * unsubscribes from both onLoaded and onError.
+ *
+ * @param params Unused.
+ * @param user   The assetentry_t pointer that errored.
+ */
+void assetEntryOnErrorFire(void *params, void *user);
+
 /**
  * GC free callback - releases the asset lock when the AssetEntry JS object
  * is garbage collected.
diff --git a/src/dusk/script/module/event/moduleevent.c b/src/dusk/script/module/event/moduleevent.c
index a1783e43..058bdfe4 100644
--- a/src/dusk/script/module/event/moduleevent.c
+++ b/src/dusk/script/module/event/moduleevent.c
@@ -11,14 +11,9 @@
 
 #define MODULE_EVENT_PENDING_MAX 32
 
-typedef struct {
-  event_t *event;
-  jerry_value_t promise;
-} moduleeventpending_t;
-
 scriptproto_t MODULE_EVENT_PROTO;
 
-static moduleeventpending_t MODULE_EVENT_PENDING[MODULE_EVENT_PENDING_MAX];
+static scriptpromisepend_t MODULE_EVENT_PENDING[MODULE_EVENT_PENDING_MAX];
 static uint32_t MODULE_EVENT_PENDING_COUNT = 0;
 
 void moduleEventTrampoline0(void *params, void *user) {
@@ -67,29 +62,6 @@ void moduleEventFree(void *ptr, jerry_object_native_info_t *info) {
   memoryFree(ptr);
 }
 
-static void moduleEventWaitFire(void *params, void *user) {
-  event_t *event = (event_t *)user;
-
-  uint32_t i = 0;
-  while(i < MODULE_EVENT_PENDING_COUNT) {
-    if(MODULE_EVENT_PENDING[i].event != event) { i++; continue; }
-    jerry_value_t undef = jerry_undefined();
-    jerry_value_t r = jerry_promise_resolve(
-      MODULE_EVENT_PENDING[i].promise, undef
-    );
-    jerry_value_free(undef);
-    jerry_value_free(r);
-    jerry_value_free(MODULE_EVENT_PENDING[i].promise);
-    MODULE_EVENT_PENDING_COUNT--;
-    if(i < MODULE_EVENT_PENDING_COUNT) {
-      MODULE_EVENT_PENDING[i] =
-        MODULE_EVENT_PENDING[MODULE_EVENT_PENDING_COUNT];
-    }
-  }
-
-  eventUnsubscribe(event, moduleEventWaitFire);
-}
-
 moduleBaseFunction(moduleEventOn) {
   moduleBaseRequireArgs(1);
   jsevent_t *ev = (jsevent_t *)scriptProtoGetValue(
@@ -145,31 +117,24 @@ moduleBaseFunction(moduleEventWait) {
   if(!ev || !ev->event) {
     return moduleBaseThrow("Event.wait: invalid event");
   }
-
   if(MODULE_EVENT_PENDING_COUNT >= MODULE_EVENT_PENDING_MAX) {
     return moduleBaseThrow("Event.wait: too many pending awaits");
   }
-
-  bool_t subscribed = false;
-  for(uint32_t i = 0; i < MODULE_EVENT_PENDING_COUNT; i++) {
-    if(MODULE_EVENT_PENDING[i].event == ev->event) {
-      subscribed = true; break;
-    }
-  }
-  if(!subscribed) {
+  if(!scriptPromisePendHas(
+      MODULE_EVENT_PENDING, MODULE_EVENT_PENDING_COUNT, ev->event
+  )) {
     if(ev->event->count >= ev->event->size) {
       return moduleBaseThrow(
         "Event.wait: event subscriber capacity exceeded"
       );
     }
-    eventSubscribe(ev->event, moduleEventWaitFire, (void *)ev->event);
+    eventSubscribe(ev->event, moduleEventWaitFire, ev->event);
   }
-
   jerry_value_t promise = jerry_promise();
-  MODULE_EVENT_PENDING[MODULE_EVENT_PENDING_COUNT].event = ev->event;
-  MODULE_EVENT_PENDING[MODULE_EVENT_PENDING_COUNT].promise =
-    jerry_value_copy(promise);
-  MODULE_EVENT_PENDING_COUNT++;
+  scriptPromisePendAdd(
+    MODULE_EVENT_PENDING, &MODULE_EVENT_PENDING_COUNT,
+    MODULE_EVENT_PENDING_MAX, ev->event, promise
+  );
   return promise;
 }
 
