Shader first pass

assets/scene/minesweeper.lua

@@ -192,7 +192,7 @@ function sceneRender()
   spriteBatchPush(
     nil,
     x, y, x + 32, y + 32,
-    colorBlue()
+    colorWhite()
   )
 
   -- Update mouse position

cmake/targets/linux.cmake

@@ -30,6 +30,7 @@ target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
   DUSK_OPENGL
   DUSK_LINUX
   DUSK_DISPLAY_SIZE_DYNAMIC
+  DUSK_OPENGL_SHADER
   DUSK_DISPLAY_WIDTH_DEFAULT=640
   DUSK_DISPLAY_HEIGHT_DEFAULT=480
   DUSK_DISPLAY_SCREEN_HEIGHT=240

src/dusk/display/CMakeLists.txt

@@ -14,6 +14,7 @@ add_subdirectory(camera)
 add_subdirectory(framebuffer)
 add_subdirectory(mesh)
 add_subdirectory(screen)
+add_subdirectory(shader)
 add_subdirectory(spritebatch)
 add_subdirectory(text)
 add_subdirectory(texture)

src/dusk/display/display.c

@@ -46,16 +46,16 @@ errorret_t displayUpdate(void) {
   errorChain(frameBufferBind(NULL));
   
   // Bind screen and render scene
-  screenBind();
+  errorChain(screenBind());
   frameBufferClear(
     FRAMEBUFFER_CLEAR_COLOR | FRAMEBUFFER_CLEAR_DEPTH,
     SCREEN.background
   );
 
-  errorChain(sceneRender());
+  errorCatch(errorPrint(sceneRender()));
 
   // Render UI
-  uiRender();
+  // uiRender();
 
   // Finish up
   screenUnbind();

src/dusk/display/screen/screen.c

@@ -44,11 +44,11 @@ errorret_t screenInit() {
   #endif
 
   // Init screen to backbuffer mode by default
-  screenBind();
+  errorChain(screenBind());
   errorOk();
 }
 
-void screenBind() {
+errorret_t screenBind() {
   // Assume backbuffer is currently bound.
   switch(SCREEN.mode) {
     case SCREEN_MODE_BACKBUFFER: {
@@ -59,7 +59,7 @@ void screenBind() {
       // No needd for a framebuffer.
       #ifdef DUSK_DISPLAY_SIZE_DYNAMIC
         if(SCREEN.framebufferReady) {
-          frameBufferDispose(&SCREEN.framebuffer);
+          errorChain(frameBufferDispose(&SCREEN.framebuffer));
           SCREEN.framebufferReady = false;
         }
       #endif
@@ -79,19 +79,21 @@ void screenBind() {
           curFbHeight = frameBufferGetHeight(&SCREEN.framebuffer);
           if(curFbWidth == SCREEN.width && curFbHeight == SCREEN.height) {
             // Correct size, nothing to do.
-            frameBufferBind(&SCREEN.framebuffer);
+            errorChain(frameBufferBind(&SCREEN.framebuffer));
-            return;
+            errorOk();
           }
 
           // Need a new framebuffer.
-          frameBufferDispose(&SCREEN.framebuffer);
+          errorChain(frameBufferDispose(&SCREEN.framebuffer));
           SCREEN.framebufferReady = false;
         }
 
         // Create new framebuffer
-        frameBufferInit(&SCREEN.framebuffer, SCREEN.width, SCREEN.height);
+        errorChain(frameBufferInit(
+          &SCREEN.framebuffer, SCREEN.width, SCREEN.height
+        ));
         SCREEN.framebufferReady = true;
-        frameBufferBind(&SCREEN.framebuffer);
+        errorChain(frameBufferBind(&SCREEN.framebuffer));
         break;
       }
 
@@ -109,10 +111,10 @@ void screenBind() {
           SCREEN.aspect = (float_t)SCREEN.width / (float_t)SCREEN.height;
 
           if(SCREEN.framebufferReady) {
-            frameBufferDispose(&SCREEN.framebuffer);
+            errorChain(frameBufferDispose(&SCREEN.framebuffer));
             SCREEN.framebufferReady = false;
           }
-          return;
+          errorOk();
         }
 
         int32_t newFbWidth, newFbHeight;
@@ -136,24 +138,26 @@ void screenBind() {
             SCREEN.width = newFbWidth;
             SCREEN.height = newFbHeight;
             SCREEN.aspect = (float_t)SCREEN.width / (float_t)SCREEN.height;
-            frameBufferBind(&SCREEN.framebuffer);
+            errorChain(frameBufferBind(&SCREEN.framebuffer));
-            return;
+            errorOk();
           }
 
