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

@@ -29,6 +29,7 @@ target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
   DUSK_SDL2
   DUSK_OPENGL
   DUSK_LINUX
+  DUSK_OPENGL_LEGACY
   DUSK_DISPLAY_SIZE_DYNAMIC
   DUSK_DISPLAY_WIDTH_DEFAULT=640
   DUSK_DISPLAY_HEIGHT_DEFAULT=480

cmake/targets/psp.cmake

@@ -36,6 +36,7 @@ target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
   DUSK_PSP
   DUSK_INPUT_GAMEPAD
   DUSK_PLATFORM_ENDIAN_LITTLE
+  DUSK_OPENGL_LEGACY
   DUSK_DISPLAY_WIDTH=480
   DUSK_DISPLAY_HEIGHT=272
 )

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/camera/camera.c

@@ -45,13 +45,63 @@ void cameraInitOrthographic(camera_t *camera) {
   camera->_2d.zoom = 1.0f;
 }
 
-void cameraPushMatrix(camera_t *camera) {
-  assertNotNull(camera, "Invalid camera");
-  cameraPushMatrixPlatform(camera);
+void cameraGetProjectionMatrix(camera_t *camera, mat4 dest) {
+  assertNotNull(camera, "Not a camera component");
+  assertNotNull(dest, "Destination matrix must not be null");
+
+  if(
+    camera->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE ||
+    camera->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED
+  ) {
+    glm_mat4_identity(dest);
+    glm_perspective(
+      camera->perspective.fov,
+      SCREEN.aspect,
+      camera->nearClip,
+      camera->farClip,
+      dest
+    );
+
+    if(camera->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED) {
+      dest[1][1] *= -1.0f;
+    }
+  } else if(camera->projType == CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC) {
+    glm_mat4_identity(dest);
+    glm_ortho(
+      camera->orthographic.left,
+      camera->orthographic.right,
+      camera->orthographic.top,
+      camera->orthographic.bottom,
+      camera->nearClip,
+      camera->farClip,
+      dest
+    );
+  }
 }
 
-void cameraPopMatrix(void) {
-  #ifdef cameraPopMatrixPlatform
-    cameraPopMatrixPlatform();
-  #endif
+void cameraGetViewMatrix(camera_t *camera, mat4 dest) {
+  assertNotNull(camera, "Not a camera component");
+  assertNotNull(dest, "Destination matrix must not be null");
+
+  if(camera->viewType == CAMERA_VIEW_TYPE_MATRIX) {
+    glm_mat4_copy(camera->view, dest);
+  } else if(camera->viewType == CAMERA_VIEW_TYPE_LOOKAT) {
+    glm_mat4_identity(dest);
+    glm_lookat(
+      camera->lookat.position,
+      camera->lookat.target,
+      camera->lookat.up,
+      dest
+    );
+  } else if(camera->viewType == CAMERA_VIEW_TYPE_2D) {
+    glm_mat4_identity(dest);
+    glm_lookat(
+      (vec3){ camera->_2d.position[0], camera->_2d.position[1], 0.5f },
+      (vec3){ camera->_2d.position[0], camera->_2d.position[1], 0.0f },
+      (vec3){ 0.0f, 1.0f, 0.0f },
+      dest
+    );
+  } else if(camera->viewType == CAMERA_VIEW_TYPE_LOOKAT_PIXEL_PERFECT) {
+    assertUnreachable("LOOKAT_PIXEL_PERFECT view type is not implemented yet");
+  }
 }

src/dusk/display/camera/camera.h

@@ -86,13 +86,17 @@ void cameraInitPerspective(camera_t *camera);
 void cameraInitOrthographic(camera_t *camera);
 
 /**
- * Pushes the camera's view matrix onto the matrix stack.
+ * Gets the projection matrix for a camera.
  * 
- * @param id The ID of the camera entity to use.
+ * @param camera Camera to get the projection matrix for
+ * @param dest Matrix to store the projection matrix in
  */
-void cameraPushMatrix(camera_t *camera);
+void cameraGetProjectionMatrix(camera_t *camera, mat4 dest);
 
 /**
- * Pops the camera's view matrix off the matrix stack.
+ * Gets the view matrix for a camera.
+ * 
+ * @param camera Camera to get the view matrix for
+ * @param dest Matrix to store the view matrix in
  */
-void cameraPopMatrix(void);
+void cameraGetViewMatrix(camera_t *camera, mat4 dest);

src/dusk/display/display.c

@@ -17,6 +17,8 @@
 #include "util/memory.h"
 #include "util/string.h"
 #include "asset/asset.h"
+#include "display/shader/shaderunlit.h"
+#include "time/time.h"
 
 display_t DISPLAY = { 0 };
 