@@ -203,6 +168,17 @@ jerry_value_t moduleEventGetOrCreate(
   return ev;
 }
 
+void moduleEventWaitFire(void *params, void *user) {
+  event_t *event = (event_t *)user;
+  jerry_value_t undef = jerry_undefined();
+  uint32_t n = scriptPromisePendResolve(
+    MODULE_EVENT_PENDING, &MODULE_EVENT_PENDING_COUNT, event, undef
+  );
+  jerry_value_free(undef);
+  if(!n) return;
+  eventUnsubscribe(event, moduleEventWaitFire);
+}
+
 void moduleEventInit(void) {
   MODULE_EVENT_PENDING_COUNT = 0;
   scriptProtoInit(
@@ -217,19 +193,20 @@ void moduleEventInit(void) {
 
 void moduleEventDispose(void) {
   for(uint32_t i = 0; i < MODULE_EVENT_PENDING_COUNT; i++) {
-    bool_t alreadyUnsub = false;
+    bool_t seen = false;
     for(uint32_t j = 0; j < i; j++) {
-      if(MODULE_EVENT_PENDING[j].event == MODULE_EVENT_PENDING[i].event) {
-        alreadyUnsub = true; break;
+      if(MODULE_EVENT_PENDING[j].key == MODULE_EVENT_PENDING[i].key) {
+        seen = true; break;
       }
     }
-    if(!alreadyUnsub) {
+    if(!seen) {
       eventUnsubscribe(
-        MODULE_EVENT_PENDING[i].event, moduleEventWaitFire
+        (event_t *)MODULE_EVENT_PENDING[i].key, moduleEventWaitFire
       );
     }
-    jerry_value_free(MODULE_EVENT_PENDING[i].promise);
   }
-  MODULE_EVENT_PENDING_COUNT = 0;
+  scriptPromisePendFreeAll(
+    MODULE_EVENT_PENDING, &MODULE_EVENT_PENDING_COUNT
+  );
   scriptProtoDispose(&MODULE_EVENT_PROTO);
 }
diff --git a/src/dusk/script/module/event/moduleevent.h b/src/dusk/script/module/event/moduleevent.h
index 31b3169a..c8012f6c 100644
--- a/src/dusk/script/module/event/moduleevent.h
+++ b/src/dusk/script/module/event/moduleevent.h
@@ -8,6 +8,7 @@
 #pragma once
 #include "script/module/modulebase.h"
 #include "script/scriptproto.h"
+#include "script/scriptpromisepend.h"
 #include "event/event.h"
 
 /** Maximum number of on() subscriber slots per Event. */
@@ -27,6 +28,15 @@ typedef struct {
   jerry_value_t fns[MODULE_EVENT_MAX_SLOTS];
 } jsevent_t;
 
+/**
+ * Event trampoline used by wait(). Resolves all pending wait() promises
+ * for the fired event and unsubscribes itself.
+ *
+ * @param params Unused.
+ * @param user   The event_t pointer that fired.
+ */
+void moduleEventWaitFire(void *params, void *user);
+
 /**
  * GC free callback - unsubscribes all on() slots and releases JS function
  * refs when the Event object is garbage collected.
diff --git a/src/dusk/script/module/modulelist.c b/src/dusk/script/module/modulelist.c
index cb0da584..1a686172 100644
--- a/src/dusk/script/module/modulelist.c
+++ b/src/dusk/script/module/modulelist.c
@@ -28,6 +28,7 @@
 #include "script/module/scene/modulescene.h"
 #include "script/module/story/modulestory.h"
 #include "script/module/system/modulesystem.h"
+#include "script/module/ui/modulefullbox.h"
 #include "script/module/ui/moduletextbox.h"
 
 
@@ -55,6 +56,7 @@ void moduleListInit(void) {
   moduleSceneInit();
   moduleStoryInit();
   moduleSystemInit();
+  moduleFullboxInit();
   moduleTextboxInit();
 }
 
@@ -64,6 +66,7 @@ void moduleListUpdate(void) {
 }
 
 void moduleListDispose(void) {
+  moduleFullboxDispose();
   moduleTextboxDispose();
   moduleSystemDispose();
   moduleOverworldDispose();
diff --git a/src/dusk/script/module/require/modulerequire.c b/src/dusk/script/module/require/modulerequire.c
index 5652f8cf..36956cd5 100644
--- a/src/dusk/script/module/require/modulerequire.c
+++ b/src/dusk/script/module/require/modulerequire.c
@@ -6,18 +6,18 @@
  */
 
 #include "modulerequire.h"
+#include "script/scriptpromisepend.h"
 #include "util/memory.h"
 #include "util/string.h"
 #include "assert/assert.h"
 
-modulerequireasyncpending_t MODULE_REQUIRE_ASYNC_PENDING[
-  MODULE_REQUIRE_ASYNC_MAX
-];
-uint32_t MODULE_REQUIRE_ASYNC_PENDING_COUNT = 0;
+#define MODULE_REQUIRE_ASYNC_MAX 16
+
+static scriptpromisepend_t MODULE_REQUIRE_ASYNC_PEND[MODULE_REQUIRE_ASYNC_MAX];
+static uint32_t MODULE_REQUIRE_ASYNC_PEND_COUNT = 0;
 
 void moduleRequireAsyncOnLoaded(void *params, void *user) {
-  assetentry_t *entry = (assetentry_t *)params;
-
+  assetentry_t *entry = (assetentry_t *)user;
   eventUnsubscribe(&entry->onLoaded, moduleRequireAsyncOnLoaded);
   eventUnsubscribe(&entry->onError, moduleRequireAsyncOnError);
 