           // Need a new framebuffer.
-          frameBufferDispose(&SCREEN.framebuffer);
+          errorChain(frameBufferDispose(&SCREEN.framebuffer));
           SCREEN.framebufferReady = false;
         }
 
         // Create new framebuffer
-        frameBufferInit(&SCREEN.framebuffer, newFbWidth, newFbHeight);
+        errorChain(frameBufferInit(
+          &SCREEN.framebuffer, newFbWidth, newFbHeight
+        ));
         SCREEN.width = newFbWidth;
         SCREEN.height = newFbHeight;
         SCREEN.aspect = (float_t)SCREEN.width / (float_t)SCREEN.height;
         SCREEN.framebufferReady = true;
 
         // Bind FB
-        frameBufferBind(&SCREEN.framebuffer);
+        errorChain(frameBufferBind(&SCREEN.framebuffer));
         break;
       }
 
@@ -173,10 +177,10 @@ void screenBind() {
         if(fbWidth == newFbWidth && fbHeight == newFbHeight) {
           // No need to use framebuffer.
           if(SCREEN.framebufferReady) {
-            frameBufferDispose(&SCREEN.framebuffer);
+            errorChain(frameBufferDispose(&SCREEN.framebuffer));
             SCREEN.framebufferReady = false;
           }
-          return;
+          errorOk();
         }
 
         if(SCREEN.framebufferReady) {
@@ -185,19 +189,21 @@ void screenBind() {
           curFbWidth = frameBufferGetWidth(&SCREEN.framebuffer);
           curFbHeight = frameBufferGetHeight(&SCREEN.framebuffer);
           if(curFbWidth == newFbWidth && curFbHeight == newFbHeight) {
-            frameBufferBind(&SCREEN.framebuffer);
+            errorChain(frameBufferBind(&SCREEN.framebuffer));
-            return;
+            errorOk();
           }
 
           // Need a new framebuffer.
-          frameBufferDispose(&SCREEN.framebuffer);
+          errorChain(frameBufferDispose(&SCREEN.framebuffer));
           SCREEN.framebufferReady = false;
         }
 
         // Create a new framebuffer.
-        frameBufferInit(&SCREEN.framebuffer, newFbWidth, newFbHeight);
+        errorChain(frameBufferInit(
+          &SCREEN.framebuffer, newFbWidth, newFbHeight
+        ));
         SCREEN.framebufferReady = true;
-        frameBufferBind(&SCREEN.framebuffer);
+        errorChain(frameBufferBind(&SCREEN.framebuffer));
         break;
       }
 
@@ -217,10 +223,10 @@ void screenBind() {
         if(fbWidth == newFbWidth && fbHeight == newFbHeight) {
           // No need to use framebuffer.
           if(SCREEN.framebufferReady) {
-            frameBufferDispose(&SCREEN.framebuffer);
+            errorChain(frameBufferDispose(&SCREEN.framebuffer));
             SCREEN.framebufferReady = false;
           }
-          return;
+          errorOk();
         }
 
         if(SCREEN.framebufferReady) {
@@ -229,19 +235,21 @@ void screenBind() {
           curFbWidth = frameBufferGetWidth(&SCREEN.framebuffer);
           curFbHeight = frameBufferGetHeight(&SCREEN.framebuffer);
           if(curFbWidth == newFbWidth && curFbHeight == newFbHeight) {
-            frameBufferBind(&SCREEN.framebuffer);
+            errorChain(frameBufferBind(&SCREEN.framebuffer));
-            return;
+            errorOk();
           }
 
           // Need a new framebuffer.
-          frameBufferDispose(&SCREEN.framebuffer);
+          errorChain(frameBufferDispose(&SCREEN.framebuffer));
           SCREEN.framebufferReady = false;
         }
 
         // Create a new framebuffer.
-        frameBufferInit(&SCREEN.framebuffer, newFbWidth, newFbHeight);
+        errorChain(frameBufferInit(
+          &SCREEN.framebuffer, newFbWidth, newFbHeight
+        ));
         SCREEN.framebufferReady = true;
-        frameBufferBind(&SCREEN.framebuffer);
+        errorChain(frameBufferBind(&SCREEN.framebuffer));
         break;
       }
 
