Implement crop rect for SkImageFilter

src/effects/SkBlurImageFilter.cpp

 /*
  * Copyright 2011 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 "SkBitmap.h"
 #include "SkBlurImageFilter.h"
 #include "SkColorPriv.h"
 #include "SkFlattenableBuffers.h"
 #include "SkGpuBlurUtils.h"
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "SkImageFilterUtils.h"
 #endif
 
 SkBlurImageFilter::SkBlurImageFilter(SkFlattenableReadBuffer& buffer)
   : INHERITED(buffer) {
     fSigma.fWidth = buffer.readScalar();
     fSigma.fHeight = buffer.readScalar();
 }
 
-SkBlurImageFilter::SkBlurImageFilter(SkScalar sigmaX, SkScalar sigmaY, SkImageFilter* input)
-    : INHERITED(input), fSigma(SkSize::Make(sigmaX, sigmaY)) {
+SkBlurImageFilter::SkBlurImageFilter(SkScalar sigmaX,
+                                     SkScalar sigmaY,
+                                     SkImageFilter* input,
+                                     const SkIRect* cropRect)
+    : INHERITED(input, cropRect), fSigma(SkSize::Make(sigmaX, sigmaY)) {
     SkASSERT(sigmaX >= 0 && sigmaY >= 0);
 }
 
 void SkBlurImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fSigma.fWidth);
     buffer.writeScalar(fSigma.fHeight);
 }
 
 static void boxBlurX(const SkBitmap& src, SkBitmap* dst, int kernelSize,
-                     int leftOffset, int rightOffset)
+                     int leftOffset, int rightOffset, const SkIRect& bounds)
 {
-    int width = src.width(), height = src.height();
+    int width = bounds.width(), height = bounds.height();
     int rightBorder = SkMin32(rightOffset + 1, width);
     for (int y = 0; y < height; ++y) {
         int sumA = 0, sumR = 0, sumG = 0, sumB = 0;
-        SkPMColor* p = src.getAddr32(0, y);
+        SkPMColor* p = src.getAddr32(bounds.fLeft, y + bounds.fTop);
         for (int i = 0; i < rightBorder; ++i) {
             sumA += SkGetPackedA32(*p);
             sumR += SkGetPackedR32(*p);
             sumG += SkGetPackedG32(*p);
             sumB += SkGetPackedB32(*p);
             p++;
         }
 
-        const SkColor* sptr = src.getAddr32(0, y);
+        const SkColor* sptr = src.getAddr32(bounds.fLeft, bounds.fTop + y);
         SkColor* dptr = dst->getAddr32(0, y);
         for (int x = 0; x < width; ++x) {
             *dptr = SkPackARGB32(sumA / kernelSize,
                                  sumR / kernelSize,
                                  sumG / kernelSize,
                                  sumB / kernelSize);
             if (x >= leftOffset) {
                 SkColor l = *(sptr - leftOffset);
                 sumA -= SkGetPackedA32(l);
                 sumR -= SkGetPackedR32(l);
                 sumG -= SkGetPackedG32(l);
                 sumB -= SkGetPackedB32(l);
             }
             if (x + rightOffset + 1 < width) {
                 SkColor r = *(sptr + rightOffset + 1);
                 sumA += SkGetPackedA32(r);
                 sumR += SkGetPackedR32(r);
                 sumG += SkGetPackedG32(r);
                 sumB += SkGetPackedB32(r);
             }
             sptr++;
             dptr++;
         }
     }
 }
 
 static void boxBlurY(const SkBitmap& src, SkBitmap* dst, int kernelSize,
-                     int topOffset, int bottomOffset)
+                     int topOffset, int bottomOffset, const SkIRect& bounds)
 {
-    int width = src.width(), height = src.height();
+    int width = bounds.width(), height = bounds.height();
     int bottomBorder = SkMin32(bottomOffset + 1, height);
     int srcStride = src.rowBytesAsPixels();
     int dstStride = dst->rowBytesAsPixels();
     for (int x = 0; x < width; ++x) {
         int sumA = 0, sumR = 0, sumG = 0, sumB = 0;
-        SkColor* p = src.getAddr32(x, 0);
+        SkColor* p = src.getAddr32(bounds.fLeft + x, bounds.fTop);
         for (int i = 0; i < bottomBorder; ++i) {
             sumA += SkGetPackedA32(*p);
             sumR += SkGetPackedR32(*p);
             sumG += SkGetPackedG32(*p);
             sumB += SkGetPackedB32(*p);
             p += srcStride;
         }
 
