Rename stepRate to instanceStepRate (#230)

Also actually implements the step rate on the Metal backend.
thatcosmonaut · Aug 28, 2024 · 29b775e · 29b775e
1 parent 4380e53
commit 29b775e
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Showing 6 changed files with 6 additions and 5 deletions.
diff --git a/include/SDL3/SDL_gpu.h b/include/SDL3/SDL_gpu.h
@@ -545,7 +545,7 @@ typedef struct SDL_GpuVertexBinding
     Uint32 binding;
     Uint32 stride;
     SDL_GpuVertexInputRate inputRate;
-    Uint32 stepRate;
+    Uint32 instanceStepRate; /* ignored unless inputRate is INSTANCE */
 } SDL_GpuVertexBinding;
 
 typedef struct SDL_GpuVertexAttribute

diff --git a/src/gpu/d3d11/SDL_gpu_d3d11.c b/src/gpu/d3d11/SDL_gpu_d3d11.c
@@ -1382,7 +1382,7 @@ static ID3D11InputLayout *D3D11_INTERNAL_FetchInputLayout(
             inputState.vertexBindingCount);
         elementDescs[i].InputSlotClass = SDLToD3D11_VertexInputRate[inputState.vertexBindings[bindingIndex].inputRate];
         /* The spec requires this to be 0 for per-vertex data */
-        elementDescs[i].InstanceDataStepRate = (inputState.vertexBindings[bindingIndex].inputRate == SDL_GPU_VERTEXINPUTRATE_INSTANCE ? inputState.vertexBindings[bindingIndex].stepRate : 0);
+        elementDescs[i].InstanceDataStepRate = (inputState.vertexBindings[bindingIndex].inputRate == SDL_GPU_VERTEXINPUTRATE_INSTANCE) ? inputState.vertexBindings[bindingIndex].instanceStepRate : 0;
 
         elementDescs[i].SemanticIndex = inputState.vertexAttributes[i].location;
         elementDescs[i].SemanticName = "TEXCOORD";

diff --git a/src/gpu/d3d12/SDL_gpu_d3d12.c b/src/gpu/d3d12/SDL_gpu_d3d12.c
@@ -2424,7 +2424,7 @@ static SDL_bool D3D12_INTERNAL_ConvertVertexInputState(SDL_GpuVertexInputState v
         desc[i].InputSlot = attribute.binding;
         desc[i].AlignedByteOffset = attribute.offset;
         desc[i].InputSlotClass = SDLToD3D12_InputRate[vertexInputState.vertexBindings[attribute.binding].inputRate];
-        desc[i].InstanceDataStepRate = vertexInputState.vertexBindings[attribute.binding].stepRate;
+        desc[i].InstanceDataStepRate = (vertexInputState.vertexBindings[attribute.binding].inputRate == SDL_GPU_VERTEXINPUTRATE_INSTANCE) ? vertexInputState.vertexBindings[attribute.binding].instanceStepRate : 0;
     }
 
     return SDL_TRUE;

diff --git a/src/gpu/metal/SDL_gpu_metal.m b/src/gpu/metal/SDL_gpu_metal.m
@@ -1062,6 +1062,7 @@ static void METAL_ReleaseGraphicsPipeline(
             for (Uint32 i = 0; i < pipelineCreateInfo->vertexInputState.vertexBindingCount; i += 1) {
                 binding = METAL_INTERNAL_GetVertexBufferIndex(pipelineCreateInfo->vertexInputState.vertexBindings[i].binding);
                 vertexDescriptor.layouts[binding].stepFunction = SDLToMetal_StepFunction[pipelineCreateInfo->vertexInputState.vertexBindings[i].inputRate];
+                vertexDescriptor.layouts[binding].stepRate = (pipelineCreateInfo->vertexInputState.vertexBindings[i].inputRate == SDL_GPU_VERTEXINPUTRATE_INSTANCE) ? pipelineCreateInfo->vertexInputState.vertexBindings[i].instanceStepRate : 1;
                 vertexDescriptor.layouts[binding].stride = pipelineCreateInfo->vertexInputState.vertexBindings[i].stride;
             }
 

diff --git a/src/gpu/vulkan/SDL_gpu_vulkan.c b/src/gpu/vulkan/SDL_gpu_vulkan.c
@@ -6457,7 +6457,7 @@ static SDL_GpuGraphicsPipeline *VULKAN_CreateGraphicsPipeline(
         for (i = 0; i < pipelineCreateInfo->vertexInputState.vertexBindingCount; i += 1) {
             if (pipelineCreateInfo->vertexInputState.vertexBindings[i].inputRate == SDL_GPU_VERTEXINPUTRATE_INSTANCE) {
                 divisorDescriptions[divisorDescriptionCount].binding = pipelineCreateInfo->vertexInputState.vertexBindings[i].binding;
-                divisorDescriptions[divisorDescriptionCount].divisor = pipelineCreateInfo->vertexInputState.vertexBindings[i].stepRate;
+                divisorDescriptions[divisorDescriptionCount].divisor = pipelineCreateInfo->vertexInputState.vertexBindings[i].instanceStepRate;
 
                 divisorDescriptionCount += 1;
             }

diff --git a/test/testgpu_spinning_cube.c b/test/testgpu_spinning_cube.c
@@ -574,7 +574,7 @@ init_render_state(int msaa)
 
     vertex_binding.binding = 0;
     vertex_binding.inputRate = SDL_GPU_VERTEXINPUTRATE_VERTEX;
-    vertex_binding.stepRate = 0;
+    vertex_binding.instanceStepRate = 0;
     vertex_binding.stride = sizeof(VertexData);
 
     vertex_attributes[0].binding = 0;