@@ -262,9 +270,11 @@ void screenBind() {
       break;
     }
   }
+
+  errorOk();
 }
 
-void screenUnbind() {
+errorret_t screenUnbind() {
   switch(SCREEN.mode) {
     // Nothing to do here.
     case SCREEN_MODE_BACKBUFFER:
@@ -275,7 +285,9 @@ void screenUnbind() {
       case SCREEN_MODE_FIXED_HEIGHT:
       case SCREEN_MODE_FIXED_SIZE:
       case SCREEN_MODE_FIXED_WIDTH:
-        if(SCREEN.framebufferReady) frameBufferBind(NULL);
+        if(SCREEN.framebufferReady) {
+          errorChain(frameBufferBind(NULL));
+        }
         break;
 
       case SCREEN_MODE_FIXED_VIEWPORT_HEIGHT:
@@ -286,17 +298,19 @@ void screenUnbind() {
       assertUnreachable("Invalid screen mode.");
       break;
   }
+
+  errorOk();
 }
 
-void screenRender() {
+errorret_t screenRender() {
   if(SCREEN.mode == SCREEN_MODE_BACKBUFFER) {
-    return;
+    errorOk();
   }
 
   #ifdef DUSK_DISPLAY_SIZE_DYNAMIC
     if(SCREEN.mode == SCREEN_MODE_FIXED_VIEWPORT_HEIGHT) {
       glViewport(0, 0, SCREEN.width, SCREEN.height);
-      return;
+      errorOk();
     }
 
     if(
@@ -307,7 +321,7 @@ void screenRender() {
     ) {
       if(!SCREEN.framebufferReady) {
         // Nothing to do here.
-        return;
+        errorOk();
       }
 
       float_t bbWidth, bbHeight;
@@ -357,22 +371,25 @@ void screenRender() {
         COLOR_BLACK
       );
       cameraPushMatrix(&SCREEN.framebufferCamera);
-      textureBind(&SCREEN.framebuffer.texture);
+      errorChain(textureBind(&SCREEN.framebuffer.texture));
-      meshDraw(&SCREEN.frameBufferMesh, 0, -1);
+      errorChain(meshDraw(&SCREEN.frameBufferMesh, 0, -1));
       cameraPopMatrix();
 
-      return;
+      errorOk();
     };
   #endif
 
   assertUnreachable("Invalid screen mode.");
+  errorThrow("Invalid screen mode.");
 }
 
-void screenDispose() {
+errorret_t screenDispose() {
   #ifdef DUSK_DISPLAY_SIZE_DYNAMIC
     if(SCREEN.framebufferReady) {
-      frameBufferDispose(&SCREEN.framebuffer);
+      errorChain(frameBufferDispose(&SCREEN.framebuffer));
       SCREEN.framebufferReady = false;
     }
   #endif
+
+  errorOk();
 }

src/dusk/display/screen/screen.h

@@ -90,20 +90,28 @@ errorret_t screenInit();
 
 /**
  * Binds the screen, this is done before rendering game content.
+ * 
+ * @return Error code and state, if error occurs.
  */
-void screenBind();
+errorret_t screenBind();
 
 /**
  * Unbinds the screen, does nothing for now.
+ * 
+ * @return Error code and state, if error occurs.
  */
-void screenUnbind();
+errorret_t screenUnbind();
 
 /**
  * Renders the screen to the current framebuffer.
+ * 
+ * @return Error code and state, if error occurs.
  */
-void screenRender();
+errorret_t screenRender();
 
 /**
  * Disposes the screen system.
+ * 
+ * @return Error code and state, if error occurs.
  */
-void screenDispose();
+errorret_t screenDispose();

src/dusk/display/shader/CMakeLists.txt

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

src/dusk/display/shader/shader.c

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "shader.h"
+#include "assert/assert.h"
+
+errorret_t shaderInit(shader_t *shader, const shaderdefinition_t *def) {
+  assertNotNull(shader, "Shader cannot be null");
+  errorChain(shaderInitPlatform(shader, def));
+  errorOk();
+}
+
+errorret_t shaderBind(shader_t *shader) {
+  assertNotNull(shader, "Shader cannot be null");
+  errorChain(shaderBindPlatform(shader));
+  errorOk();
+}
+
+errorret_t shaderSetMatrix(
+  shader_t *shader,
+  const char_t *name,
+  const mat4 matrix
+) {
+  assertNotNull(shader, "Shader cannot be null");
+  assertStrLenMin(name, 1, "Uniform name cannot be empty");
+  assertNotNull(matrix, "Matrix cannot be null");
+  errorChain(shaderSetMatrixPlatform(shader, name, matrix));
+  errorOk();
+}
+
+errorret_t shaderDispose(shader_t *shader) {
+  assertNotNull(shader, "Shader cannot be null");
+  errorChain(shaderDisposePlatform(shader));
+  errorOk();
+}

