Add support for creating a GrContext backed by Metal.

Also adds the support code to allow our TestContext to create a Metal
backend.

Bug: skia:
Change-Id: Ia850687019d79b897bb16e2c151f4f8526721ad9
Reviewed-on: https://skia-review.googlesource.com/22644
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>

6 files changed, 68 insertions, 31 deletions

diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index 8cad6be20b..2f3c30d997 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -28,6 +28,10 @@
 #include "effects/GrConfigConversionEffect.h"
 #include "text/GrTextBlobCache.h"
 
+#ifdef SK_METAL
+#include "mtl/GrMtlTrampoline.h"
+#endif
+
 #define ASSERT_OWNED_PROXY(P) \
 SkASSERT(!(P) || !((P)->priv().peekTexture()) || (P)->priv().peekTexture()->getContext() == this)
 #define ASSERT_OWNED_PROXY_PRIV(P) \
@@ -61,6 +65,21 @@ GrContext* GrContext::Create(GrBackend backend, GrBackendContext backendContext,
     return context.release();
 }
 
+#ifdef SK_METAL
+sk_sp<GrContext> GrContext::MakeMetal(void* device, void* queue, const GrContextOptions& options) {
+    sk_sp<GrContext> context(new GrContext);
+    context->fGpu = GrMtlTrampoline::CreateGpu(context.get(), options, device, queue);
+    if (!context->fGpu) {
+        return nullptr;
+    }
+    context->fBackend = kMetal_GrBackend;
+    if (!context->init(options)) {
+        return nullptr;
+    }
+    return context;
+}
+#endif
+
 static int32_t gNextID = 1;
 static int32_t next_id() {
     int32_t id;
@@ -89,7 +108,11 @@ bool GrContext::init(GrBackend backend, GrBackendContext backendContext,
     if (!fGpu) {
         return false;
     }
+    return this->init(options);
+}
 
+bool GrContext::init(const GrContextOptions& options) {
+    ASSERT_SINGLE_OWNER
     fCaps = SkRef(fGpu->caps());
     fResourceCache = new GrResourceCache(fCaps, fUniqueID);
     fResourceProvider = new GrResourceProvider(fGpu, fResourceCache, &fSingleOwner);
diff --git a/src/gpu/GrGpuFactory.cpp b/src/gpu/GrGpuFactory.cpp
index 7cfec4a900..1fc19c144a 100644
--- a/src/gpu/GrGpuFactory.cpp
+++ b/src/gpu/GrGpuFactory.cpp
@@ -12,9 +12,6 @@
 #ifdef SK_VULKAN
 #include "vk/GrVkGpu.h"
 #endif
-#ifdef SK_METAL
-#include "mtl/GrMtlTrampoline.h"
-#endif
 
 GrGpu* GrGpu::Create(GrBackend backend,
                      GrBackendContext backendContext,
@@ -27,10 +24,6 @@ GrGpu* GrGpu::Create(GrBackend backend,
         case kVulkan_GrBackend:
             return GrVkGpu::Create(backendContext, options, context);
 #endif
-#ifdef SK_METAL
-        case kMetal_GrBackend:
-            return GrMtlTrampoline::CreateGpu(backendContext, options, context);
-#endif
         case kMock_GrBackend:
             return GrMockGpu::Create(backendContext, options, context);
         default:
diff --git a/src/gpu/mtl/GrMtlGpu.h b/src/gpu/mtl/GrMtlGpu.h
index 7ec9907675..b63f9080be 100644
--- a/src/gpu/mtl/GrMtlGpu.h
+++ b/src/gpu/mtl/GrMtlGpu.h
@@ -16,11 +16,12 @@
 #import <Metal/Metal.h>
 
 class GrSemaphore;
+struct GrMtlBackendContext;
 
 class GrMtlGpu : public GrGpu {
 public:
-    static GrGpu* Create(GrBackendContext backendContext, const GrContextOptions& options,
-                         GrContext* context);
+    static GrGpu* Create(GrContext* context, const GrContextOptions& options,
+                         id<MTLDevice> device, id<MTLCommandQueue> queue);
 
