Transfer usage restructuring and D3D11 async readback (#42)

Author: thatcosmonaut

include/SDL3/SDL_gpu.h

@@ -177,13 +177,11 @@ typedef enum SDL_GpuBufferUsageFlagBits
 
 typedef Uint32 SDL_GpuBufferUsageFlags;
 
-typedef enum SDL_GpuTransferBufferMapFlagBits
+typedef enum SDL_GpuTransferBufferUsage
 {
-    SDL_GPU_TRANSFER_MAP_READ = 0x00000001,
-    SDL_GPU_TRANSFER_MAP_WRITE = 0x00000002
-} SDL_GpuTransferBufferMapFlagBits;
-
-typedef Uint32 SDL_GpuTransferBufferMapFlags;
+    SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD,
+    SDL_GPU_TRANSFERBUFFERUSAGE_DOWNLOAD
+} SDL_GpuTransferBufferUsage;
 
 typedef enum SDL_GpuShaderStage
 {
@@ -336,12 +334,6 @@ typedef enum SDL_GpuBorderColor
     SDL_GPU_BORDERCOLOR_INT_OPAQUE_WHITE
 } SDL_GpuBorderColor;
 
-typedef enum SDL_GpuTransferUsage
-{
-    SDL_GPU_TRANSFERUSAGE_BUFFER,
-    SDL_GPU_TRANSFERUSAGE_TEXTURE
-} SDL_GpuTransferUsage;
-
 /*
  * VSYNC:
  *   Waits for vblank before presenting.
@@ -950,8 +942,7 @@ extern SDL_DECLSPEC SDL_GpuBuffer *SDLCALL SDL_GpuCreateBuffer(
  * Creates a transfer buffer to be used when uploading to or downloading from graphics resources.
  *
  * \param device a GPU Context
- * \param usage specifies whether the transfer buffer will transfer buffers or textures
- * \param mapFlags specify read-write options for the transfer buffer
+ * \param usage whether the transfer buffer will be used for uploads or downloads
  * \param sizeInBytes the size of the transfer buffer
  * \returns a transfer buffer on success, or NULL on failure
  *
@@ -965,8 +956,7 @@ extern SDL_DECLSPEC SDL_GpuBuffer *SDLCALL SDL_GpuCreateBuffer(
  */
 extern SDL_DECLSPEC SDL_GpuTransferBuffer *SDLCALL SDL_GpuCreateTransferBuffer(
     SDL_GpuDevice *device,
-    SDL_GpuTransferUsage usage,
-    SDL_GpuTransferBufferMapFlags mapFlags,
+    SDL_GpuTransferBufferUsage usage,
     Uint32 sizeInBytes);
 
 /* Debug Naming */

src/dynapi/SDL_dynapi_procs.h

@@ -1100,7 +1100,7 @@ SDL_DYNAPI_PROC(SDL_GpuSampler*,SDL_GpuCreateSampler,(SDL_GpuDevice *a, SDL_GpuS
 SDL_DYNAPI_PROC(SDL_GpuShader*,SDL_GpuCreateShader,(SDL_GpuDevice *a, SDL_GpuShaderCreateInfo *b),(a,b),return)
 SDL_DYNAPI_PROC(SDL_GpuTexture*,SDL_GpuCreateTexture,(SDL_GpuDevice *a, SDL_GpuTextureCreateInfo *b),(a,b),return)
 SDL_DYNAPI_PROC(SDL_GpuBuffer*,SDL_GpuCreateBuffer,(SDL_GpuDevice *a, SDL_GpuBufferUsageFlags b, Uint32 c),(a,b,c),return)
-SDL_DYNAPI_PROC(SDL_GpuTransferBuffer*,SDL_GpuCreateTransferBuffer,(SDL_GpuDevice *a, SDL_GpuTransferUsage b, SDL_GpuTransferBufferMapFlags c, Uint32 d),(a,b,c,d),return)
+SDL_DYNAPI_PROC(SDL_GpuTransferBuffer*,SDL_GpuCreateTransferBuffer,(SDL_GpuDevice *a, SDL_GpuTransferBufferUsage b, Uint32 c),(a,b,c),return)
 SDL_DYNAPI_PROC(void,SDL_GpuSetBufferName,(SDL_GpuDevice *a, SDL_GpuBuffer *b, const char *c),(a,b,c),)
 SDL_DYNAPI_PROC(void,SDL_GpuSetTextureName,(SDL_GpuDevice *a, SDL_GpuTexture *b, const char *c),(a,b,c),)
 SDL_DYNAPI_PROC(void,SDL_GpuSetStringMarker,(SDL_GpuCommandBuffer *a, const char *b),(a,b),)

src/gpu/SDL_gpu.c

@@ -444,15 +444,13 @@ SDL_GpuBuffer *SDL_GpuCreateBuffer(
 
 SDL_GpuTransferBuffer *SDL_GpuCreateTransferBuffer(
     SDL_GpuDevice *device,
-    SDL_GpuTransferUsage usage,
-    SDL_GpuTransferBufferMapFlags mapFlags,
+    SDL_GpuTransferBufferUsage usage,
     Uint32 sizeInBytes)
 {
     NULL_ASSERT(device)
     return device->CreateTransferBuffer(
         device->driverData,
         usage,
-        mapFlags,
         sizeInBytes);
 }
 

src/gpu/SDL_gpu_driver.h

@@ -231,8 +231,7 @@ struct SDL_GpuDevice
 
     SDL_GpuTransferBuffer *(*CreateTransferBuffer)(
         SDL_GpuRenderer *driverData,
-        SDL_GpuTransferUsage usage,
-        SDL_GpuTransferBufferMapFlags mapFlags,
+        SDL_GpuTransferBufferUsage usage,
         Uint32 sizeInBytes);
 
     /* Debug Naming */