Metal: Apply BlendState to RenderPipeline

src/backend/metal/RenderPipelineMTL.mm

@@ -14,11 +14,13 @@
 
 #include "backend/metal/RenderPipelineMTL.h"
 
+#include "backend/metal/BlendStateMTL.h"
 #include "backend/metal/DepthStencilStateMTL.h"
 #include "backend/metal/InputStateMTL.h"
 #include "backend/metal/MetalBackend.h"
 #include "backend/metal/PipelineLayoutMTL.h"
 #include "backend/metal/ShaderModuleMTL.h"
+#include "backend/metal/TextureMTL.h"
 
 namespace backend {
 namespace metal {
@@ -78,9 +80,23 @@ namespace metal {
             }
         }
 
-        // TODO(cwallez@chromium.org): get the attachment formats from the subpass
-        descriptor.colorAttachments[0].pixelFormat = MTLPixelFormatRGBA8Unorm;
-        descriptor.depthAttachmentPixelFormat = MTLPixelFormatDepth32Float;
+        RenderPass* renderPass = ToBackend(GetRenderPass());
+        auto& subpassInfo = renderPass->GetSubpassInfo(GetSubPass());
+
+        if (subpassInfo.depthStencilAttachmentSet) {
+            const auto& attachmentInfo = renderPass->GetAttachmentInfo(subpassInfo.depthStencilAttachment);
+            descriptor.depthAttachmentPixelFormat = MetalPixelFormat(attachmentInfo.format);
+            descriptor.stencilAttachmentPixelFormat = MetalPixelFormat(attachmentInfo.format);
+        }
+
+        for (unsigned int attachmentSlot : IterateBitSet(subpassInfo.colorAttachmentsSet)) {
+            uint32_t attachment = subpassInfo.colorAttachments[attachmentSlot];
+            const auto& attachmentInfo = renderPass->GetAttachmentInfo(attachment);
+
+            descriptor.colorAttachments[attachmentSlot].pixelFormat = MetalPixelFormat(attachmentInfo.format);
+            ToBackend(GetBlendState(attachmentSlot))->ApplyBlendState(descriptor.colorAttachments[attachmentSlot]);
+        }
+
         descriptor.inputPrimitiveTopology = MTLInputPrimitiveTopology(GetPrimitiveTopology());
 
         InputState* inputState = ToBackend(GetInputState());

src/backend/metal/TextureMTL.h

@@ -22,6 +22,8 @@
 namespace backend {
 namespace metal {
 
+    MTLPixelFormat MetalPixelFormat(nxt::TextureFormat format);
+
     class Texture : public TextureBase {
         public:
             Texture(TextureBuilder* builder);

src/backend/metal/TextureMTL.mm

@@ -19,7 +19,6 @@
 namespace backend {
 namespace metal {
 
-    namespace {
     MTLPixelFormat MetalPixelFormat(nxt::TextureFormat format) {
         switch (format) {
             case nxt::TextureFormat::R8G8B8A8Unorm:
@@ -29,6 +28,7 @@ namespace metal {
         }
     }
 
+    namespace {
         MTLTextureUsage MetalTextureUsage(nxt::TextureUsageBit usage) {
             MTLTextureUsage result = MTLTextureUsageUnknown; // This is 0