implemented copy surface as draw for metal gpu backend

Bug: skia:
Change-Id: Ie61bd6ad9f288b8a025d44f887a0954101a7d710
Reviewed-on: https://skia-review.googlesource.com/142687
Commit-Queue: Timothy Liang <timliang@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/src/gpu/mtl/GrMtlCopyPipelineState.mm b/src/gpu/mtl/GrMtlCopyPipelineState.mm
new file mode 100644
index 0000000000..27b52e60f2
--- /dev/null
+++ b/src/gpu/mtl/GrMtlCopyPipelineState.mm
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrMtlCopyPipelineState.h"
+#include "GrMtlGpu.h"
+
+GrMtlCopyPipelineState* GrMtlCopyPipelineState::CreateCopyPipelineState(
+        GrMtlGpu* gpu,
+        MTLPixelFormat dstPixelFormat,
+        id<MTLFunction> vertexFunction,
+        id<MTLFunction> fragmentFunction,
+        MTLVertexDescriptor* vertexDescriptor) {
+
+    // Create pipeline state for copy as draw
+    MTLRenderPipelineDescriptor* pipelineDescriptor = [[MTLRenderPipelineDescriptor alloc] init];
+    pipelineDescriptor.vertexFunction = vertexFunction;
+    pipelineDescriptor.fragmentFunction = fragmentFunction;
+    pipelineDescriptor.vertexDescriptor = vertexDescriptor;
+    pipelineDescriptor.colorAttachments[0].pixelFormat = dstPixelFormat;
+
+    NSError* error = nil;
+    id<MTLRenderPipelineState> pipelineState =
+            [gpu->device() newRenderPipelineStateWithDescriptor: pipelineDescriptor
+                                                          error: &error];
+    if (error) {
+        SkDebugf("Error creating pipeline: %s\n",
+                 [[error localizedDescription] cStringUsingEncoding: NSASCIIStringEncoding]);
+        return nil;
+    }
+
+    SkASSERT(pipelineState);
+    return new GrMtlCopyPipelineState(pipelineState, dstPixelFormat);
+}