Render textg

src/dusksdl2/display/renderbackbuffer.c

@@ -6,30 +6,89 @@
  */
 
 #include "renderbackbuffer.h"
+#include "render.h"
 
 #if RENDER_USE_FRAMEBUFFER
-SDL_Texture *RENDER_BACKBUFFER;
+  SDL_Texture *RENDER_BACKBUFFER;
 #else
 
 #endif
 
-void renderBackBufferInit(void) {
+errorret_t renderBackBufferInit(void) {
   #if RENDER_USE_FRAMEBUFFER
     RENDER_BACKBUFFER = SDL_CreateTexture(
       RENDER_RENDERER,
       SDL_PIXELFORMAT_RGBA8888,
       SDL_TEXTUREACCESS_TARGET,
-      RENDER_WINDOW_WIDTH_DEFAULT,
-      RENDER_WINDOW_HEIGHT_DEFAULT
+      RENDER_WIDTH,
+      RENDER_HEIGHT
     );
 
     if(!RENDER_BACKBUFFER) {
-      assertUnreachable("SDL_CreateTexture failed\n");
-      return;
+      errorThrow("SDL_CreateTexture failed: %s", SDL_GetError());
     }
+
+    // Make sure we unbind the back buffer after creation
+    SDL_SetRenderTarget(RENDER_RENDERER, NULL);
   #else
     // No back buffer needed for window rendering
   #endif
 
+  errorOk();
+}
+
+void renderBackBufferBind(void) {
+  #if RENDER_USE_FRAMEBUFFER
+    SDL_SetRenderTarget(RENDER_RENDERER, RENDER_BACKBUFFER);
+  #endif
   
+  // Fill background with cornflower blue.
+  SDL_SetRenderDrawColor(RENDER_RENDERER, 100, 149, 237, 255);
+  SDL_RenderClear(RENDER_RENDERER);
+}
+
+void renderBackBufferUnbind(void) {
+  #if RENDER_USE_FRAMEBUFFER
+    SDL_SetRenderTarget(RENDER_RENDERER, NULL);
+  #endif
+}
+
+void renderBackBufferDraw(void) {
+  #if RENDER_USE_FRAMEBUFFER
+    // Clear background black
+    SDL_SetRenderDrawColor(RENDER_RENDERER, 0, 0, 0, 255);
+    SDL_RenderClear(RENDER_RENDERER);
+
+    // Create a quad that is scaled to fit but maintain original aspect ratio
+    int32_t windowWidth, windowHeight;
+    SDL_GetWindowSize(RENDER_WINDOW, &windowWidth, &windowHeight);
+
+    int32_t renderWidth, renderHeight, renderX, renderY;
+    if(RENDER_WIDTH * windowHeight > RENDER_HEIGHT * windowWidth) {
+      renderWidth = windowWidth;
+      renderHeight = (RENDER_HEIGHT * windowWidth) / RENDER_WIDTH;
+      renderX = 0;
+      renderY = (windowHeight - renderHeight) / 2;
+    } else {
+      renderWidth = (RENDER_WIDTH * windowHeight) / RENDER_HEIGHT;
+      renderHeight = windowHeight;
+      renderX = (windowWidth - renderWidth) / 2;
+      renderY = 0;
+    }
+
+    // Draw the back buffer texture
+    SDL_Rect destRect = { renderX, renderY, renderWidth, renderHeight };
+    SDL_RenderCopy(RENDER_RENDERER, RENDER_BACKBUFFER, NULL, &destRect);
+  #else
+    // No back buffer to draw
+  #endif
+}
+
+errorret_t renderBackBufferDispose(void) {
+  #if RENDER_USE_FRAMEBUFFER
+    SDL_DestroyTexture(RENDER_BACKBUFFER);
+    RENDER_BACKBUFFER = NULL;
+  #endif
+
+  errorOk();
 }