@@ -26,66 +26,26 @@ void moduleRequireAsyncOnLoaded(void *params, void *user) {
     jerry_undefined() :
     jerry_value_copy(entry->data.script.exports)
   );
-
-  uint32_t i = 0;
-  while(i < MODULE_REQUIRE_ASYNC_PENDING_COUNT) {
-    if(MODULE_REQUIRE_ASYNC_PENDING[i].entry != entry) {
-      i++;
-      continue;
-    }
-
-    assetUnlockEntry(entry);
-    
-    jerry_value_t copy = jerry_value_copy(exports);
-    jerry_value_t ret = jerry_promise_resolve(
-      MODULE_REQUIRE_ASYNC_PENDING[i].promise, copy
-    );
-    jerry_value_free(ret);
-    jerry_value_free(copy);
-    jerry_value_free(MODULE_REQUIRE_ASYNC_PENDING[i].promise);
-
-    MODULE_REQUIRE_ASYNC_PENDING_COUNT--;
-
-    if(i < MODULE_REQUIRE_ASYNC_PENDING_COUNT) {
-      MODULE_REQUIRE_ASYNC_PENDING[i] = (
-        MODULE_REQUIRE_ASYNC_PENDING[MODULE_REQUIRE_ASYNC_PENDING_COUNT]
-      );
-    }
-  }
-
+  uint32_t n = scriptPromisePendResolve(
+    MODULE_REQUIRE_ASYNC_PEND, &MODULE_REQUIRE_ASYNC_PEND_COUNT,
+    entry, exports
+  );
   jerry_value_free(exports);
+  for(uint32_t i = 0; i < n; i++) assetUnlockEntry(entry);
 }
 
 void moduleRequireAsyncOnError(void *params, void *user) {
-  assetentry_t *entry = (assetentry_t *)params;
-
+  assetentry_t *entry = (assetentry_t *)user;
   eventUnsubscribe(&entry->onLoaded, moduleRequireAsyncOnLoaded);
   eventUnsubscribe(&entry->onError, moduleRequireAsyncOnError);
 
   jerry_value_t errStr = jerry_string_sz("Module load failed");
-
-  uint32_t i = 0;
-  while(i < MODULE_REQUIRE_ASYNC_PENDING_COUNT) {
-    if(MODULE_REQUIRE_ASYNC_PENDING[i].entry != entry) { i++; continue; }
-    assetUnlockEntry(entry);
-    
-    jerry_value_t copy = jerry_value_copy(errStr);
-    jerry_value_t ret = jerry_promise_reject(
-      MODULE_REQUIRE_ASYNC_PENDING[i].promise, copy
-    );
-    jerry_value_free(ret);
-    jerry_value_free(copy);
-    jerry_value_free(MODULE_REQUIRE_ASYNC_PENDING[i].promise);
-    MODULE_REQUIRE_ASYNC_PENDING_COUNT--;
-
-    if(i < MODULE_REQUIRE_ASYNC_PENDING_COUNT) {
-      MODULE_REQUIRE_ASYNC_PENDING[i] = (
-        MODULE_REQUIRE_ASYNC_PENDING[MODULE_REQUIRE_ASYNC_PENDING_COUNT]
-      );
-    }
-  }
-
+  uint32_t n = scriptPromisePendReject(
+    MODULE_REQUIRE_ASYNC_PEND, &MODULE_REQUIRE_ASYNC_PEND_COUNT,
+    entry, errStr
+  );
   jerry_value_free(errStr);
+  for(uint32_t i = 0; i < n; i++) assetUnlockEntry(entry);
 }
 
 jerry_value_t moduleRequireFunc(
@@ -108,7 +68,9 @@ jerry_value_t moduleRequireFunc(
 
   assetloaderinput_t input;
   input.script.nothing = NULL;
-  assetentry_t *entry = assetLock(moduleName, ASSET_LOADER_TYPE_SCRIPT, &input);
+  assetentry_t *entry = assetLock(
+    moduleName, ASSET_LOADER_TYPE_SCRIPT, &input
+  );
 
   errorret_t err = assetRequireLoaded(entry);
   if(errorIsNotOk(err)) {
@@ -137,10 +99,12 @@ jerry_value_t moduleRequireAsyncFunc(
   if(argc < 1 || !jerry_value_is_string(args[0])) {
     return moduleBaseThrow("requireAsync expects a filename string.");
   }
-  if(jerry_string_size(args[0], JERRY_ENCODING_UTF8) >= ASSET_FILE_NAME_MAX) {
+  if(
+    jerry_string_size(args[0], JERRY_ENCODING_UTF8) >= ASSET_FILE_NAME_MAX
+  ) {
     return moduleBaseThrow("Module name too long.");
   }
-  if(MODULE_REQUIRE_ASYNC_PENDING_COUNT >= MODULE_REQUIRE_ASYNC_MAX) {
+  if(MODULE_REQUIRE_ASYNC_PEND_COUNT >= MODULE_REQUIRE_ASYNC_MAX) {
     return moduleBaseThrow("Too many pending requireAsync calls.");
   }
 
