Add backbuffer

src/display/framebuffer/framebuffer.c

@@ -0,0 +1,141 @@
+/**
+ * Copyright (c) 2025 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "framebuffer.h"
+#include "assert/assert.h"
+#include "util/memory.h"
+
+framebuffer_t FRAMEBUFFER_BACKBUFFER = {0};
+const framebuffer_t *FRAMEBUFFER_BOUND = &FRAMEBUFFER_BACKBUFFER;
+
+void frameBufferInitBackbuffer() {
+  memoryZero(&FRAMEBUFFER_BACKBUFFER, sizeof(framebuffer_t));
+
+  FRAMEBUFFER_BACKBUFFER.id = -1;
+  FRAMEBUFFER_BOUND = &FRAMEBUFFER_BACKBUFFER;
+}
+
+int32_t frameBufferGetWidth(const framebuffer_t *framebuffer) {
+  #if DUSK_DISPLAY_SDL2
+    if(framebuffer == &FRAMEBUFFER_BACKBUFFER) {
+      int32_t windowWidth, windowHeight;
+      SDL_GetWindowSize(DISPLAY.window, &windowWidth, &windowHeight);
+      return windowWidth;
+    }
+
+    assertUnreachable("Framebuffer width not implemented");
+    return 0;
+  #endif
+}
+
+int32_t frameBufferGetHeight(const framebuffer_t *framebuffer) {
+  #if DUSK_DISPLAY_SDL2
+    if(framebuffer == &FRAMEBUFFER_BACKBUFFER) {
+      int32_t windowWidth, windowHeight;
+      SDL_GetWindowSize(DISPLAY.window, &windowWidth, &windowHeight);
+      return windowHeight;
+    }
+
+    assertUnreachable("Framebuffer height not implemented");
+    return 0;
+  #endif
+}
+
+void frameBufferBind(const framebuffer_t *framebuffer) {
+  if(framebuffer == NULL) {
+    #if DUSK_DISPLAY_SDL2
+      frameBufferBind(&FRAMEBUFFER_BACKBUFFER);
+    #endif
+
+    FRAMEBUFFER_BOUND = &FRAMEBUFFER_BACKBUFFER;
+    return;
+  }
+
+  // Bind the framebuffer for rendering
+  #if DUSK_DISPLAY_SDL2
+    if(framebuffer == &FRAMEBUFFER_BACKBUFFER) {
+
+      glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+      int32_t windowWidth, windowHeight;
+      SDL_GetWindowSize(DISPLAY.window, &windowWidth, &windowHeight);
+    } else {
+      glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer->id);
+    }
+    glViewport(
+      0, 0,
+      frameBufferGetWidth(framebuffer), frameBufferGetHeight(framebuffer)
+    );
+  #endif
+
+  FRAMEBUFFER_BOUND = framebuffer;
+}
+
+/**
+ * Disposes of the framebuffer using EXT methods.
+ * 
+ * @param framebuffer The framebuffer to dispose of.
+ */
+void frameBufferDispose(framebuffer_t *framebuffer) {
+  assertNotNull(framebuffer, "Framebuffer cannot be NULL");
+
+  #if DUSK_DISPLAY_SDL2
+    if(framebuffer == &FRAMEBUFFER_BACKBUFFER) {
+      assertUnreachable("Cannot dispose of backbuffer");
+    }
+
+    glDeleteFramebuffersEXT(1, &framebuffer->id);
+  #endif
+}
+
+// #if RENDER_USE_FRAMEBUFFER
+//   void frameBufferInit(
+//     framebuffer_t *framebuffer,
+//     const uint32_t width,
+//     const uint32_t height
+//   ) {
+//     assertNotNull(framebuffer, "Framebuffer cannot be NULL");
+//     assertTrue(width > 0 && height > 0, "Width & height must be greater than 0");
+
+//     memoryZero(framebuffer, sizeof(framebuffer_t));
+//     textureInit(&framebuffer->texture, width, height, GL_RGBA, NULL);
+
+//     // Generate the framebuffer object using EXT
+//     glGenFramebuffersEXT(1, &framebuffer->id);
+//     glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer->id);
+
+//     // Attach the texture to the framebuffer
+//     glFramebufferTexture2DEXT(
+//       GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
+//       GL_TEXTURE_2D, framebuffer->texture.id, 0
+//     );
+
+//     // Check if the framebuffer is complete
+//     if(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT) != GL_FRAMEBUFFER_COMPLETE_EXT) {
+//       assertUnreachable("Framebuffer is not complete");
+//     }
+
+//     // Unbind the framebuffer
+//     glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+//   }
+
+//   void frameBufferBind(const framebuffer_t *framebuffer) {
+//     if(framebuffer == NULL) {
+//       glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+//       return;
+//     }
+
+//     // Bind the framebuffer for rendering
+//     glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer->id);
+//   }
+
+//   void frameBufferDispose(framebuffer_t *framebuffer) {
+//     assertNotNull(framebuffer, "Framebuffer cannot be NULL");
+
+//     glDeleteFramebuffersEXT(1, &framebuffer->id);
+//     textureDispose(&framebuffer->texture);
+//   }
+// #endif