Implement crop rect for lighting image filters.

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 84 matching lines @@
     SkASSERT(dst);
     return this->onFilterBounds(src, ctm, dst);
 }
 
 bool SkImageFilter::onFilterImage(Proxy*, const SkBitmap&, const SkMatrix&,
                                   SkBitmap*, SkIPoint*) {
     return false;
 }
 
 bool SkImageFilter::canFilterImageGPU() const {
-    return this->asNewEffect(NULL, NULL);
+    return this->asNewEffect(NULL, NULL, SkIPoint::Make(0, 0));
 }
 
 bool SkImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, SkBitmap* result,
                                    SkIPoint* offset) {
 #if SK_SUPPORT_GPU
     SkBitmap input;
     SkASSERT(fInputCount == 1);
     if (!SkImageFilterUtils::GetInputResultGPU(this->getInput(0), proxy, src, &input, offset)) {
         return false;
     }
     GrTexture* srcTexture = input.getTexture();
-    SkRect rect;
-    src.getBounds(&rect);
+    SkIRect bounds;
+    src.getBounds(&bounds);
+    if (!this->applyCropRect(&bounds)) {
+        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 = input.width();
-    desc.fHeight = input.height();
+    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, rect);
+    GrContext::AutoClip acs(context, dstRect);
     GrEffectRef* effect;
-    this->asNewEffect(&effect, srcTexture);
+    this->asNewEffect(&effect, srcTexture, SkIPoint::Make(bounds.left(), bounds.top()));
     SkASSERT(effect);
     SkAutoUnref effectRef(effect);
     GrPaint paint;
     paint.addColorEffect(effect);
-    context->drawRect(paint, rect);
+    context->drawRectToRect(paint, dstRect, srcRect);
+
     SkAutoTUnref<GrTexture> resultTex(dst.detach());
-    SkImageFilterUtils::WrapTexture(resultTex, input.width(), input.height(), result);
+    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 {
     return rect->intersect(fCropRect);
 }
 
 bool SkImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
                                    SkIRect* dst) {
     *dst = src;
     return true;
 }
 
-bool SkImageFilter::asNewEffect(GrEffectRef**, GrTexture*) const {
+bool SkImageFilter::asNewEffect(GrEffectRef**, GrTexture*, const SkIPoint& offset) const {
     return false;
 }
 
 bool SkImageFilter::asColorFilter(SkColorFilter**) const {
     return false;
 }