@@ -27,6 +29,7 @@ errorret_t displayInit(void) {
     errorChain(displayPlatformInit());
   #endif
 
+  errorChain(shaderInit(&SHADER_UNLIT, &SHADER_UNLIT_DEFINITION));
   errorChain(quadInit());
   errorChain(frameBufferInitBackBuffer());
   errorChain(spriteBatchInit());
@@ -46,16 +49,40 @@ 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());
+  errorChain(shaderBind(&SHADER_UNLIT));
+
+  camera_t camera;
+  cameraInitOrthographic(&camera);
+  camera.orthographic.left = 0.0f;
+  camera.orthographic.right = SCREEN.width;
+  camera.orthographic.top = SCREEN.height;
+  camera.orthographic.bottom = 0.0f;
+
+  mat4 proj, view, model;
+  cameraGetProjectionMatrix(&camera, proj);
+  cameraGetViewMatrix(&camera, view);
+  glm_mat4_identity(model);
+
+  errorChain(shaderSetMatrix(&SHADER_UNLIT, SHADER_UNLIT_PROJECTION, proj));
+  errorChain(shaderSetMatrix(&SHADER_UNLIT, SHADER_UNLIT_VIEW, view));
+  errorChain(shaderSetMatrix(&SHADER_UNLIT, SHADER_UNLIT_MODEL, model));
+
+  errorChain(spriteBatchPush(
+    NULL,
+    TIME.time * 2.0f, TIME.time * 3.0f, 100, 100, COLOR_WHITE, 0, 0, 1, 1
+  ));
+  errorChain(spriteBatchFlush());
+
+  // errorCatch(errorPrint(sceneRender()));
 
   // Render UI
-  uiRender();
+  // uiRender();
 
   // Finish up
   screenUnbind();
@@ -69,6 +96,7 @@ errorret_t displayUpdate(void) {
 }
 
 errorret_t displayDispose(void) {
+  errorChain(shaderDispose(&SHADER_UNLIT));
   errorChain(spriteBatchDispose());
   screenDispose();
   errorChain(textDispose());

src/dusk/display/mesh/mesh.c

@@ -25,6 +25,29 @@ errorret_t meshInit(
   errorOk();
 }
 
+errorret_t meshFlush(
+  mesh_t *mesh,
+  const int32_t vertexOffset,
+  const int32_t vertexCount
+) {
+  #ifdef meshFlushPlatform
+    assertNotNull(mesh, "Mesh cannot be NULL");
+    assertTrue(vertexOffset >= 0, "Vertex offset must be non-negative.");
+    assertTrue(vertexCount == -1 || vertexCount > 0, "Vertex count incorrect.");
+
+    int32_t vertCount = meshGetVertexCount(mesh);
+    assertTrue(vertexOffset < (vertCount - 1), "Need at least one vert to draw");
+
+    int32_t drawCount = vertexCount;
+    if(vertexCount == -1) {
+      drawCount = vertCount - vertexOffset;
+    }
+
+    errorChain(meshFlushPlatform(mesh, vertexOffset, vertexCount));
+  #endif
+  errorOk();
+}
+
 errorret_t meshDraw(
   const mesh_t *mesh,
   const int32_t vertexOffset,
@@ -32,7 +55,7 @@ errorret_t meshDraw(
 ) {
   assertNotNull(mesh, "Mesh cannot be NULL");
   assertTrue(vertexOffset >= 0, "Vertex offset must be non-negative");
-  assertTrue(vertexCount >= -1, "Vertex count must be -1 or non-negative");
+  assertTrue(vertexCount == -1 || vertexCount > 0, "Incorrect vert count");
 
   int32_t vertDrawCount = vertexCount;
   if(vertexCount == -1) {

src/dusk/display/mesh/mesh.h

@@ -40,6 +40,22 @@ errorret_t meshInit(
   const meshvertex_t *vertices
 );
 