@@ -149,11 +113,12 @@ jerry_value_t moduleRequireAsyncFunc(
 
   assetloaderinput_t input;
   input.script.nothing = NULL;
-  assetentry_t *entry = assetLock(moduleName, ASSET_LOADER_TYPE_SCRIPT, &input);
+  assetentry_t *entry = assetLock(
+    moduleName, ASSET_LOADER_TYPE_SCRIPT, &input
+  );
 
   jerry_value_t promise = jerry_promise();
 
-  // Already loaded - resolve immediately.
   if(entry->state == ASSET_ENTRY_STATE_LOADED) {
     jerry_value_t exports = (
       jerry_value_is_undefined(entry->data.script.exports) ?
@@ -167,7 +132,6 @@ jerry_value_t moduleRequireAsyncFunc(
     return promise;
   }
 
-  // Already errored - reject immediately.
   if(entry->state == ASSET_ENTRY_STATE_ERROR) {
     assetUnlockEntry(entry);
     jerry_value_t errStr = jerry_string_sz("Module load failed");
@@ -177,62 +141,56 @@ jerry_value_t moduleRequireAsyncFunc(
     return promise;
   }
 
-  // Subscribe to entry events only if this is the first pending await for it.
-  bool_t subscribed = false;
-  for(uint32_t i = 0; i < MODULE_REQUIRE_ASYNC_PENDING_COUNT; i++) {
-    if(MODULE_REQUIRE_ASYNC_PENDING[i].entry == entry) {
-      subscribed = true;
-      break;
-    }
-  }
-
-  if(!subscribed) {
+  if(!scriptPromisePendHas(
+      MODULE_REQUIRE_ASYNC_PEND, MODULE_REQUIRE_ASYNC_PEND_COUNT, entry
+  )) {
     if(entry->onLoaded.count >= entry->onLoaded.size) {
       assetUnlockEntry(entry);
       jerry_value_free(promise);
-      return moduleBaseThrow("requireAsync: onLoaded event capacity exceeded.");
+      return moduleBaseThrow(
+        "requireAsync: onLoaded event capacity exceeded."
+      );
     }
     if(entry->onError.count >= entry->onError.size) {
       assetUnlockEntry(entry);
       jerry_value_free(promise);
-      return moduleBaseThrow("requireAsync: onError event capacity exceeded.");
+      return moduleBaseThrow(
+        "requireAsync: onError event capacity exceeded."
+      );
     }
-    eventSubscribe(&entry->onLoaded, moduleRequireAsyncOnLoaded, NULL);
-    eventSubscribe(&entry->onError, moduleRequireAsyncOnError, NULL);
+    eventSubscribe(&entry->onLoaded, moduleRequireAsyncOnLoaded, entry);
+    eventSubscribe(&entry->onError, moduleRequireAsyncOnError, entry);
   }
 
-  MODULE_REQUIRE_ASYNC_PENDING[MODULE_REQUIRE_ASYNC_PENDING_COUNT].entry = (
-    entry
+  scriptPromisePendAdd(
+    MODULE_REQUIRE_ASYNC_PEND, &MODULE_REQUIRE_ASYNC_PEND_COUNT,
+    MODULE_REQUIRE_ASYNC_MAX, entry, promise
   );
-  MODULE_REQUIRE_ASYNC_PENDING[MODULE_REQUIRE_ASYNC_PENDING_COUNT].promise = (
-    jerry_value_copy(promise)
-  );
-  MODULE_REQUIRE_ASYNC_PENDING_COUNT++;
   return promise;
 }
 
 void moduleRequireInit(void) {
-  MODULE_REQUIRE_ASYNC_PENDING_COUNT = 0;
+  MODULE_REQUIRE_ASYNC_PEND_COUNT = 0;
   moduleBaseDefineGlobalMethod("require", moduleRequireFunc);
   moduleBaseDefineGlobalMethod("requireAsync", moduleRequireAsyncFunc);
 }
 
