Image filters: fix srcOffset handling in asFragmentProcessor() path.

src/core/SkImageFilter.cpp

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImageFilter.h"
 
 #include "SkBitmap.h"
@@ skipping 316 matching lines @@
     SkASSERT(fInputCount == 1);
     SkIPoint srcOffset = SkIPoint::Make(0, 0);
     if (!this->filterInputGPU(0, proxy, src, ctx, &input, &srcOffset)) {
         return false;
     }
     GrTexture* srcTexture = input.getTexture();
     SkIRect bounds;
     if (!this->applyCropRect(ctx, proxy, input, &srcOffset, &bounds, &input)) {
         return false;
     }
-    SkRect srcRect = SkRect::Make(bounds);
-    SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
     GrContext* context = srcTexture->getContext();
 
     GrSurfaceDesc desc;
     desc.fFlags = kRenderTarget_GrSurfaceFlag,
     desc.fWidth = bounds.width();
     desc.fHeight = bounds.height();
     desc.fConfig = kRGBA_8888_GrPixelConfig;
 
     SkAutoTUnref<GrTexture> dst(context->textureProvider()->createApproxTexture(desc));
     if (!dst) {
         return false;
     }
 
-    // setup new clip
-    GrClip clip(dstRect);
-
     GrFragmentProcessor* fp;
     offset->fX = bounds.left();
     offset->fY = bounds.top();
     bounds.offset(-srcOffset);
     SkMatrix matrix(ctx.ctm());
     matrix.postTranslate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
     GrPaint paint;
     if (this->asFragmentProcessor(&fp, srcTexture, matrix, bounds)) {
         SkASSERT(fp);
         paint.addColorFragmentProcessor(fp)->unref();
         paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
 
         SkAutoTUnref<GrDrawContext> drawContext(context->drawContext(dst->asRenderTarget()));
         if (drawContext) {
+            SkRect srcRect = SkRect::Make(bounds);
+            SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
+            GrClip clip(dstRect);
             drawContext->fillRectToRect(clip, paint, SkMatrix::I(), dstRect, srcRect);
 
             GrWrapTextureInBitmap(dst, bounds.width(), bounds.height(), false, result);
             return true;
         }
     }
 #endif
     return false;
 }
 
@@ skipping 293 matching lines @@
     }
     return dev;
 }
 
 bool SkImageFilter::DeviceProxy::filterImage(const SkImageFilter* filter, const SkBitmap& src,
                                        const SkImageFilter::Context& ctx,
                                        SkBitmap* result, SkIPoint* offset) {
     return fDevice->filterImage(filter, src, ctx, result, offset);
 }