+/**
+ * Instructs the mesh to flush the vertices to the GPU. This is surprisingly 
+ * only really necessary on modern devices, as we tend to let older devices
+ * read the vertices from the main memory directly.
+ * 
+ * @param mesh Mesh to flush the vertices for.
+ * @param vertexOffset Start vertex to flush.
+ * @param vertexCount Count of vertices to flush, set to -1 for all.
+ * @return Error state.
+ */
+errorret_t meshFlush(
+  mesh_t *mesh,
+  const int32_t vertexOffset,
+  const int32_t vertexCount
+);
+
 /**
  * Draws a mesh.
  * 

src/dusk/display/screen/screen.c

@@ -9,6 +9,7 @@
 #include "assert/assert.h"
 #include "util/memory.h"
 #include "display/mesh/quad.h"
+#include "display/shader/shaderunlit.h"
 
 screen_t SCREEN;
 
@@ -44,11 +45,11 @@ 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 +60,7 @@ 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 +80,21 @@ void screenBind() {
           curFbHeight = frameBufferGetHeight(&SCREEN.framebuffer);
           if(curFbWidth == SCREEN.width && curFbHeight == SCREEN.height) {
             // Correct size, nothing to do.
-            frameBufferBind(&SCREEN.framebuffer);
-            return;
+            errorChain(frameBufferBind(&SCREEN.framebuffer));
+            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 +112,10 @@ 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 +139,26 @@ void screenBind() {
             SCREEN.width = newFbWidth;
             SCREEN.height = newFbHeight;
             SCREEN.aspect = (float_t)SCREEN.width / (float_t)SCREEN.height;
-            frameBufferBind(&SCREEN.framebuffer);
-            return;
+            errorChain(frameBufferBind(&SCREEN.framebuffer));
+            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 +178,10 @@ 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 +190,21 @@ void screenBind() {
           curFbWidth = frameBufferGetWidth(&SCREEN.framebuffer);
           curFbHeight = frameBufferGetHeight(&SCREEN.framebuffer);
           if(curFbWidth == newFbWidth && curFbHeight == newFbHeight) {
-            frameBufferBind(&SCREEN.framebuffer);
-            return;
+            errorChain(frameBufferBind(&SCREEN.framebuffer));
+            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 +224,10 @@ 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 +236,21 @@ void screenBind() {
           curFbWidth = frameBufferGetWidth(&SCREEN.framebuffer);
           curFbHeight = frameBufferGetHeight(&SCREEN.framebuffer);
           if(curFbWidth == newFbWidth && curFbHeight == newFbHeight) {
-            frameBufferBind(&SCREEN.framebuffer);
-            return;
+            errorChain(frameBufferBind(&SCREEN.framebuffer));
+            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 +271,11 @@ void screenBind() {
       break;
     }
   }
+
+  errorOk();
 }
 
-void screenUnbind() {
+errorret_t screenUnbind() {
   switch(SCREEN.mode) {
     // Nothing to do here.
     case SCREEN_MODE_BACKBUFFER:
@@ -275,7 +286,9 @@ 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 +299,19 @@ 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 +322,7 @@ void screenRender() {
     ) {
       if(!SCREEN.framebufferReady) {
         // Nothing to do here.
-        return;
+        errorOk();
       }
 
       float_t bbWidth, bbHeight;
@@ -356,23 +371,34 @@ void screenRender() {
         FRAMEBUFFER_CLEAR_COLOR | FRAMEBUFFER_CLEAR_DEPTH,
         COLOR_BLACK
       );
-      cameraPushMatrix(&SCREEN.framebufferCamera);
-      textureBind(&SCREEN.framebuffer.texture);
-      meshDraw(&SCREEN.frameBufferMesh, 0, -1);
-      cameraPopMatrix();
 
-      return;
+      shaderBind(&SHADER_UNLIT);
+      mat4 proj, view, model;
+      cameraGetProjectionMatrix(&SCREEN.framebufferCamera, proj);
+      cameraGetViewMatrix(&SCREEN.framebufferCamera, view);
+      glm_mat4_identity(model);
+      shaderSetMatrix(&SHADER_UNLIT, SHADER_UNLIT_PROJECTION, proj);
+      shaderSetMatrix(&SHADER_UNLIT, SHADER_UNLIT_VIEW, view);
+      shaderSetMatrix(&SHADER_UNLIT, SHADER_UNLIT_MODEL, model);
+
+      // errorChain(textureBind(&SCREEN.framebuffer.texture));
+      errorChain(meshDraw(&SCREEN.frameBufferMesh, 0, -1));
+
+      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,
+  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,
+  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 +1,16 @@
+/**
+ * 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;
+static shader_t SHADER_UNLIT;

src/dusk/display/spritebatch/spritebatch.c

@@ -19,7 +19,7 @@ errorret_t spriteBatchInit() {
     &SPRITEBATCH.mesh,
     QUAD_PRIMITIVE_TYPE,
     SPRITEBATCH_VERTEX_COUNT,
-    &SPRITEBATCH_VERTICES[0]
+    SPRITEBATCH_VERTICES
   ));
   errorOk();
 }
@@ -83,10 +83,10 @@ errorret_t spriteBatchFlush() {
     errorOk();
   }
 