 void moduleRequireDispose(void) {
-  for(uint32_t i = 0; i < MODULE_REQUIRE_ASYNC_PENDING_COUNT; i++) {
-    assetentry_t *entry = MODULE_REQUIRE_ASYNC_PENDING[i].entry;
-    bool_t alreadyUnsub = false;
+  for(uint32_t i = 0; i < MODULE_REQUIRE_ASYNC_PEND_COUNT; i++) {
+    assetentry_t *e = (assetentry_t *)MODULE_REQUIRE_ASYNC_PEND[i].key;
+    bool_t seen = false;
     for(uint32_t j = 0; j < i; j++) {
-      if(MODULE_REQUIRE_ASYNC_PENDING[j].entry == entry) {
-        alreadyUnsub = true;
-        break;
+      if(MODULE_REQUIRE_ASYNC_PEND[j].key == e) {
+        seen = true; break;
       }
     }
-    if(!alreadyUnsub) {
-      eventUnsubscribe(&entry->onLoaded, moduleRequireAsyncOnLoaded);
-      eventUnsubscribe(&entry->onError, moduleRequireAsyncOnError);
+    if(!seen) {
+      eventUnsubscribe(&e->onLoaded, moduleRequireAsyncOnLoaded);
+      eventUnsubscribe(&e->onError, moduleRequireAsyncOnError);
     }
-    assetUnlockEntry(entry);
-    jerry_value_free(MODULE_REQUIRE_ASYNC_PENDING[i].promise);
+    assetUnlockEntry(e);
   }
-  MODULE_REQUIRE_ASYNC_PENDING_COUNT = 0;
+  scriptPromisePendFreeAll(
+    MODULE_REQUIRE_ASYNC_PEND, &MODULE_REQUIRE_ASYNC_PEND_COUNT
+  );
 }
diff --git a/src/dusk/script/module/require/modulerequire.h b/src/dusk/script/module/require/modulerequire.h
index ef3445d4..4bf5a576 100644
--- a/src/dusk/script/module/require/modulerequire.h
+++ b/src/dusk/script/module/require/modulerequire.h
@@ -9,19 +9,6 @@
 #include "script/module/modulebase.h"
 #include "asset/asset.h"
 
-#define MODULE_REQUIRE_ASYNC_MAX 16
-
-typedef struct {
-  assetentry_t *entry;
-  jerry_value_t promise;
-} modulerequireasyncpending_t;
-
-extern modulerequireasyncpending_t MODULE_REQUIRE_ASYNC_PENDING[
-  MODULE_REQUIRE_ASYNC_MAX
-];
-
-extern uint32_t MODULE_REQUIRE_ASYNC_PENDING_COUNT;
-
 /**
  * Success loaded callback for async module loading.
  * 
diff --git a/src/dusk/script/module/ui/CMakeLists.txt b/src/dusk/script/module/ui/CMakeLists.txt
index a22320cb..d2884254 100644
--- a/src/dusk/script/module/ui/CMakeLists.txt
+++ b/src/dusk/script/module/ui/CMakeLists.txt
@@ -5,5 +5,6 @@
 
