Add support for using glCopyTexSubImage2D when possible to copy surfaces.

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 414 matching lines @@
         }
     } else {
 #if GR_DEBUG
         //GrPrintf("No dev bounds when dst copy is made.\n");
 #endif
     }
 
     // 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;
+    this->initCopySurfaceDstDesc(rt, &desc);
     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()) {
         GrPrintf("Failed to create temporary copy of destination texture.\n");
         return false;
     }
     SkIPoint dstPoint = {0, 0};
     if (this->copySurface(ast.texture(), rt, copyRect, dstPoint)) {
         info->fDstCopy.setTexture(ast.texture());
-        info->fDstCopy.setOffset(copyRect.fLeft, copyRect.fTop);
+        info->fDstCopy.setOffset(copyRect.fLeft, copyRect.fTop);    
         return true;
     } else {
         return false;
     }
 }
 
 void GrDrawTarget::drawIndexed(GrPrimitiveType type,
                                int startVertex,
                                int startIndex,
                                int vertexCount,
@@ skipping 413 matching lines @@
     matrix.postIDiv(tex->width(), tex->height());
     this->drawState()->createTextureEffect(0, tex, matrix);
     SkIRect dstRect = SkIRect::MakeXYWH(dstPoint.fX,
                                         dstPoint.fY,
                                         srcRect.width(),
                                         srcRect.height());
     this->drawSimpleRect(dstRect);
     return true;
 }
 
+void GrDrawTarget::initCopySurfaceDstDesc(const GrSurface* src, GrTextureDesc* desc) {
+    // Make the dst of the copy be a render target because the default copySurface draws to the dst.
+    desc->fOrigin = kDefault_GrSurfaceOrigin;
+    desc->fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
+    desc->fConfig = src->config();
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 SK_DEFINE_INST_COUNT(GrDrawTargetCaps)
 
 void GrDrawTargetCaps::reset() {
     f8BitPaletteSupport = false;
     fNPOTTextureTileSupport = false;
     fTwoSidedStencilSupport = false;
     fStencilWrapOpsSupport = false;
     fHWAALineSupport = false;
@@ skipping 36 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);
 }