[graphite] Add CommandBuffer creation

Bug: skia:12466
Change-Id: I3a22d03e5042a94f2bf6d379b2fff17f0b48edb3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/455217
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>

experimental/graphite/src/CommandBuffer.h

@@ -12,7 +12,7 @@ namespace skgpu {
 
 class CommandBuffer {
 public:
-    virtual ~CommandBuffer() = default;
+    virtual ~CommandBuffer() {}
 
 protected:
     CommandBuffer();

experimental/graphite/src/ResourceProvider.cpp

@@ -18,12 +18,6 @@ ResourceProvider::ResourceProvider() {
 ResourceProvider::~ResourceProvider() {
 }
 
-std::unique_ptr<CommandBuffer> ResourceProvider::createCommandBuffer() {
-    auto cb = this->onCreateCommandBuffer();
-
-    return cb;
-}
-
 Pipeline* ResourceProvider::findOrCreatePipeline(const PipelineDesc& desc) {
     // TODO: look through cache for matching pipeline
 
@@ -34,8 +28,4 @@ Pipeline* ResourceProvider::findOrCreatePipeline(const PipelineDesc& desc) {
     return pso;
 }
 
-std::unique_ptr<CommandBuffer> onCreateCommandBuffer() {
-    return nullptr;
-}
-
 } // namespace skgpu

experimental/graphite/src/ResourceProvider.h

@@ -20,13 +20,12 @@ class ResourceProvider {
 public:
     virtual ~ResourceProvider();
 
-    std::unique_ptr<CommandBuffer> createCommandBuffer();
+    virtual std::unique_ptr<CommandBuffer> createCommandBuffer() { return nullptr; }
     Pipeline* findOrCreatePipeline(const PipelineDesc&);
 
 protected:
     ResourceProvider();
 
-    virtual std::unique_ptr<CommandBuffer> onCreateCommandBuffer();
     virtual Pipeline* onCreatePipeline() { return nullptr; }
 
 private:

experimental/graphite/src/mtl/MtlCommandBuffer.h

@@ -10,16 +10,25 @@
 
 #include "experimental/graphite/src/CommandBuffer.h"
 
+#include <memory>
+
+#include "include/core/SkTypes.h"
+#include "include/ports/SkCFObject.h"
+
 #import <Metal/Metal.h>
 
 namespace skgpu::mtl {
 
 class CommandBuffer final : public skgpu::CommandBuffer {
 public:
-    CommandBuffer();
+    static std::unique_ptr<CommandBuffer> Make(id<MTLCommandQueue>);
     ~CommandBuffer() override {}
 
 private:
+    CommandBuffer(sk_cfp<id<MTLCommandBuffer>> cmdBuffer)
+        : fCommandBuffer(std::move(cmdBuffer)) {}
+
+    sk_cfp<id<MTLCommandBuffer>> fCommandBuffer;
 };
 
 } // namespace skgpu::mtl

experimental/graphite/src/mtl/MtlCommandBuffer.mm

@@ -9,7 +9,24 @@
 
 namespace skgpu::mtl {
 
-CommandBuffer::CommandBuffer() {
+std::unique_ptr<CommandBuffer> CommandBuffer::Make(id<MTLCommandQueue> queue) {
+    sk_cfp<MTLCommandBufferDescriptor*> desc([[MTLCommandBufferDescriptor alloc] init]);
+    (*desc).retainedReferences = NO;
+#ifdef SK_ENABLE_MTL_DEBUG_INFO
+    (*desc).errorOptions = MTLCommandBufferErrorOptionEncoderExecutionStatus;
+#endif
+
+    // We add a retain here because the command buffer is set to autorelease (not alloc or copy)
+    sk_cfp<id<MTLCommandBuffer>> cmdBuffer([[queue commandBufferWithDescriptor:desc.get()] retain]);
+    if (cmdBuffer == nil) {
+        return nullptr;
+    }
+
+#ifdef SK_ENABLE_MTL_DEBUG_INFO
+     (*cmdBuffer).label = @"CommandBuffer::Make";
+#endif
+
+    return std::unique_ptr<CommandBuffer>(new CommandBuffer(std::move(cmdBuffer)));
 }
 
 } // namespace skgpu::mtl

experimental/graphite/src/mtl/MtlGpu.h

@@ -25,6 +25,7 @@ public:
     ~Gpu() override;
 
     id<MTLDevice> device() const { return fDevice.get(); }
+    id<MTLCommandQueue> queue() const { return fQueue.get(); }
 
     const Caps& mtlCaps() const { return static_cast<const Caps&>(*this->caps()); }
 

experimental/graphite/src/mtl/MtlResourceProvider.h

@@ -12,14 +12,23 @@
 
 #import <Metal/Metal.h>
 
+namespace skgpu {
+class CommandBuffer;
+}
+
 namespace skgpu::mtl {
 
+class Gpu;
+
 class ResourceProvider final : public skgpu::ResourceProvider {
 public:
-    ResourceProvider();
+    ResourceProvider(const Gpu*);
     ~ResourceProvider() override {}
 
+    std::unique_ptr<skgpu::CommandBuffer> createCommandBuffer() override;
+
 private:
+    const Gpu* fGpu;
 };
 
 } // namespace skgpu::mtl

experimental/graphite/src/mtl/MtlResourceProvider.mm

@@ -7,9 +7,17 @@
 
 #include "experimental/graphite/src/mtl/MtlResourceProvider.h"
 
+#include "experimental/graphite/src/mtl/MtlCommandBuffer.h"
+#include "experimental/graphite/src/mtl/MtlGpu.h"
+
 namespace skgpu::mtl {
 
-ResourceProvider::ResourceProvider() {
+ResourceProvider::ResourceProvider(const Gpu* gpu)
+    : fGpu(gpu) {
+}
+
+std::unique_ptr<skgpu::CommandBuffer> ResourceProvider::createCommandBuffer() {
+    return CommandBuffer::Make(fGpu->queue());
 }
 
 } // namespace skgpu::mtl