 target_sources(${DUSK_LIBRARY_TARGET_NAME}
   PUBLIC
+    modulefullbox.c
     moduletextbox.c
 )
diff --git a/src/dusk/script/module/ui/modulefullbox.c b/src/dusk/script/module/ui/modulefullbox.c
new file mode 100644
index 00000000..85d15bd1
--- /dev/null
+++ b/src/dusk/script/module/ui/modulefullbox.c
@@ -0,0 +1,150 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "modulefullbox.h"
+#include "script/scriptpromisepend.h"
+#include "script/module/display/modulecolor.h"
+#include "animation/easing.h"
+
+#define MODULE_FULLBOX_PEND_MAX 8
+
+typedef struct {
+  uifullbox_t *fullbox;
+} jsuifullbox_t;
+
+scriptproto_t MODULE_FULLBOX_PROTO;
+
+static scriptpromisepend_t MODULE_FULLBOX_PEND[MODULE_FULLBOX_PEND_MAX];
+static uint32_t MODULE_FULLBOX_PEND_COUNT = 0;
+
+moduleBaseFunction(moduleFullboxSetColor) {
+  moduleBaseRequireArgs(1);
+  jsuifullbox_t *d = (jsuifullbox_t *)scriptProtoGetValue(
+    &MODULE_FULLBOX_PROTO, callInfo->this_value
+  );
+  if(!d || !d->fullbox) return jerry_undefined();
+  color_t *c = moduleColorFrom(args[0]);
+  if(!c) return jerry_undefined();
+  moduleFullboxTransitionFire(NULL, d->fullbox);
+  uiFullboxTransition(d->fullbox, *c, *c, 0.0f, EASING_LINEAR);
+  jerry_value_t promise = jerry_promise();
+  jerry_value_t undef = jerry_undefined();
+  jerry_value_t r = jerry_promise_resolve(promise, undef);
+  jerry_value_free(undef);
+  jerry_value_free(r);
+  return promise;
+}
+
+moduleBaseFunction(moduleFullboxTransition) {
+  moduleBaseRequireArgs(3);
+  jsuifullbox_t *d = (jsuifullbox_t *)scriptProtoGetValue(
+    &MODULE_FULLBOX_PROTO, callInfo->this_value
+  );
+  if(!d || !d->fullbox) return jerry_undefined();
+  color_t *from = moduleColorFrom(args[0]);
+  color_t *to = moduleColorFrom(args[1]);
+  if(!from || !to) return jerry_undefined();
+  float_t duration = moduleBaseArgFloat(2);
+  easingtype_t easing = (easingtype_t)moduleBaseOptInt(
+    3, (int32_t)EASING_LINEAR
+  );
+  moduleFullboxTransitionFire(NULL, d->fullbox);
+  uiFullboxTransition(d->fullbox, *from, *to, duration, easing);
+  jerry_value_t promise = jerry_promise();
+  if(duration <= 0.0f) {
+    jerry_value_t undef = jerry_undefined();
+    jerry_value_t r = jerry_promise_resolve(promise, undef);
+    jerry_value_free(undef);
+    jerry_value_free(r);
+    return promise;
+  }
+  if(MODULE_FULLBOX_PEND_COUNT >= MODULE_FULLBOX_PEND_MAX) {
+    jerry_value_t errStr = jerry_string_sz(
+      "UIFullbox.transition: too many pending"
+    );
+    jerry_value_t r = jerry_promise_reject(promise, errStr);
+    jerry_value_free(errStr);
+    jerry_value_free(r);
+    return promise;
+  }
+  if(!scriptPromisePendHas(
+      MODULE_FULLBOX_PEND, MODULE_FULLBOX_PEND_COUNT, d->fullbox
+  )) {
+    eventSubscribe(
+      &d->fullbox->onTransitionEnd,
+      moduleFullboxTransitionFire,
+      d->fullbox
+    );
+  }
+  scriptPromisePendAdd(
+    MODULE_FULLBOX_PEND, &MODULE_FULLBOX_PEND_COUNT,
+    MODULE_FULLBOX_PEND_MAX, d->fullbox, promise
+  );
+  return promise;
+}
+
+void moduleFullboxTransitionFire(void *params, void *user) {
+  uifullbox_t *fullbox = (uifullbox_t *)user;
+  jerry_value_t undef = jerry_undefined();
+  uint32_t n = scriptPromisePendResolve(
+    MODULE_FULLBOX_PEND, &MODULE_FULLBOX_PEND_COUNT, fullbox, undef
+  );
+  jerry_value_free(undef);
+  if(!n) return;
+  eventUnsubscribe(
+    &fullbox->onTransitionEnd, moduleFullboxTransitionFire
+  );
+}
+
+void moduleFullboxInit(void) {
+  MODULE_FULLBOX_PEND_COUNT = 0;
+  scriptProtoInit(
+    &MODULE_FULLBOX_PROTO, NULL, sizeof(jsuifullbox_t), NULL
+  );
+
+  scriptProtoDefineFunc(
+    &MODULE_FULLBOX_PROTO, "setColor", moduleFullboxSetColor
+  );
+  scriptProtoDefineFunc(
+    &MODULE_FULLBOX_PROTO, "transition", moduleFullboxTransition
+  );
+
+  jsuifullbox_t over = { .fullbox = &UI_FULLBOX_OVER };
+  jerry_value_t overVal = scriptProtoCreateValue(
+    &MODULE_FULLBOX_PROTO, &over
+  );
+  moduleBaseSetValue("UIFullboxOver", overVal);
+  jerry_value_free(overVal);
+
+  jsuifullbox_t under = { .fullbox = &UI_FULLBOX_UNDER };
+  jerry_value_t underVal = scriptProtoCreateValue(
+    &MODULE_FULLBOX_PROTO, &under
+  );
+  moduleBaseSetValue("UIFullboxUnder", underVal);
+  jerry_value_free(underVal);
+}
+
+void moduleFullboxDispose(void) {
+  for(uint32_t i = 0; i < MODULE_FULLBOX_PEND_COUNT; i++) {
+    bool_t seen = false;
+    for(uint32_t j = 0; j < i; j++) {
+      if(MODULE_FULLBOX_PEND[j].key == MODULE_FULLBOX_PEND[i].key) {
+        seen = true; break;
+      }
+    }
+    if(!seen) {
+      uifullbox_t *fb = (uifullbox_t *)MODULE_FULLBOX_PEND[i].key;
+      eventUnsubscribe(
+        &fb->onTransitionEnd, moduleFullboxTransitionFire
+      );
+    }
+  }
+  scriptPromisePendFreeAll(
+    MODULE_FULLBOX_PEND, &MODULE_FULLBOX_PEND_COUNT
+  );
+  scriptProtoDispose(&MODULE_FULLBOX_PROTO);
+}
diff --git a/src/dusk/script/module/ui/modulefullbox.h b/src/dusk/script/module/ui/modulefullbox.h
new file mode 100644
index 00000000..dbd320c9
--- /dev/null
+++ b/src/dusk/script/module/ui/modulefullbox.h
@@ -0,0 +1,54 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "script/module/modulebase.h"
+#include "script/scriptproto.h"
+#include "ui/uifullbox.h"
+
+extern scriptproto_t MODULE_FULLBOX_PROTO;
+
+/**
+ * Event trampoline that resolves all pending transition promises for a
+ * fullbox and unsubscribes from onTransitionEnd. Also called directly
+ * to flush promises when a new transition interrupts a running one.
+ *
+ * @param params Unused (receives the uifullbox_t from eventInvoke).
+ * @param user   The uifullbox_t pointer whose transition completed.
+ */
+void moduleFullboxTransitionFire(void *params, void *user);
+
+/**