src/dusk/display/shader/shader.h

@@ -0,0 +1,80 @@
+/**
+ * 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/shader/shaderplatform.h"
+
+#ifndef shaderInitPlatform
+  #error "shaderInitPlatform must be defined to use shader.h"
+#endif
+#ifndef shaderBindPlatform
+  #error "shaderBindPlatform must be defined to use shader.h"
+#endif
+#ifndef shaderSetMatrixPlatform
+  #error "shaderSetMatrixPlatform must be defined to use shader.h"
+#endif
+#ifndef shaderDisposePlatform
+  #error "shaderDisposePlatform must be defined to use shader.h"
+#endif
+
+typedef shaderplatform_t shader_t;
+typedef shaderdefinitionplatform_t shaderdefinition_t;
+
+/**
+ * Initializes a shader. This is platform dependant.
+ * 
+ * @param shader Shader to initialize
+ * @param def Definition of the shader to initialize with.
+ * @return Error if failure, otherwise errorOk
+ */
+errorret_t shaderInit(shader_t *shader, const shaderdefinition_t *def);
+
+/**
+ * Binds a shader. This is platform dependant.
+ * 
+ * @param shader Shader to bind
+ * @return Error if failure, otherwise errorOk
+ */
+errorret_t shaderBind(shader_t *shader);
+
+/**
+ * Sets a matrix uniform in the shader. This is platform dependant.
+ * 
+ * @param shader Shader to set the matrix in
+ * @param name Name of the uniform to set
+ * @param matrix Matrix to set
+ * @return Error if failure, otherwise errorOk
+ */
+errorret_t shaderSetMatrix(
+  shader_t *shader,
+  const char_t *name,
+  const mat4 matrix
+);
+
+/**
+ * Sets a texture uniform in the shader. This is platform dependant.
+ * 
+ * @param shader Shader to set the texture in
+ * @param name Name of the uniform to set
+ * @param texture Texture to set
+ * @return Error if failure, otherwise errorOk
+ */
+errorret_t shaderSetTexture(
+  shader_t *shader,
+  const char_t *name,
+  texture_t *texture
+);
+
+/**
+ * Disposes of a shader. This is platform dependant.
+ * 
+ * @param shader Shader to dispose
+ * @return Error if failure, otherwise errorOk
+ */
+errorret_t shaderDispose(shader_t *shader);

src/dusk/display/shader/shaderunlit.h

@@ -0,0 +1,15 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "shader.h"
+
+#define SHADER_UNLIT_PROJECTION "u_Proj"
+#define SHADER_UNLIT_VIEW "u_View"
+#define SHADER_UNLIT_MODEL "u_Model"
+
+extern shaderdefinition_t SHADER_UNLIT_DEFINITION;

src/dusk/script/module/display/modulespritebatch.c

@@ -91,7 +91,7 @@ int moduleSpriteBatchPush(lua_State *L) {
   float_t maxX = (float_t)lua_tonumber(L, 4);
   float_t maxY = (float_t)lua_tonumber(L, 5);
   
-  spriteBatchPush(
+  errorret_t ret = spriteBatchPush(
     tex,
     minX,
     minY,
@@ -103,6 +103,14 @@ int moduleSpriteBatchPush(lua_State *L) {
     u1,
     v1
   );
+  if(ret.code != ERROR_OK) {
+    int err = luaL_error(L,
+      "Failed to push sprite to batch: %s",
+      ret.state->message
+    );
+    errorCatch(errorPrint(ret));
+    return err;
+  }
 
   return 0;
 }

src/duskgl/assert/assertgl.h

@@ -0,0 +1,15 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "assert/assert.h"
+#include "error/errorgl.h"
+
+#define assertNoGLError(message) \
+  assertTrue(errorGLCheck().code == ERROR_OK, message)
+
+// EOF

