Swap render target instead of creating a new gpu device for surface copy-on-write

src/gpu/SkGpuDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGpuDevice.h"
 
 #include "effects/GrBicubicEffect.h"
@@ skipping 20 matching lines @@
 #include "SkImageFilter.h"
 #include "SkLayerInfo.h"
 #include "SkMaskFilter.h"
 #include "SkPathEffect.h"
 #include "SkPicture.h"
 #include "SkPictureData.h"
 #include "SkRecord.h"
 #include "SkRRect.h"
 #include "SkStroke.h"
 #include "SkSurface.h"
+#include "SkSurface_Gpu.h"
 #include "SkTLazy.h"
 #include "SkUtils.h"
 #include "SkVertState.h"
 #include "SkXfermode.h"
 #include "SkErrorInternals.h"
 
 #if SK_SUPPORT_GPU
 
 enum { kDefaultImageFilterCacheSize = 32 * 1024 * 1024 };
 
@@ skipping 107 matching lines @@
 
     SkImageInfo info = rt->surfacePriv().info();
     SkPixelRef* pr = SkNEW_ARGS(SkGrPixelRef, (info, rt));
     fLegacyBitmap.setInfo(info);
     fLegacyBitmap.setPixelRef(pr)->unref();
 
     bool useDFT = fSurfaceProps.isUseDistanceFieldFonts();
     fTextContext = fContext->createTextContext(fRenderTarget, this->getLeakyProperties(), useDFT);
 }
 
-SkGpuDevice* SkGpuDevice::Create(GrContext* context, SkSurface::Budgeted budgeted,
-                                 const SkImageInfo& origInfo, int sampleCount,
-                                 const SkSurfaceProps* props, unsigned flags) {
+GrRenderTarget* SkGpuDevice::CreateRenderTarget(GrContext* context, SkSurface::Budgeted budgeted,
+                                                const SkImageInfo& origInfo, int sampleCount) {
     if (kUnknown_SkColorType == origInfo.colorType() ||
         origInfo.width() < 0 || origInfo.height() < 0) {
         return NULL;
     }
 
     if (!context) {
         return NULL;
     }
 
     SkColorType ct = origInfo.colorType();
     SkAlphaType at = origInfo.alphaType();
     if (kRGB_565_SkColorType == ct) {
         at = kOpaque_SkAlphaType;  // force this setting
     } else if (ct != kBGRA_8888_SkColorType && ct != kRGBA_8888_SkColorType) {
         // Fall back from whatever ct was to default of kRGBA or kBGRA which is aliased as kN32
         ct = kN32_SkColorType;
     }
     if (kOpaque_SkAlphaType != at) {
         at = kPremul_SkAlphaType;  // force this setting
     }
     const SkImageInfo info = SkImageInfo::Make(origInfo.width(), origInfo.height(), ct, at);
 
     GrSurfaceDesc desc;
     desc.fFlags = kRenderTarget_GrSurfaceFlag;
     desc.fWidth = info.width();
     desc.fHeight = info.height();
     desc.fConfig = SkImageInfo2GrPixelConfig(info);
     desc.fSampleCnt = sampleCount;
+    GrTexture* texture = context->createTexture(desc, SkToBool(budgeted), NULL, 0);
+    if (NULL == texture) {
+        return NULL;
+    }
+    SkASSERT(NULL != texture->asRenderTarget());
+    return texture->asRenderTarget();
+}
 
-    SkAutoTUnref<GrTexture> texture(context->createTexture(desc, SkToBool(budgeted), NULL, 0));
-    if (!texture) {
+SkGpuDevice* SkGpuDevice::Create(GrContext* context, SkSurface::Budgeted budgeted,
+                                 const SkImageInfo& info, int sampleCount,
+                                 const SkSurfaceProps* props, unsigned flags) {
+
+    SkAutoTUnref<GrRenderTarget> rt(CreateRenderTarget(context, budgeted, info, sampleCount));
+    if (!rt) {
         return NULL;
     }
 
-    return SkNEW_ARGS(SkGpuDevice, (texture->asRenderTarget(), props, flags));
+    return SkNEW_ARGS(SkGpuDevice, (rt, props, flags));
 }
 
 SkGpuDevice::~SkGpuDevice() {
     if (fDrawProcs) {
         delete fDrawProcs;
     }
 
     delete fTextContext;
 
     // The GrContext takes a ref on the target. We don't want to cause the render
@@ skipping 88 matching lines @@
 }
 
 void SkGpuDevice::clearAll() {
     GrColor color = 0;
     GR_CREATE_TRACE_MARKER_CONTEXT("SkGpuDevice::clearAll", fContext);
     SkIRect rect = SkIRect::MakeWH(this->width(), this->height());
     fContext->clear(&rect, color, true, fRenderTarget);
     fNeedClear = false;
 }
 
+void SkGpuDevice::swapRenderTarget(GrRenderTarget* newRenderTarget) {
+    SkASSERT(!fNeedClear);
+    if (fContext->getRenderTarget() == fRenderTarget) {
+        fContext->setRenderTarget(NULL);
+    }
+    SkRefCnt_SafeAssign(fRenderTarget, newRenderTarget);
+    SkASSERT(newRenderTarget->surfacePriv().info() == fLegacyBitmap.info());
+    SkPixelRef* pr = SkNEW_ARGS(SkGrPixelRef, (newRenderTarget->surfacePriv().info(),
+                                               newRenderTarget));
+    fLegacyBitmap.setPixelRef(pr)->unref();
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 SK_COMPILE_ASSERT(SkShader::kNone_BitmapType == 0, shader_type_mismatch);
 SK_COMPILE_ASSERT(SkShader::kDefault_BitmapType == 1, shader_type_mismatch);
 SK_COMPILE_ASSERT(SkShader::kRadial_BitmapType == 2, shader_type_mismatch);
 SK_COMPILE_ASSERT(SkShader::kSweep_BitmapType == 3, shader_type_mismatch);
 SK_COMPILE_ASSERT(SkShader::kTwoPointRadial_BitmapType == 4,
                   shader_type_mismatch);
 SK_COMPILE_ASSERT(SkShader::kTwoPointConical_BitmapType == 5,
                   shader_type_mismatch);
@@ skipping 1580 matching lines @@
 #endif
 }
 
 SkImageFilter::Cache* SkGpuDevice::getImageFilterCache() {
     // We always return a transient cache, so it is freed after each
     // filter traversal.
     return SkImageFilter::Cache::Create(kDefaultImageFilterCacheSize);
 }
 
 #endif