+ * setColor(color) - instantly sets the fullbox to a solid color.
+ * Returns a Promise that resolves immediately.
+ *
+ * @param args[0] Color instance.
+ */
+moduleBaseFunction(moduleFullboxSetColor);
+
+/**
+ * transition(from, to, duration, easing?) - animates the fullbox from
+ * one color to another. Returns a Promise that resolves when the
+ * transition completes.
+ *
+ * @param args[0] Starting Color.
+ * @param args[1] Ending Color.
+ * @param args[2] Duration in seconds.
+ * @param args[3] Optional EASING_* constant (default: EASING_LINEAR).
+ */
+moduleBaseFunction(moduleFullboxTransition);
+
+/**
+ * Initializes the UIFullbox module, registering UIFullboxOver and
+ * UIFullboxUnder as global singleton objects.
+ */
+void moduleFullboxInit(void);
+
+/**
+ * Disposes the UIFullbox module.
+ */
+void moduleFullboxDispose(void);
diff --git a/src/dusk/script/scriptpromisepend.c b/src/dusk/script/scriptpromisepend.c
new file mode 100644
index 00000000..0559ca51
--- /dev/null
+++ b/src/dusk/script/scriptpromisepend.c
@@ -0,0 +1,83 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "scriptpromisepend.h"
+#include "assert/assert.h"
+
+uint32_t scriptPromisePendResolve(
+  scriptpromisepend_t *pend,
+  uint32_t *count,
+  const void *key,
+  jerry_value_t value
+) {
+  uint32_t resolved = 0;
+  uint32_t i = 0;
+  while(i < *count) {
+    if(pend[i].key != key) { i++; continue; }
+    jerry_value_t r = jerry_promise_resolve(pend[i].promise, value);
+    jerry_value_free(r);
+    jerry_value_free(pend[i].promise);
+    (*count)--;
+    if(i < *count) pend[i] = pend[*count];
+    resolved++;
+  }
+  return resolved;
+}
+
+uint32_t scriptPromisePendReject(
+  scriptpromisepend_t *pend,
+  uint32_t *count,
+  const void *key,
+  jerry_value_t error
+) {
+  uint32_t rejected = 0;
+  uint32_t i = 0;
+  while(i < *count) {
+    if(pend[i].key != key) { i++; continue; }
+    jerry_value_t r = jerry_promise_reject(pend[i].promise, error);
+    jerry_value_free(r);
+    jerry_value_free(pend[i].promise);
+    (*count)--;
+    if(i < *count) pend[i] = pend[*count];
+    rejected++;
+  }
+  return rejected;
+}
+
+bool_t scriptPromisePendHas(
+  const scriptpromisepend_t *pend,
+  uint32_t count,
+  const void *key
+) {
+  for(uint32_t i = 0; i < count; i++) {
+    if(pend[i].key == key) return true;
+  }
+  return false;
+}
+
+void scriptPromisePendAdd(
+  scriptpromisepend_t *pend,
+  uint32_t *count,
+  uint32_t max,
+  const void *key,
+  jerry_value_t promise
+) {
+  assertTrue(*count < max, "scriptPromisePendAdd: capacity exceeded");
+  pend[*count].key = (void *)key;
+  pend[*count].promise = jerry_value_copy(promise);
+  (*count)++;
+}
+
+void scriptPromisePendFreeAll(
+  scriptpromisepend_t *pend,
+  uint32_t *count
+) {
+  for(uint32_t i = 0; i < *count; i++) {
+    jerry_value_free(pend[i].promise);
+  }
+  *count = 0;
+}
diff --git a/src/dusk/script/scriptpromisepend.h b/src/dusk/script/scriptpromisepend.h
new file mode 100644
index 00000000..c6df046f
--- /dev/null
+++ b/src/dusk/script/scriptpromisepend.h
@@ -0,0 +1,98 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "dusk.h"
+#include <jerryscript.h>
+
+/**
+ * One pending promise keyed to a pointer.
+ * Declare a static array of these in each script module that needs to
+ * wait on a C event before resolving a JS promise.
+ */
+typedef struct {
+  void *key;
+  jerry_value_t promise;
+} scriptpromisepend_t;
+
+/**
+ * Resolves all entries whose key matches and swap-removes them.
+ * Returns the number of promises resolved.
+ *
+ * @param pend   The pending array.
+ * @param count  Current count (updated in place).
+ * @param key    Key to match.
+ * @param value  Value passed to jerry_promise_resolve.
+ * @return Number of promises resolved.
+ */
+uint32_t scriptPromisePendResolve(
+  scriptpromisepend_t *pend,
+  uint32_t *count,
+  const void *key,
+  jerry_value_t value
+);
+
+/**
+ * Rejects all entries whose key matches and swap-removes them.
+ * Returns the number of promises rejected.
+ *
+ * @param pend   The pending array.
+ * @param count  Current count (updated in place).
+ * @param key    Key to match.
+ * @param error  Reason passed to jerry_promise_reject.
+ * @return Number of promises rejected.
+ */
+uint32_t scriptPromisePendReject(
+  scriptpromisepend_t *pend,
+  uint32_t *count,
+  const void *key,
+  jerry_value_t error
+);
+
+/**
+ * Returns true if any entry has key equal to key.
+ *
+ * @param pend   The pending array.
+ * @param count  Current count.
+ * @param key    Key to search for.
+ * @return true if found.
+ */
+bool_t scriptPromisePendHas(
+  const scriptpromisepend_t *pend,
+  uint32_t count,
+  const void *key
+);
+
+/**
+ * Appends a new entry. Stores a copy of the promise; the caller keeps
+ * the original to return to script. Asserts that count < max.
+ *
+ * @param pend    The pending array.
+ * @param count   Current count (incremented in place).
+ * @param max     Capacity of the array.
+ * @param key     Key to associate with the promise.
+ * @param promise Promise to copy into the array.
+ */
+void scriptPromisePendAdd(
+  scriptpromisepend_t *pend,
+  uint32_t *count,
+  uint32_t max,
+  const void *key,
+  jerry_value_t promise
+);
+
+/**
+ * Frees all stored promise references without resolving them, then
+ * zeros count. Call during module dispose before cleaning up events.
+ *
+ * @param pend  The pending array.
+ * @param count Current count (set to 0).
+ */
+void scriptPromisePendFreeAll(
+  scriptpromisepend_t *pend,
+  uint32_t *count
+);
diff --git a/src/dusk/ui/ui.c b/src/dusk/ui/ui.c
index 83416495..6310ee13 100644
--- a/src/dusk/ui/ui.c
+++ b/src/dusk/ui/ui.c
@@ -20,6 +20,8 @@ ui_t UI;
 
