Adding linear interpolation to rgb->yuv conversion

src/gpu/SkGr.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.
  */
 
 #include "SkGr.h"
 
 #include "GrXferProcessor.h"
@@ skipping 347 matching lines @@
             SkYUVPlanesCache::Add(pixelRef->getGenerationID(), cachedData, &yuvInfo);
         }
     }
 
     GrSurfaceDesc yuvDesc;
     yuvDesc.fConfig = kAlpha_8_GrPixelConfig;
     SkAutoTUnref<GrTexture> yuvTextures[3];
     for (int i = 0; i < 3; ++i) {
         yuvDesc.fWidth  = yuvInfo.fSize[i].fWidth;
         yuvDesc.fHeight = yuvInfo.fSize[i].fHeight;
-        yuvTextures[i].reset(
-            ctx->refScratchTexture(yuvDesc, GrContext::kApprox_ScratchTexMatch));
+        bool needsExactTexture =
+            (yuvDesc.fWidth  != yuvInfo.fSize[0].fWidth) ||
+            (yuvDesc.fHeight != yuvInfo.fSize[0].fHeight);
+        yuvTextures[i].reset(ctx->refScratchTexture(yuvDesc,
+            needsExactTexture ? GrContext::kExact_ScratchTexMatch :
+                                GrContext::kApprox_ScratchTexMatch));
         if (!yuvTextures[i] ||
             !yuvTextures[i]->writePixels(0, 0, yuvDesc.fWidth, yuvDesc.fHeight,
                                          yuvDesc.fConfig, planes[i], yuvInfo.fRowBytes[i])) {
             return NULL;
         }
     }
 
     GrSurfaceDesc rtDesc = desc;
     rtDesc.fFlags = rtDesc.fFlags | kRenderTarget_GrSurfaceFlag;
 
@@ skipping 336 matching lines @@
         if (shader->asFragmentProcessor(context, skPaint, viewM, NULL, &paintColor, &fp) && fp) {
             grPaint->addColorProcessor(fp)->unref();
             constantColor = false;
         }
     }
 
     // The grcolor is automatically set when calling asFragmentProcessor.
     // If the shader can be seen as an effect it returns true and adds its effect to the grpaint.
     SkPaint2GrPaintNoShader(context, rt, skPaint, paintColor, constantColor, grPaint);
 }