src/duskgl/display/CMakeLists.txt

@@ -14,3 +14,4 @@ add_subdirectory(camera)
 add_subdirectory(framebuffer)
 add_subdirectory(texture)
 add_subdirectory(mesh)
+add_subdirectory(shader)

src/duskgl/display/camera/cameragl.c

@@ -8,7 +8,7 @@
 #include "display/camera/camera.h"
 #include "display/framebuffer/framebuffer.h"
 #include "display/screen/screen.h"
-#include "assert/assert.h"
+#include "assert/assertgl.h"
 
 void cameraPushMatrixGL(camera_t *camera) {
   assertNotNull(camera, "Not a camera component");
@@ -117,16 +117,19 @@ void cameraPushMatrixGL(camera_t *camera) {
       assertUnreachable("Invalid camera view type");
   }
 
-  glPushMatrix();
+  // glPushMatrix();
-  glMatrixMode(GL_PROJECTION);
+  // glMatrixMode(GL_PROJECTION);
-  glLoadIdentity();
+  // glLoadIdentity();
-  glLoadMatrixf((const GLfloat*)projection);
+  // glLoadMatrixf((const GLfloat*)projection);
+  assertNoGLError("Failed to set projection matrix");
 
-  glMatrixMode(GL_MODELVIEW);
+  // glMatrixMode(GL_MODELVIEW);
-  glLoadIdentity();
+  // glLoadIdentity();
-  glLoadMatrixf((const GLfloat*)view);
+  // glLoadMatrixf((const GLfloat*)view);
+  assertNoGLError("Failed to set view matrix");
 }
 
 void cameraPopMatrixGL(void) {
-  glPopMatrix();
+  // glPopMatrix();
+  assertNoGLError("Failed to pop camera matrix");
 }

src/duskgl/display/displaygl.c

@@ -9,8 +9,8 @@
 
 errorret_t displayOpenGLInit(void) {
   glDisable(GL_CULL_FACE);
-  glDisable(GL_LIGHTING);// PSP defaults this on?
+  // glDisable(GL_LIGHTING);// PSP defaults this on?
-  glShadeModel(GL_SMOOTH); // Fixes color on PSP?
+  // glShadeModel(GL_SMOOTH); // Fixes color on PSP?
   errorChain(errorGLCheck());
 
   glEnable(GL_DEPTH_TEST);
@@ -24,9 +24,12 @@ errorret_t displayOpenGLInit(void) {
   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
   errorChain(errorGLCheck());
 
-  glEnableClientState(GL_COLOR_ARRAY);// To confirm: every frame on PSP?
+  // glEnableClientState(GL_COLOR_ARRAY);// To confirm: every frame on PSP?
-  glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+  // glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-  glEnableClientState(GL_VERTEX_ARRAY);
+  // glEnableClientState(GL_VERTEX_ARRAY);
-  errorChain(errorGLCheck());
+  // errorChain(errorGLCheck());
+
+  errorChain(shaderInit(&testShader, &SHADER_UNLIT_DEFINITION));
+
   errorOk();
 }

src/duskgl/display/displaygl.h

@@ -7,8 +7,13 @@
 
 #pragma once
 #include "error/errorgl.h"
+#include "display/shader/shaderunlit.h"
+
+static shadergl_t testShader;
 
 /**
  * Initializes the OpenGL specific contexts for rendering.
+ * 
+ * @return An errorret_t indicating success or failure of the initialization.
  */
 errorret_t displayOpenGLInit(void);

src/duskgl/display/framebuffer/framebuffergl.c

@@ -7,7 +7,7 @@
 
 #include "display/display.h"
 #include "display/framebuffer/framebuffer.h"
-#include "assert/assert.h"
+#include "assert/assertgl.h"
 #include "util/memory.h"
 
 errorret_t frameBufferGLInitBackBuffer(void) {
@@ -86,6 +86,7 @@ void frameBufferGLClear(const uint8_t flags, const color_t color) {
       color.b / 255.0f,
       color.a / 255.0f
     );
+    assertNoGLError("Failed to set clear color");
   }
 
   if(flags & FRAMEBUFFER_CLEAR_DEPTH) {
@@ -93,6 +94,7 @@ void frameBufferGLClear(const uint8_t flags, const color_t color) {
   }
 
   glClear(glFlags);
+  assertNoGLError("Failed to clear framebuffer");
 }
 
 #ifdef DUSK_DISPLAY_SIZE_DYNAMIC

src/duskgl/display/mesh/meshgl.c

@@ -6,7 +6,8 @@
  */
 
 #include "display/mesh/mesh.h"
-#include "assert/assert.h"
+#include "assert/assertgl.h"
+#include "error/errorgl.h"
 
 errorret_t meshInitGL(
   meshgl_t *mesh,
@@ -33,26 +34,27 @@ errorret_t meshDrawGL(
   // PSP style pointer legacy OpenGL
   const GLsizei stride = sizeof(meshvertex_t);
 
