Fix image filter crop offsets for GPU 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 130 matching lines @@
 
 bool SkImageFilter::canFilterImageGPU() const {
     return this->asNewEffect(NULL, NULL, SkMatrix::I(), SkIRect());
 }
 
 bool SkImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
                                    SkBitmap* result, SkIPoint* offset) {
 #if SK_SUPPORT_GPU
     SkBitmap input;
     SkASSERT(fInputCount == 1);
-    if (!SkImageFilterUtils::GetInputResultGPU(this->getInput(0), proxy, src, ctm, &input, offset)) {
+    SkIPoint srcOffset = SkIPoint::Make(0, 0);
+    if (!SkImageFilterUtils::GetInputResultGPU(this->getInput(0), proxy, src, ctm, &input, &srcOffset)) {

[bsalomon, 2014/02/03 21:31:08]

if all the callers now pass a non-NULL value maybe this should be a required
const& param?

         return false;
     }
     GrTexture* srcTexture = input.getTexture();
     SkIRect bounds;
     src.getBounds(&bounds);
+    bounds.offset(srcOffset);
     if (!this->applyCropRect(&bounds, ctm)) {
         return false;
     }
     SkRect srcRect = SkRect::Make(bounds);
     SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
     GrContext* context = srcTexture->getContext();
 
     GrTextureDesc desc;
     desc.fFlags = kRenderTarget_GrTextureFlagBit,
     desc.fWidth = bounds.width();
     desc.fHeight = bounds.height();
     desc.fConfig = kRGBA_8888_GrPixelConfig;
 
     GrAutoScratchTexture dst(context, desc);
     GrContext::AutoMatrix am;
     am.setIdentity(context);
     GrContext::AutoRenderTarget art(context, dst.texture()->asRenderTarget());
     GrContext::AutoClip acs(context, dstRect);
     GrEffectRef* effect;
+    offset->fX = bounds.left();
+    offset->fY = bounds.top();
+    bounds.offset(-srcOffset);
     SkMatrix matrix(ctm);
     matrix.postTranslate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
     this->asNewEffect(&effect, srcTexture, matrix, bounds);
     SkASSERT(effect);
     SkAutoUnref effectRef(effect);
     GrPaint paint;
     paint.addColorEffect(effect);
     context->drawRectToRect(paint, dstRect, srcRect);
 
     SkAutoTUnref<GrTexture> resultTex(dst.detach());
     SkImageFilterUtils::WrapTexture(resultTex, bounds.width(), bounds.height(), result);
-    offset->fX += bounds.left();
-    offset->fY += bounds.top();
     return true;
 #else
     return false;
 #endif
 }
 
 bool SkImageFilter::applyCropRect(SkIRect* rect, const SkMatrix& matrix) const {
     SkRect cropRect;
     matrix.mapRect(&cropRect, fCropRect.rect());
     SkIRect cropRectI;
@@ skipping 13 matching lines @@
     return true;
 }
 
 bool SkImageFilter::asNewEffect(GrEffectRef**, GrTexture*, const SkMatrix&, const SkIRect&) const {
     return false;
 }
 
 bool SkImageFilter::asColorFilter(SkColorFilter**) const {
     return false;
 }