Adding a new SkSurface factory for generating surfaces from the scratch texture pool.

src/image/SkSurface_Gpu.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkSurface_Base.h"
 #include "SkImagePriv.h"
 #include "SkCanvas.h"
 #include "SkGpuDevice.h"
 
 class SkSurface_Gpu : public SkSurface_Base {
 public:
     SK_DECLARE_INST_COUNT(SkSurface_Gpu)
 
-    SkSurface_Gpu(GrRenderTarget*);
+    SkSurface_Gpu(GrRenderTarget*, bool cached);
     virtual ~SkSurface_Gpu();
 
     virtual SkCanvas* onNewCanvas() SK_OVERRIDE;
     virtual SkSurface* onNewSurface(const SkImageInfo&) SK_OVERRIDE;
     virtual SkImage* onNewImageSnapshot() SK_OVERRIDE;
     virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y,
                         const SkPaint*) SK_OVERRIDE;
     virtual void onCopyOnWrite(ContentChangeMode) SK_OVERRIDE;
 
 private:
     SkGpuDevice* fDevice;
 
     typedef SkSurface_Base INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
-SkSurface_Gpu::SkSurface_Gpu(GrRenderTarget* renderTarget)
+SkSurface_Gpu::SkSurface_Gpu(GrRenderTarget* renderTarget, bool cached)
         : INHERITED(renderTarget->width(), renderTarget->height()) {
-    fDevice = SkNEW_ARGS(SkGpuDevice, (renderTarget->getContext(), renderTarget));
+    fDevice = SkGpuDevice::Create(renderTarget, cached ? SkGpuDevice::kCached_Flag : 0);
 
     if (kRGB_565_GrPixelConfig != renderTarget->config()) {
         fDevice->clear(0x0);
     }
 }
 
 SkSurface_Gpu::~SkSurface_Gpu() {
     SkSafeUnref(fDevice);
 }
 
@@ skipping 40 matching lines @@
         SkRefCnt_SafeAssign(fDevice, newDevice);
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkSurface* SkSurface::NewRenderTargetDirect(GrRenderTarget* target) {
     if (NULL == target) {
         return NULL;
     }
-    return SkNEW_ARGS(SkSurface_Gpu, (target));
+    return SkNEW_ARGS(SkSurface_Gpu, (target, false));
 }
 
 SkSurface* SkSurface::NewRenderTarget(GrContext* ctx, const SkImageInfo& info, int sampleCount) {
     if (NULL == ctx) {
         return NULL;
     }
 
     SkBitmap::Config config = SkImageInfoToBitmapConfig(info);
 
     GrTextureDesc desc;
     desc.fFlags = kRenderTarget_GrTextureFlagBit | kCheckAllocation_GrTextureFlagBit;
     desc.fWidth = info.fWidth;
     desc.fHeight = info.fHeight;
     desc.fConfig = SkBitmapConfig2GrPixelConfig(config);
     desc.fSampleCnt = sampleCount;
 
     SkAutoTUnref<GrTexture> tex(ctx->createUncachedTexture(desc, NULL, 0));
     if (NULL == tex) {
         return NULL;
     }
 
-    return SkNEW_ARGS(SkSurface_Gpu, (tex->asRenderTarget()));
+    return SkNEW_ARGS(SkSurface_Gpu, (tex->asRenderTarget(), false));
 }
+
+SkSurface* SkSurface::NewScratchRenderTarget(GrContext* ctx, const SkImageInfo& info, int sampleCount) {
+    if (NULL == ctx) {
+        return NULL;
+    }
+
+    SkBitmap::Config config = SkImageInfoToBitmapConfig(info);
+
+    GrTextureDesc desc;
+    desc.fFlags = kRenderTarget_GrTextureFlagBit | kCheckAllocation_GrTextureFlagBit;
+    desc.fWidth = info.fWidth;
+    desc.fHeight = info.fHeight;
+    desc.fConfig = SkBitmapConfig2GrPixelConfig(config);
+    desc.fSampleCnt = sampleCount;
+
+    SkAutoTUnref<GrTexture> tex(ctx->lockAndRefScratchTexture(desc, GrContext::kExact_ScratchTexMatch));
+
+    if (NULL == tex) {
+        return NULL;
+    }
+
+    return SkNEW_ARGS(SkSurface_Gpu, (tex->asRenderTarget(), true));
+}