+  size_t vertexCount = QUAD_VERTEX_COUNT * SPRITEBATCH.spriteCount;
+  errorChain(meshFlush(&SPRITEBATCH.mesh, 0, vertexCount));
   errorChain(textureBind(SPRITEBATCH.currentTexture));
-  errorChain(meshDraw(
-    &SPRITEBATCH.mesh, 0, QUAD_VERTEX_COUNT * SPRITEBATCH.spriteCount
-  ));
+  errorChain(meshDraw(&SPRITEBATCH.mesh, 0, vertexCount));
   spriteBatchClear();
   errorOk();
 }

src/dusk/display/spritebatch/spritebatch.h

@@ -9,7 +9,7 @@
 #include "display/mesh/quad.h"
 #include "display/texture/texture.h"
 
-#define SPRITEBATCH_SPRITES_MAX 16
+#define SPRITEBATCH_SPRITES_MAX 1
 #define SPRITEBATCH_VERTEX_COUNT (SPRITEBATCH_SPRITES_MAX * QUAD_VERTEX_COUNT) 
 
 

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

@@ -69,8 +69,6 @@ void moduleCamera(scriptcontext_t *context) {
 
   // Methods
   lua_register(context->luaState, "cameraCreate", moduleCameraCreate);
-  lua_register(context->luaState, "cameraPushMatrix", moduleCameraPushMatrix);
-  lua_register(context->luaState, "cameraPopMatrix", moduleCameraPopMatrix);
 }
 
 int moduleCameraCreate(lua_State *L) {
@@ -118,25 +116,6 @@ int moduleCameraCreate(lua_State *L) {
   return 1;
 }
 
-int moduleCameraPushMatrix(lua_State *L) {
-  assertNotNull(L, "Lua state cannot be NULL.");
-  assertTrue(lua_gettop(L) >= 1, "cameraPushMatrix requires 1 arg.");
-  assertTrue(lua_isuserdata(L, 1), "cameraPushMatrix arg must be userdata.");
-
-  // Camera should be provided (pointer to camera_t).
-  camera_t *cam = (camera_t *)luaL_checkudata(L, 1, "camera_mt");
-  assertNotNull(cam, "Camera pointer cannot be NULL.");
-
-  cameraPushMatrix(cam);
-  return 0;
-}
-
-int moduleCameraPopMatrix(lua_State *L) {
-  assertNotNull(L, "Lua state cannot be NULL.");
-  cameraPopMatrix();
-  return 0;
-}
-
   int moduleCameraIndex(lua_State *l) {
   assertNotNull(l, "Lua state cannot be NULL.");
 

src/dusk/script/module/display/modulecamera.h

@@ -23,22 +23,6 @@ void moduleCamera(scriptcontext_t *context);
  */
 int moduleCameraCreate(lua_State *L);
 
-/**
- * Script binding for pushing the camera matrix onto the matrix stack.
- * 
- * @param L The Lua state.
- * @return Number of return values on the Lua stack.
- */
-int moduleCameraPushMatrix(lua_State *L);
-
-/**
- * Script binding for popping the camera matrix from the matrix stack.
- * 
- * @param L The Lua state.
- * @return Number of return values on the Lua stack.
- */
-int moduleCameraPopMatrix(lua_State *L);
-
 /**
  * Getter for camera structure fields.
  * 

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/dusk/ui/ui.c

@@ -30,11 +30,11 @@ void uiRender(void) {
   UI.camera.orthographic.right = SCREEN.width;
   UI.camera.orthographic.top = SCREEN.height;
 
-  cameraPushMatrix(&UI.camera);
+  // cameraPushMatrix(&UI.camera);
   spriteBatchClear();
 
   spriteBatchFlush();
-  cameraPopMatrix();
+  // cameraPopMatrix();
 }
 
 void uiDispose(void) {

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();
-  glMatrixMode(GL_PROJECTION);
-  glLoadIdentity();
-  glLoadMatrixf((const GLfloat*)projection);
+  // glPushMatrix();
+  // glMatrixMode(GL_PROJECTION);
+  // glLoadIdentity();
+  // glLoadMatrixf((const GLfloat*)projection);
+  assertNoGLError("Failed to set projection matrix");
 