-  glColorPointer(
+  // glColorPointer(
-    sizeof(color4b_t),
+  //   sizeof(color4b_t),
-    GL_UNSIGNED_BYTE,
+  //   GL_UNSIGNED_BYTE,
-    stride,
+  //   stride,
-    (const GLvoid*)&mesh->vertices[offset].color
+  //   (const GLvoid*)&mesh->vertices[offset].color
-  );
+  // );
-  glTexCoordPointer(
+  // glTexCoordPointer(
-    MESH_VERTEX_UV_SIZE,
+  //   MESH_VERTEX_UV_SIZE,
-    GL_FLOAT,
+  //   GL_FLOAT,
-    stride,
+  //   stride,
-    (const GLvoid*)&mesh->vertices[offset].uv
+  //   (const GLvoid*)&mesh->vertices[offset].uv
-  );
+  // );
-  glVertexPointer(
+  // glVertexPointer(
-    MESH_VERTEX_POS_SIZE,
+  //   MESH_VERTEX_POS_SIZE,
-    GL_FLOAT,
+  //   GL_FLOAT,
-    stride,
+  //   stride,
-    (const GLvoid*)&mesh->vertices[offset].pos
+  //   (const GLvoid*)&mesh->vertices[offset].pos
-  );
+  // );
 
-  glDrawArrays(mesh->primitiveType, offset, count);
+  // glDrawArrays(mesh->primitiveType, offset, count);
+  // errorChain(errorGLCheck());
 