 errorret_t uiInit(void) {
   memoryZero(&UI, sizeof(ui_t));
+  uiFullboxInit(&UI_FULLBOX_UNDER);
+  uiFullboxInit(&UI_FULLBOX_OVER);
   uiLoadingInit();
 
   uielement_t *element = &UI_ELEMENTS[0];
diff --git a/src/dusk/ui/uielement.c b/src/dusk/ui/uielement.c
index fc1266ef..a5c156d6 100644
--- a/src/dusk/ui/uielement.c
+++ b/src/dusk/ui/uielement.c
@@ -20,14 +20,17 @@ uielement_t UI_ELEMENTS[] = {
 
   // { .type = UI_ELEMENT_TYPE_SCRIPT, .script = { .script = "ui/test.js" } },
 
-  { .type = UI_ELEMENT_TYPE_NATIVE, .draw = consoleDraw },
   { .type = UI_ELEMENT_TYPE_NATIVE, .draw = uiTextboxDraw },
   // Fullbox over: above absolutely everything.
   { .type = UI_ELEMENT_TYPE_NATIVE, .draw = uiFullboxOverDraw },
+
+
   // These render above the fullbox overlay.
+  { .type = UI_ELEMENT_TYPE_NATIVE, .draw = consoleDraw },
   { .type = UI_ELEMENT_TYPE_NATIVE, .draw = uiFPSDraw },
   { .type = UI_ELEMENT_TYPE_NATIVE, .draw = uiLoadingDraw },
 
+
   { .type = UI_ELEMENT_TYPE_NULL },
 };
 
diff --git a/types/index.d.ts b/types/index.d.ts
index a5bd131f..e2d0edf4 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -51,6 +51,7 @@
 /// <reference path="./save/save.d.ts" />
 
 // ui
+/// <reference path="./ui/fullbox.d.ts" />
 /// <reference path="./ui/textbox.d.ts" />
 
 // engine systems
diff --git a/types/ui/fullbox.d.ts b/types/ui/fullbox.d.ts
new file mode 100644
index 00000000..2082f9d4
--- /dev/null
+++ b/types/ui/fullbox.d.ts
@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+/** A full-screen color overlay. */
+interface UIFullboxInstance {
+  /**
+   * Sets the overlay to a solid color with no animation.
+   * Returns a Promise that resolves immediately.
+   * @param color - The color to apply.
+   */
+  setColor(color: Color): Promise<void>;
+
+  /**
+   * Animates the overlay from one color to another.
+   * Returns a Promise that resolves when the transition completes.
+   * Starting a new transition while one is in progress resolves the
+   * old Promise immediately before beginning the new one.
+   * @param from     - Starting color.
+   * @param to       - Ending color.
+   * @param duration - Duration in seconds.
+   * @param easing   - Optional EASING_* constant (default: EASING_LINEAR).
+   */
+  transition(
+    from: Color,
+    to: Color,
+    duration: number,
+    easing?: number
+  ): Promise<void>;
+}
+
+/** Full-screen overlay drawn on top of all UI elements. */
+declare var UIFullboxOver: UIFullboxInstance;
+
+/** Full-screen overlay drawn below all UI elements. */
+declare var UIFullboxUnder: UIFullboxInstance;