Resolve SwapchainTexture format on acquisition.

Also simplify beginFrame

Author: jdolan

Examples/Hello.c

@@ -241,6 +241,7 @@ SDL_AppResult SDL_AppInit(void **appState, int argc, char *argv[]) {
   SDL_GetWindowSizeInPixels(app->window, &w, &h);
 
   const SDL_GPUTextureFormat colorFormat = $(app->renderDevice, getSwapchainTextureFormat);
+  
   app->framebuffer = $(app->renderDevice, createFramebuffer, &(GPU_FramebufferCreateInfo) {
     .size = MakeSize(w, h),
     .colorFormats = { colorFormat },

Examples/HelloCompute.c

@@ -195,6 +195,7 @@ SDL_AppResult SDL_AppInit(void **appState, int argc, char *argv[]) {
   SDL_GetWindowSizeInPixels(app->window, &w, &h);
 
   const SDL_GPUTextureFormat colorFormat = $(app->renderDevice, getSwapchainTextureFormat);
+  
   app->framebuffer = $(app->renderDevice, createFramebuffer, &(GPU_FramebufferCreateInfo) {
     .size = MakeSize(w, h),
     .colorFormats = { colorFormat },

Sources/ObjectivelyGPU/CommandBuffer.c

@@ -61,7 +61,12 @@ static bool acquireSwapchainTexture(const CommandBuffer *self, SwapchainTexture
                                                  self->device->window,
                                                  &swapchain->texture,
                                                  &w, &h);
-  swapchain->size = (SDL_Size) { (int) w, (int) h };
+
+  if (ok) {
+    swapchain->size = (SDL_Size) { (int) w, (int) h };
+    swapchain->format = SDL_GetGPUSwapchainTextureFormat(self->device->device, self->device->window);
+  }
+  
   return ok;
 }
 
@@ -266,7 +271,11 @@ static bool waitAndAcquireSwapchainTexture(const CommandBuffer *self, SwapchainT
                                                         self->device->window,
                                                         &swapchain->texture,
                                                         &w, &h);
-  swapchain->size = (SDL_Size) { (int) w, (int) h };
+  if (ok) {
+    swapchain->size = (SDL_Size) { (int) w, (int) h };
+    swapchain->format = SDL_GetGPUSwapchainTextureFormat(self->device->device, self->device->window);
+  }
+  
   return ok;
 }
 

Sources/ObjectivelyGPU/CommandBuffer.h

@@ -52,6 +52,11 @@ struct SwapchainTexture {
    */
   SDL_GPUTexture *texture;
 
+  /**
+   * @brief The swapchain texture format.
+   */
+  SDL_GPUTextureFormat format;
+
   /**
    * @brief The swapchain dimensions in pixels.
    */

Sources/ObjectivelyGPU/RenderDevice.c

@@ -98,25 +98,19 @@ static CommandBuffer *acquireCommandBuffer(const RenderDevice *self) {
 static CommandBuffer *beginFrame(RenderDevice *self) {
 
   GPU_Assert(self->framebuffer, "no framebuffer set; call setFramebuffer first");
-  GPU_Assert(!self->commandBuffer, "beginFrame called with a frame already in flight");
+  GPU_Assert(self->commandBuffer == NULL, "beginFrame called with a frame already in flight");
 
-  CommandBuffer *commands = $(self, acquireCommandBuffer);
+  self->commandBuffer = $(self, acquireCommandBuffer);
 
-  SwapchainTexture swapchain = { 0 };
-  $(commands, waitAndAcquireSwapchainTexture, &swapchain);
-
-  if (!swapchain.texture) {
-    $(commands, cancel);
-    release(commands);
-    return NULL;
+  const bool ok = $(self->commandBuffer, waitAndAcquireSwapchainTexture, &self->swapchain);
+  if (ok) {
+    $(self->framebuffer, resize, &self->swapchain.size);
+  } else {
+    $(self->commandBuffer, cancel);
+    self->commandBuffer = release(self->commandBuffer);
   }
 
-  $(self->framebuffer, resize, &swapchain.size);
-
-  self->commandBuffer = commands;
-  self->swapchain = swapchain;
-
-  return commands;
+  return self->commandBuffer;
 }
 
 /**
@@ -147,8 +141,8 @@ static void endFrame(RenderDevice *self) {
 
   $(self->commandBuffer, submit);
 
-  release(self->commandBuffer);
-  self->commandBuffer = NULL;
+  self->commandBuffer = release(self->commandBuffer);
+  
   self->swapchain = (SwapchainTexture) { 0 };
 }
 
@@ -366,8 +360,11 @@ static bool setAllowedFramesInFlight(const RenderDevice *self, Uint32 allowed) {
 static void setFramebuffer(RenderDevice *self, Framebuffer *framebuffer) {
 
   if (self->framebuffer != framebuffer) {
-    release(self->framebuffer);
-    self->framebuffer = framebuffer ? retain(framebuffer) : NULL;
+    self->framebuffer = release(self->framebuffer);
+    
+    if (framebuffer) {
+      self->framebuffer = retain(framebuffer);
+    }
   }
 }