-  glMatrixMode(GL_MODELVIEW);
-  glLoadIdentity();
-  glLoadMatrixf((const GLfloat*)view);
+  // glMatrixMode(GL_MODELVIEW);
+  // glLoadIdentity();
+  // 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?
-  glShadeModel(GL_SMOOTH); // Fixes color on PSP?
+  // glDisable(GL_LIGHTING);// PSP defaults this on?
+  // glShadeModel(GL_SMOOTH); // Fixes color on PSP?
   errorChain(errorGLCheck());
 
   glEnable(GL_DEPTH_TEST);
@@ -24,9 +24,5 @@ errorret_t displayOpenGLInit(void) {
   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
   errorChain(errorGLCheck());
 
-  glEnableClientState(GL_COLOR_ARRAY);// To confirm: every frame on PSP?
-  glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-  glEnableClientState(GL_VERTEX_ARRAY);
-  errorChain(errorGLCheck());
   errorOk();
 }

src/duskgl/display/displaygl.h

@@ -10,5 +10,7 @@
 
 /**
  * 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 +6,9 @@
  */
 
 #include "display/mesh/mesh.h"
-#include "assert/assert.h"
+#include "assert/assertgl.h"
+#include "error/errorgl.h"
+#include "display/shader/shadergl.h"
 
 errorret_t meshInitGL(
   meshgl_t *mesh,
@@ -22,6 +24,99 @@ errorret_t meshInitGL(
   mesh->vertexCount = vertexCount;
   mesh->vertices = vertices;
 
+  #ifdef DUSK_OPENGL_LEGACY
+    // Nothing needed.
+    glEnableClientState(GL_COLOR_ARRAY);
+    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+    glEnableClientState(GL_VERTEX_ARRAY);
+    errorChain(errorGLCheck());
+  #else
+    // Generate Vertex Buffer Object
+    glGenBuffers(1, &mesh->vboId);
+    errorChain(errorGLCheck());
+    glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId);
+    errorChain(errorGLCheck());
+    glBufferData(
+      GL_ARRAY_BUFFER,
+      vertexCount * sizeof(meshvertex_t),
+      vertices,
+      GL_DYNAMIC_DRAW
+    );
+    errorChain(errorGLCheck());
+
+    // Generate Vertex Array Object
+    glGenVertexArrays(1, &mesh->vaoId);
+    errorChain(errorGLCheck());
+    glBindVertexArray(mesh->vaoId);
+    errorChain(errorGLCheck());
+    glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId);
+    errorChain(errorGLCheck());
+
+    // Set up vertex attribute pointers
+    glVertexAttribPointer(
+      0,
+      MESH_VERTEX_POS_SIZE,
+      GL_FLOAT,
+      GL_FALSE,
+      sizeof(meshvertex_t),
+      (const GLvoid*)offsetof(meshvertex_t, pos)
+    );
+    errorChain(errorGLCheck());
+    glEnableVertexAttribArray(0);
+    errorChain(errorGLCheck());
+
+    glVertexAttribPointer(
+      1,
+      MESH_VERTEX_UV_SIZE,
+      GL_FLOAT,
+      GL_FALSE,
+      sizeof(meshvertex_t),
+      (const GLvoid*)offsetof(meshvertex_t, uv)
+    );
+    errorChain(errorGLCheck());
+    glEnableVertexAttribArray(1);
+    errorChain(errorGLCheck());
+
+    glVertexAttribPointer(
+      2,
+      sizeof(color_t) / sizeof(GLubyte),
+      GL_UNSIGNED_BYTE,
+      GL_TRUE,
+      sizeof(meshvertex_t),
+      (const GLvoid*)offsetof(meshvertex_t, color)
+    );
+    errorChain(errorGLCheck());
+    glEnableVertexAttribArray(2);
+    errorChain(errorGLCheck());
+
+    // Unbind VAO and VBO to prevent accidental modification
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    errorChain(errorGLCheck());
+    glBindVertexArray(0);
+    errorChain(errorGLCheck());
+  #endif
+
+  errorOk();
+}
+
+errorret_t meshFlushGL(
+  meshgl_t *mesh,
+  const int32_t vertOffset,
+  const int32_t vertCount
+) {
+  #ifdef DUSK_OPENGL_LEGACY
+    // Nothing doing, we use the glClientState stuff.
+  #else
+    glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId);
+    errorChain(errorGLCheck());
+    glBufferData(
+      GL_ARRAY_BUFFER,
+      vertCount * sizeof(meshvertex_t),
+      &mesh->vertices[vertOffset],
+      GL_DYNAMIC_DRAW
+    );
+    errorChain(errorGLCheck());
+  #endif
   errorOk();
 }
 