     ~GrMtlGpu() override {}
 
@@ -59,19 +60,8 @@ public:
     sk_sp<GrSemaphore> prepareTextureForCrossContextUsage(GrTexture*) override { return nullptr; }
 
 private:
-    GrMtlGpu(GrContext* context, const GrContextOptions& options) : INHERITED(context) {
-        id<MTLDevice> device = MTLCreateSystemDefaultDevice();
-
-        MTLTextureDescriptor* txDesc = [[MTLTextureDescriptor alloc] init];
-        txDesc.textureType = MTLTextureType3D;
-        txDesc.height = 64;
-        txDesc.width = 64;
-        txDesc.depth = 64;
-        txDesc.pixelFormat = MTLPixelFormatBGRA8Unorm;
-        txDesc.arrayLength = 1;
-        txDesc.mipmapLevelCount = 1;
-        fTestHeaderTexture = [device newTextureWithDescriptor:txDesc];
-    }
+    GrMtlGpu(GrContext* context, const GrContextOptions& options,
+             id<MTLDevice> device, id<MTLCommandQueue> queue);
 
     void onResetContext(uint32_t resetBits) override {}
 
@@ -146,7 +136,9 @@ private:
     bool isTestingOnlyBackendTexture(GrBackendObject ) const override { return false; }
     void deleteTestingOnlyBackendTexture(GrBackendObject, bool abandonTexture) override {}
 
-    id<MTLTexture> fTestHeaderTexture;
+    id<MTLDevice> fDevice;
+    id<MTLCommandQueue> fQueue;
+
 
     typedef GrGpu INHERITED;
 };
diff --git a/src/gpu/mtl/GrMtlGpu.mm b/src/gpu/mtl/GrMtlGpu.mm
index 7d9339cf29..986bb8a6f7 100644
--- a/src/gpu/mtl/GrMtlGpu.mm
+++ b/src/gpu/mtl/GrMtlGpu.mm
@@ -11,8 +11,31 @@
 #error This file must be compiled with Arc. Use -fobjc-arc flag
 #endif
 
-GrGpu* GrMtlGpu::Create(GrBackendContext backendContext, const GrContextOptions& options,
-                        GrContext* context) {
-    return nullptr;
+GrGpu* GrMtlGpu::Create(GrContext* context, const GrContextOptions& options,
+                        id<MTLDevice> device, id<MTLCommandQueue> queue) {
+    if (!device || !queue) {
+        return nullptr;
+    }
+    return new GrMtlGpu(context, options, device, queue);
 }
 
+GrMtlGpu::GrMtlGpu(GrContext* context, const GrContextOptions& options,
+                   id<MTLDevice> device, id<MTLCommandQueue> queue)
+        : INHERITED(context)
+        , fDevice(device)
+        , fQueue(queue) {
+    MTLTextureDescriptor* txDesc = [[MTLTextureDescriptor alloc] init];
+    txDesc.textureType = MTLTextureType3D;
+    txDesc.height = 64;
+    txDesc.width = 64;
+    txDesc.depth = 64;
+    txDesc.pixelFormat = MTLPixelFormatRGBA8Unorm;
+    txDesc.arrayLength = 1;
+    txDesc.mipmapLevelCount = 1;
+    id<MTLTexture> testTexture = [fDevice newTextureWithDescriptor:txDesc];
+    // To get ride of unused var warning
+    int width = [testTexture width];
+    SkDebugf("width: %d\n", width);
+    // Unused queue warning fix
+    SkDebugf("ptr to queue: %p\n", fQueue);
+}
diff --git a/src/gpu/mtl/GrMtlTrampoline.h b/src/gpu/mtl/GrMtlTrampoline.h
index acce98cd1f..531a4ce00c 100644
--- a/src/gpu/mtl/GrMtlTrampoline.h
+++ b/src/gpu/mtl/GrMtlTrampoline.h
@@ -20,8 +20,10 @@ struct GrContextOptions;
  */
 class GrMtlTrampoline {
 public:
-    static GrGpu* CreateGpu(GrBackendContext backendContext, const GrContextOptions& options,
-                            GrContext* context);
+    static GrGpu* CreateGpu(GrContext* context,
+                            const GrContextOptions& options,
+                            void* device,
+                            void* queue);
 };
 
 #endif
diff --git a/src/gpu/mtl/GrMtlTrampoline.mm b/src/gpu/mtl/GrMtlTrampoline.mm
index ea91ebb827..0f112e4da5 100644
--- a/src/gpu/mtl/GrMtlTrampoline.mm
+++ b/src/gpu/mtl/GrMtlTrampoline.mm
@@ -9,9 +9,13 @@
 
 #include "GrMtlGpu.h"
 
-GrGpu* GrMtlTrampoline::CreateGpu(GrBackendContext backendContext,
+GrGpu* GrMtlTrampoline::CreateGpu(GrContext* context,
                                   const GrContextOptions& options,
-                                  GrContext* context) {
-    return GrMtlGpu::Create(backendContext, options, context);
+                                  void* device,
+                                  void* queue) {
+    return GrMtlGpu::Create(context,
+                            options,
+                            (__bridge_transfer id<MTLDevice>)device,
+                            (__bridge_transfer id<MTLCommandQueue>)queue);
 }