Use blitframebuffer to implement copySurface.

src/gpu/GrDrawTarget.cpp

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 
@@ skipping 393 matching lines @@
         return false;
     }
     return true;
 }
 
 bool GrDrawTarget::setupDstReadIfNecessary(DrawInfo* info) {
     if (!this->getDrawState().willEffectReadDst()) {
         return true;
     }
     GrRenderTarget* rt = this->drawState()->getRenderTarget();
-    // If the dst is not a texture then we don't currently have a way of copying the
-    // texture. TODO: API-specific impl of onCopySurface that can handle more cases.
-    if (NULL == rt->asTexture()) {
-        GrPrintf("Reading Dst of non-texture render target is not currently supported.\n");
-        return false;
-    }
 
     const GrClipData* clip = this->getClip();
     GrIRect copyRect;
     clip->getConservativeBounds(this->getDrawState().getRenderTarget(), &copyRect);
     SkIRect drawIBounds;
     if (info->getDevIBounds(&drawIBounds)) {
         if (!copyRect.intersect(drawIBounds)) {
 #if GR_DEBUG
             GrPrintf("Missed an early reject. Bailing on draw from setupDstReadIfNecessary.\n");
 #endif
             return false;
         }
     } else {
 #if GR_DEBUG
         //GrPrintf("No dev bounds when dst copy is made.\n");
 #endif
     }
 
-    // The draw will resolve dst if it has MSAA. Two things to consider in the future:
-    // 1) to make the dst values be pre-resolve we'd need to be able to copy to MSAA
-    // texture and sample it correctly in the shader. 2) If 1 isn't available then we
-    // should just resolve and use the resolved texture directly rather than making a
-    // copy of it.
+    // MSAA consideration: When there is support for reading MSAA samples in the shader we could
+    // have per-sample dst values by making the copy multisampled.
     GrTextureDesc desc;
     desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
     desc.fWidth = copyRect.width();
     desc.fHeight = copyRect.height();
     desc.fSampleCnt = 0;
     desc.fConfig = rt->config();
 
     GrAutoScratchTexture ast(fContext, desc, GrContext::kApprox_ScratchTexMatch);
 
     if (NULL == ast.texture()) {
@@ skipping 486 matching lines @@
     GrPrintf("HW AA Lines Support         : %s\n", gNY[fHWAALineSupport]);
     GrPrintf("Shader Derivative Support   : %s\n", gNY[fShaderDerivativeSupport]);
     GrPrintf("Geometry Shader Support     : %s\n", gNY[fGeometryShaderSupport]);
     GrPrintf("Dual Source Blending Support: %s\n", gNY[fDualSourceBlendingSupport]);
     GrPrintf("Buffer Lock Support         : %s\n", gNY[fBufferLockSupport]);
     GrPrintf("Path Stenciling Support     : %s\n", gNY[fPathStencilingSupport]);
     GrPrintf("Max Texture Size            : %d\n", fMaxTextureSize);
     GrPrintf("Max Render Target Size      : %d\n", fMaxRenderTargetSize);
     GrPrintf("Max Sample Count            : %d\n", fMaxSampleCount);
 }