@@ -30,7 +125,8 @@ errorret_t meshDrawGL(
   const int32_t offset,
   const int32_t count
 ) {
-  // PSP style pointer legacy OpenGL
+  #ifdef DUSK_OPENGL_LEGACY
+    // Legacy pointer style rendering
     const GLsizei stride = sizeof(meshvertex_t);
 
     glColorPointer(
@@ -52,7 +148,22 @@ errorret_t meshDrawGL(
       (const GLvoid*)&mesh->vertices[offset].pos
     );
 
+    // Shader may have model matrix here
+    #ifdef DUSK_OPENGL_LEGACY
+      errorChain(shaderLegacyMatrixUpdate());
+    #endif
+    
     glDrawArrays(mesh->primitiveType, offset, count);
+    errorChain(errorGLCheck());
+  #else
+    // Modern VAO/VBO rendering
+    glBindVertexArray(mesh->vaoId);
+    errorChain(errorGLCheck());
+    glDrawArrays(mesh->primitiveType, offset, count);
+    errorChain(errorGLCheck());
+    glBindVertexArray(0);
+    errorChain(errorGLCheck());
+  #endif
 
   errorOk();
 }
@@ -62,6 +173,13 @@ int32_t meshGetVertexCountGL(const meshgl_t *mesh) {
 }
 
 errorret_t meshDisposeGL(meshgl_t *mesh) {
+  #ifdef DUSK_OPENGL_LEGACY
     // No dynamic resources to free for this mesh implementation
+  #else
+    glDeleteBuffers(1, &mesh->vboId);
+    errorChain(errorGLCheck());
+    glDeleteVertexArrays(1, &mesh->vaoId);
+    errorChain(errorGLCheck());
+  #endif
   errorOk();
 }

src/duskgl/display/mesh/meshgl.h

@@ -16,9 +16,16 @@ typedef enum {
 } meshprimitivetypegl_t;
 
 typedef struct {
-  const meshvertex_t *vertices;
   int32_t vertexCount;
   meshprimitivetypegl_t primitiveType;
+  const meshvertex_t *vertices;
+  
+  #ifdef DUSK_OPENGL_LEGACY
+    // Nothing needed
+  #else
+    GLuint vaoId;
+    GLuint vboId;
+  #endif
 } meshgl_t;
 
 /**
@@ -37,6 +44,20 @@ errorret_t meshInitGL(
   const meshvertex_t *vertices
 );
 
+/**
+ * Flushes the vertices (stored in memory) to the GPU.
+ * 
+ * @param mesh Mesh to flush vertices for.
+ * @param vertOffset First vertice index to flush.
+ * @param vertCount Count of vertices to flush.
+ * @return Error state.
+ */
+errorret_t meshFlushGL(
+  meshgl_t *mesh,
+  const int32_t vertOffset,
+  const int32_t vertCount
+);
+
 /**
  * Draws a mesh using OpenGL.
  * 

src/duskgl/display/mesh/meshplatform.h

@@ -12,6 +12,7 @@ typedef meshprimitivetypegl_t meshprimitivetypeplatform_t;
 typedef meshgl_t meshplatform_t;
 
 #define meshInitPlatform meshInitGL
+#define meshFlushPlatform meshFlushGL
 #define meshDrawPlatform meshDrawGL
 #define meshGetVertexCountPlatform meshGetVertexCountGL
 #define meshDisposePlatform meshDisposeGL