   errorOk();
 }

src/duskgl/display/shader/CMakeLists.txt

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

src/duskgl/display/shader/shadergl.c

@@ -0,0 +1,197 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "shadergl.h"
+#include "util/memory.h"
+#include "assert/assertgl.h"
+
+errorret_t shaderInitGL(shadergl_t *shader, const shaderdefinitiongl_t *def) {
+  assertNotNull(shader, "Shader cannot be null");
+  assertNotNull(def, "Shader definition cannot be null");
+
+  memoryZero(shader, sizeof(shadergl_t));
+
+  // Create vertex shader
+  shader->vertexShaderId = glCreateShader(GL_VERTEX_SHADER);
+  errorret_t err = errorGLCheck();
+  errorChain(err);
+
+  glShaderSource(shader->vertexShaderId, 1, &def->vert, NULL);
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteShader(shader->vertexShaderId);
+    errorChain(err);
+  }
+
+  glCompileShader(shader->vertexShaderId);
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteShader(shader->vertexShaderId);
+    errorChain(err);
+  }
+
+  GLint ok = 0;
+  glGetShaderiv(shader->vertexShaderId, GL_COMPILE_STATUS, &ok);
+  if(!ok) {
+    GLchar log[1024];
+    glGetShaderInfoLog(shader->vertexShaderId, sizeof(log), NULL, log);
+    glDeleteShader(shader->vertexShaderId);
+    errorThrow("Vertex shader compilation failed: %s", log);
+  }
+
+  // Create fragment shader
+  shader->fragmentShaderId = glCreateShader(GL_FRAGMENT_SHADER);
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteShader(shader->vertexShaderId);
+    errorChain(err);
+  }
+
+  glShaderSource(shader->fragmentShaderId, 1, &def->frag, NULL);
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteShader(shader->vertexShaderId);
+    glDeleteShader(shader->fragmentShaderId);
+    errorChain(err);
+  }
+
+  glCompileShader(shader->fragmentShaderId);
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteShader(shader->vertexShaderId);
+    glDeleteShader(shader->fragmentShaderId);
+    errorChain(err);
+  }
+
+  glGetShaderiv(shader->fragmentShaderId, GL_COMPILE_STATUS, &ok);
+  if(!ok) {
+    GLchar log[1024];
+    glGetShaderInfoLog(shader->fragmentShaderId, sizeof(log), NULL, log);
+    glDeleteShader(shader->vertexShaderId);
+    glDeleteShader(shader->fragmentShaderId);
+    errorThrow("Fragment shader compilation failed: %s", log);
+  }
+
+  // Create shader program
+  shader->shaderProgramId = glCreateProgram();
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteShader(shader->vertexShaderId);
+    glDeleteShader(shader->fragmentShaderId);
+    errorChain(err);
+  }
+
+  glAttachShader(shader->shaderProgramId, shader->vertexShaderId);
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteProgram(shader->shaderProgramId);
+    glDeleteShader(shader->vertexShaderId);
+    glDeleteShader(shader->fragmentShaderId);
+    errorChain(err);
+  }
+
+  glAttachShader(shader->shaderProgramId, shader->fragmentShaderId);
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteProgram(shader->shaderProgramId);
+    glDeleteShader(shader->vertexShaderId);
+    glDeleteShader(shader->fragmentShaderId);
+    errorChain(err);
+  }
+
+  glLinkProgram(shader->shaderProgramId);
+  err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    glDeleteProgram(shader->shaderProgramId);
+    glDeleteShader(shader->vertexShaderId);
+    glDeleteShader(shader->fragmentShaderId);
+    errorChain(err);
+  }
+
+  ok = 0;
+  glGetProgramiv(shader->shaderProgramId, GL_LINK_STATUS, &ok);
+  if(!ok) {
+    GLchar log[1024];
+    glGetProgramInfoLog(shader->shaderProgramId, sizeof(log), NULL, log);
+    glDeleteProgram(shader->shaderProgramId);
+    glDeleteShader(shader->vertexShaderId);
+    glDeleteShader(shader->fragmentShaderId);
+    errorThrow("Shader program linking failed: %s", log);
+  }
+
+  errorOk();
+}
+
+errorret_t shaderParamGetLocationGL(
+  shadergl_t *shader,
+  const char_t *name,
+  GLint *location
+) {
+  assertNotNull(shader, "Shader cannot be null");
+  assertStrLenMin(name, 1, "Uniform name cannot be empty");
+  assertNotNull(location, "Location cannot be null");
+
+  shadergl_t *shaderGL = (shadergl_t *)shader;
+  *location = glGetUniformLocation(shaderGL->shaderProgramId, name);
+  errorret_t err = errorGLCheck();
+  if(err.code != ERROR_OK) {
+    errorChain(err);
+  }
+  
+  errorOk();
+}
+
+errorret_t shaderSetMatrixGL(
+  shadergl_t *shader,
+  const char_t *name,
+  const mat4 mat
+) {
+  assertNotNull(shader, "Shader cannot be null");
+  assertNotNull(mat, "Matrix data cannot be null");
+  assertStrLenMin(name, 1, "Uniform name cannot be empty");
+
+  GLint location;
+  errorChain(shaderParamGetLocationGL(shader, name, &location));
+
+  glUniformMatrix4fv(location, 1, GL_FALSE, (const GLfloat *)mat);
+  errorChain(errorGLCheck());
+
+  errorOk();
+}
+
+
+errorret_t shaderBindGL(shadergl_t *shader) {
+  assertNotNull(shader, "Shader cannot be null");
+
+  glUseProgram(shader->shaderProgramId);
+  errorChain(errorGLCheck());
+
+  errorOk();
+}
+
+errorret_t shaderDisposeGL(shadergl_t *shader) {
+  assertNotNull(shader, "Shader cannot be null");
+
+  if(shader->shaderProgramId != 0) {
+    glDeleteProgram(shader->shaderProgramId);
+    errorChain(errorGLCheck());
+  }
+  
+  if(shader->vertexShaderId != 0) {
+    glDeleteShader(shader->vertexShaderId);
+    errorChain(errorGLCheck());
+  }
+
+  if(shader->fragmentShaderId != 0) {
+    glDeleteShader(shader->fragmentShaderId);
+    errorChain(errorGLCheck());
+  }
+
+  assertNoGLError("Failed disposing shader");
+  memoryZero(shader, sizeof(shadergl_t));
+  errorOk();
+}