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 +1,282 @@
+/**
+ * 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 "util/string.h"
+#include "assert/assertgl.h"
+#include "display/shader/shaderunlit.h"
+
+#ifdef DUSK_OPENGL_LEGACY
+  shaderlegacygl_t SHADER_LEGACY = { 0 };
+#endif
+
+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));
+
+  #ifdef DUSK_OPENGL_LEGACY
+    glm_mat4_identity(shader->view);
+    glm_mat4_identity(shader->proj);
+    glm_mat4_identity(shader->model);
+
+    SHADER_LEGACY.boundShader = NULL;
+    errorOk();
+  #else
+    // 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);
+    }
+  #endif
+
+  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");
+
+  #ifdef DUSK_OPENGL_LEGACY
+    assertUnreachable("Cannot get uniform locations on legacy opengl.");
+  #else
+    shadergl_t *shaderGL = (shadergl_t *)shader;
+    *location = glGetUniformLocation(shaderGL->shaderProgramId, name);
+    errorret_t err = errorGLCheck();
+    if(err.code != ERROR_OK) {
+      errorChain(err);
+    }
+  #endif
+  
+  errorOk();
+}
+
+errorret_t shaderSetMatrixGL(
+  shadergl_t *shader,
+  const char_t *name,
+  mat4 mat
+) {
+  assertNotNull(shader, "Shader cannot be null");
+  assertNotNull(mat, "Matrix data cannot be null");
+  assertStrLenMin(name, 1, "Uniform name cannot be empty");
+
+  #ifdef DUSK_OPENGL_LEGACY
+    assertTrue(
+      SHADER_LEGACY.boundShader == shader,
+      "Shader must be bound to set legacy matrices."
+    );
+    if(stringCompare(name, SHADER_UNLIT_PROJECTION) == 0) {
+      SHADER_LEGACY.dirty |= SHADER_LEGACY_DIRTY_PROJ;
+      glm_mat4_copy(mat, shader->proj);
+
+    } else if(stringCompare(name, SHADER_UNLIT_VIEW) == 0) {
+      SHADER_LEGACY.dirty |= SHADER_LEGACY_DIRTY_VIEW;
+      glm_mat4_copy(mat, shader->view);
+
+    } else if(stringCompare(name, SHADER_UNLIT_MODEL) == 0) {
+      SHADER_LEGACY.dirty |= SHADER_LEGACY_DIRTY_MODEL;
+      glm_mat4_copy(mat, shader->model);
+      
+    } else {
+      assertUnreachable("Cannot use a custom matrix on legacy opengl.");
+    }
+  #else
+    GLint location;
+    errorChain(shaderParamGetLocationGL(shader, name, &location));
+
+    glUniformMatrix4fv(location, 1, GL_FALSE, (const GLfloat *)mat);
+    errorChain(errorGLCheck());
+  #endif
+
+  errorOk();
+}
+
+
+errorret_t shaderBindGL(shadergl_t *shader) {
+  #ifdef DUSK_OPENGL_LEGACY
+    assertNotNull(shader, "Cannot bind a null shader.");
+    SHADER_LEGACY.boundShader = shader;
+    SHADER_LEGACY.dirty = (
+      SHADER_LEGACY_DIRTY_MODEL |
+      SHADER_LEGACY_DIRTY_PROJ |
+      SHADER_LEGACY_DIRTY_VIEW
+    );
+  #else
+    assertNotNull(shader, "Shader cannot be null");
+    glUseProgram(shader->shaderProgramId);
+    errorChain(errorGLCheck());
+  #endif
+
+  errorOk();
+}
+
+errorret_t shaderDisposeGL(shadergl_t *shader) {
+  assertNotNull(shader, "Shader cannot be null");
+
+  #ifdef DUSK_OPENGL_LEGACY
+    SHADER_LEGACY.boundShader = NULL;
+  #else
+    if(shader->shaderProgramId != 0) {
+      glDeleteProgram(shader->shaderProgramId);
+    }
+    
+    if(shader->vertexShaderId != 0) {
+      glDeleteShader(shader->vertexShaderId);
+    }
+
+    if(shader->fragmentShaderId != 0) {
+      glDeleteShader(shader->fragmentShaderId);
+    }
+
+    assertNoGLError("Failed disposing shader");
+  #endif
+
+  memoryZero(shader, sizeof(shadergl_t));
+  errorOk();
+}
+
+#ifdef DUSK_OPENGL_LEGACY
+  errorret_t shaderLegacyMatrixUpdate() {
+    assertNotNull(SHADER_LEGACY.boundShader, "No shader is currently bound.");
+
+    if((SHADER_LEGACY.dirty & SHADER_LEGACY_DIRTY_PROJ) != 0) {
+      glMatrixMode(GL_PROJECTION);
+      errorChain(errorGLCheck());
+      glLoadIdentity();
+      errorChain(errorGLCheck());
+      glMultMatrixf((const GLfloat *)SHADER_LEGACY.boundShader->proj);
+      errorChain(errorGLCheck());
+    }
+
+    if((SHADER_LEGACY.dirty & SHADER_LEGACY_DIRTY_VIEW) != 0) {
+      glMatrixMode(GL_MODELVIEW);
+      errorChain(errorGLCheck());
+      glLoadIdentity();
+      errorChain(errorGLCheck());
+      glMultMatrixf((const GLfloat *)SHADER_LEGACY.boundShader->view);
+      errorChain(errorGLCheck());
+    }
+
+    if((SHADER_LEGACY.dirty & SHADER_LEGACY_DIRTY_MODEL) != 0) {
+      glMatrixMode(GL_MODELVIEW);
+      errorChain(errorGLCheck());
+      glMultMatrixf((const GLfloat *)SHADER_LEGACY.boundShader->model);
+      errorChain(errorGLCheck());
+    }
+    
+    SHADER_LEGACY.dirty = 0;
+    errorOk();
+  }
+#endif

src/duskgl/display/shader/shadergl.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/errorgl.h"
+
+typedef struct {
+  #ifdef DUSK_OPENGL_LEGACY
+    void *nothing;
+  #else
+    GLuint shaderProgramId;
+    GLuint vertexShaderId;
+    GLuint fragmentShaderId;
+  #endif
+
+  #if DUSK_OPENGL_LEGACY
+    mat4 view;
+    mat4 proj;
+    mat4 model;
+  #endif
+} shadergl_t;
+
+typedef struct {
+  #ifdef DUSK_OPENGL_LEGACY
+    void *nothing;
+  #else
+    const char_t *vert;
+    const char_t *frag;
+  #endif
+} shaderdefinitiongl_t;
+
+#if DUSK_OPENGL_LEGACY
+  typedef struct {
+    shadergl_t *boundShader;
+    uint_fast8_t dirty;
+  } shaderlegacygl_t;
+
+  extern shaderlegacygl_t SHADER_LEGACY;
+  
+  #define SHADER_LEGACY_DIRTY_PROJ (1 << 0)
+  #define SHADER_LEGACY_DIRTY_VIEW (1 << 1)
+  #define SHADER_LEGACY_DIRTY_MODEL (1 << 2)
+#endif
+
+/**
+ * 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,
+  mat4 matrix
+);
+
+/**
+ * Disposes of a shader, freeing any associated resources.
+ * 
+ * @param shader The shader to dispose.
+ */
+errorret_t shaderDisposeGL(shadergl_t *shader);
+
+#ifdef DUSK_OPENGL_LEGACY
+  /**
+   * During mesh rendering, this is requesting the legacy system to push all
+   * shaders necessary to render the currently bound shader's matrices.
+   * 
+   * @return Any error state.
+   */
+  errorret_t shaderLegacyMatrixUpdate();
+#endif

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 +1,31 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "display/shader/shaderunlit.h"
+
+#ifdef DUSK_OPENGL_LEGACY
+  shaderdefinition_t SHADER_UNLIT_DEFINITION = { 0 };
+#else
+  shaderdefinition_t SHADER_UNLIT_DEFINITION = {
+    .vert =
+      "#version 330 core\n"
+      "layout(location = 0) in vec3 aPos;\n"
+      "uniform mat4 u_Proj;\n"
+      "uniform mat4 u_View;\n"
+      "uniform mat4 u_Model;\n"
+      "void main() {\n"
+      "  gl_Position = u_Proj * u_View * u_Model * vec4(aPos, 1.0);\n"
+      "}\n",
+
+    .frag =
+      "#version 330 core\n"
+      "out vec4 FragColor;\n"
+      "void main() {\n"
+      "  FragColor = vec4(1.0, 0.0, 0.0, 1.0);\n" 
+      "}\n"
+  };
+#endif

src/dusksdl2/display/displaysdl2.c

@@ -21,6 +21,16 @@ 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);
+
+  #ifdef DUSK_OPENGL_LEGACY
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_COMPATIBILITY);
+  #else
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
+  #endif
 
   // Create window with OpenGL flag.
   DISPLAY.window = SDL_CreateWindow(
@@ -44,7 +54,6 @@ errorret_t displaySDL2Init(void) {
   errorChain(errorGLCheck());
 
   SDL_GL_SetSwapInterval(1);
-  SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
   errorChain(errorGLCheck());
 
   errorChain(displayOpenGLInit());
@@ -82,6 +91,9 @@ errorret_t displaySDL2Update(void) {
   }
 
   SDL_GL_MakeCurrent(DISPLAY.window, DISPLAY.glContext);
+
+  // errorChain(shaderPaletteTextureBindGL(&testShader));
+  
   errorOk();
 }