src/duskgl/display/shader/shadergl.h

@@ -0,0 +1,72 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/errorgl.h"
+
+typedef struct {
+  GLuint shaderProgramId;
+  GLuint vertexShaderId;
+  GLuint fragmentShaderId;
+} shadergl_t;
+
+typedef struct {
+  const char_t *vert;
+  const char_t *frag;
+} shaderdefinitiongl_t;
+
+/**
+ * Initializes a shader.
+ * 
+ * @param shader The shader to initialize.
+ * @param def The definition of the shader to initialize with.
+ * @return An errorret_t indicating success or failure.
+ */
+errorret_t shaderInitGL(shadergl_t *shader, const shaderdefinitiongl_t *def);
+
+/**
+ * Binds a shader for use in rendering.
+ * 
+ * @param shader The shader to bind.
+ * @return An errorret_t indicating success or failure.
+ */
+errorret_t shaderBindGL(shadergl_t *shader);
+
+/**
+ * Retrieves the location of a shader uniform parameter.
+ * 
+ * @param shader The shader to query.
+ * @param name The name of the uniform parameter.
+ * @param location Output parameter to receive the location of the uniform.
+ * @return An errorret_t indicating success or failure.
+ */
+errorret_t shaderParamGetLocationGL(
+  shadergl_t *shader,
+  const char_t *name,
+  GLint *location
+);
+
+/**
+ * Sets a mat4 uniform parameter in the shader.
+ * 
+ * @param shader The shader to update.
+ * @param name The name of the uniform parameter.
+ * @param mat The 4x4 matrix data to set.
+ * @return An errorret_t indicating success or failure.
+ */
+errorret_t shaderSetMatrixGL(
+  shadergl_t *shader,
+  const char_t *name,
+  const mat4 matrix
+);
+
+/**
+ * Disposes of a shader, freeing any associated resources.
+ * 
+ * @param shader The shader to dispose.
+ */
+errorret_t shaderDisposeGL(shadergl_t *shader);

src/duskgl/display/shader/shaderplatform.h

@@ -0,0 +1,18 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "shadergl.h"
+
+typedef shadergl_t shaderplatform_t;
+typedef shaderdefinitiongl_t shaderdefinitionplatform_t;
+
+#define shaderInitPlatform shaderInitGL
+#define shaderBindPlatform shaderBindGL
+#define shaderSetMatrixPlatform shaderSetMatrixGL
+// #define shaderSetTexturePlatform shaderSetTextureGL
+#define shaderDisposePlatform shaderDisposeGL

src/duskgl/display/shader/shaderunlitgl.c

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "display/shader/shaderunlit.h"
+
+shaderdefinition_t SHADER_UNLIT_DEFINITION = {
+  .vert =
+    "#version 330 core\n"
+    "layout(location = 0) in vec3 aPos;\n"
+    "layout(location = 1) in vec2 aTexCoord;\n"
+    "uniform mat4 u_Proj;\n"
+    "uniform mat4 u_View;\n"
+    "uniform mat4 u_Model;\n"
+    "out vec2 v_TexCoord;\n"
+    "void main() {\n"
+    "  gl_Position = u_Proj * u_View * u_Model * vec4(aPos, 1.0);\n"
+    "  v_TexCoord = aTexCoord;\n"
+    "}\n",
+
+  .frag =
+    "#version 330 core\n"
+    "in vec2 v_TexCoord;\n"
+    "out vec4 FragColor;\n"
+    "uniform sampler2D u_Texture;\n"
+    "void main() {\n"
+    "  FragColor = texture(u_Texture, v_TexCoord);\n"
+    "}\n"
+};

src/dusksdl2/display/displaysdl2.c

@@ -21,6 +21,11 @@ errorret_t displaySDL2Init(void) {
 
   // Set OpenGL attributes (Needs to be done now or later?)
   SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+  // SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
+  // SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
+  
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
 
   // Create window with OpenGL flag.
   DISPLAY.window = SDL_CreateWindow(
@@ -44,7 +49,6 @@ errorret_t displaySDL2Init(void) {
   errorChain(errorGLCheck());
 
   SDL_GL_SetSwapInterval(1);
-  SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
   errorChain(errorGLCheck());
 
   errorChain(displayOpenGLInit());
@@ -82,6 +86,9 @@ errorret_t displaySDL2Update(void) {
   }
 
   SDL_GL_MakeCurrent(DISPLAY.window, DISPLAY.glContext);
+
+  // errorChain(shaderPaletteTextureBindGL(&testShader));
+  
   errorOk();
 }