-        const SkColor* sptr = src.getAddr32(x, 0);
+        const SkColor* sptr = src.getAddr32(bounds.fLeft + x, bounds.fTop);
         SkColor* dptr = dst->getAddr32(x, 0);
         for (int y = 0; y < height; ++y) {
             *dptr = SkPackARGB32(sumA / kernelSize,
                                  sumR / kernelSize,
                                  sumG / kernelSize,
                                  sumB / kernelSize);
             if (y >= topOffset) {
                 SkColor l = *(sptr - topOffset * srcStride);
                 sumA -= SkGetPackedA32(l);
                 sumR -= SkGetPackedR32(l);
@@ skipping 39 matching lines @@
 
     if (src.config() != SkBitmap::kARGB_8888_Config) {
         return false;
     }
 
     SkAutoLockPixels alp(src);
     if (!src.getPixels()) {
         return false;
     }
 
-    dst->setConfig(src.config(), src.width(), src.height());
+    SkIRect srcBounds, dstBounds;
+    src.getBounds(&srcBounds);
+    if (!this->applyCropRect(&srcBounds)) {
+        return false;
+    }
+
+    dst->setConfig(src.config(), srcBounds.width(), srcBounds.height());
+    dst->getBounds(&dstBounds);
     dst->allocPixels();
     int kernelSizeX, kernelSizeX3, lowOffsetX, highOffsetX;
     int kernelSizeY, kernelSizeY3, lowOffsetY, highOffsetY;
     getBox3Params(fSigma.width(), &kernelSizeX, &kernelSizeX3, &lowOffsetX, &highOffsetX);
     getBox3Params(fSigma.height(), &kernelSizeY, &kernelSizeY3, &lowOffsetY, &highOffsetY);
 
     if (kernelSizeX < 0 || kernelSizeY < 0) {
         return false;
     }
 
     if (kernelSizeX == 0 && kernelSizeY == 0) {
         src.copyTo(dst, dst->config());
         return true;
     }
 
     SkBitmap temp;
     temp.setConfig(dst->config(), dst->width(), dst->height());
     if (!temp.allocPixels()) {
         return false;
     }
 
     if (kernelSizeX > 0 && kernelSizeY > 0) {
-        boxBlurX(src,  &temp, kernelSizeX,  lowOffsetX, highOffsetX);
-        boxBlurY(temp, dst,   kernelSizeY,  lowOffsetY, highOffsetY);
-        boxBlurX(*dst, &temp, kernelSizeX,  highOffsetX,  lowOffsetX);
-        boxBlurY(temp, dst,   kernelSizeY,  highOffsetY,  lowOffsetY);
-        boxBlurX(*dst, &temp, kernelSizeX3, highOffsetX, highOffsetX);
-        boxBlurY(temp, dst,   kernelSizeY3, highOffsetY, highOffsetY);
+        boxBlurX(src,  &temp, kernelSizeX,  lowOffsetX,  highOffsetX, srcBounds);
+        boxBlurY(temp, dst,   kernelSizeY,  lowOffsetY,  highOffsetY, dstBounds);
+        boxBlurX(*dst, &temp, kernelSizeX,  highOffsetX, lowOffsetX, dstBounds);
+        boxBlurY(temp, dst,   kernelSizeY,  highOffsetY, lowOffsetY, dstBounds);
+        boxBlurX(*dst, &temp, kernelSizeX3, highOffsetX, highOffsetX, dstBounds);
+        boxBlurY(temp, dst,   kernelSizeY3, highOffsetY, highOffsetY, dstBounds);
     } else if (kernelSizeX > 0) {
-        boxBlurX(src,  dst,   kernelSizeX,  lowOffsetX, highOffsetX);
-        boxBlurX(*dst, &temp, kernelSizeX,  highOffsetX,  lowOffsetX);
-        boxBlurX(temp, dst,   kernelSizeX3, highOffsetX, highOffsetX);
+        boxBlurX(src,  dst,   kernelSizeX,  lowOffsetX,  highOffsetX, srcBounds);
+        boxBlurX(*dst, &temp, kernelSizeX,  highOffsetX, lowOffsetX, dstBounds);
+        boxBlurX(temp, dst,   kernelSizeX3, highOffsetX, highOffsetX, dstBounds);
     } else if (kernelSizeY > 0) {
-        boxBlurY(src,  dst,   kernelSizeY,  lowOffsetY, highOffsetY);
-        boxBlurY(*dst, &temp, kernelSizeY,  highOffsetY, lowOffsetY);
-        boxBlurY(temp, dst,   kernelSizeY3, highOffsetY, highOffsetY);
+        boxBlurY(src,  dst,   kernelSizeY,  lowOffsetY,  highOffsetY, srcBounds);
+        boxBlurY(*dst, &temp, kernelSizeY,  highOffsetY, lowOffsetY, dstBounds);
+        boxBlurY(temp, dst,   kernelSizeY3, highOffsetY, highOffsetY, dstBounds);
     }
+    offset->fX += srcBounds.fLeft;
+    offset->fY += srcBounds.fTop;
     return true;
 }
 
 bool SkBlurImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, SkBitmap* result,
                                        SkIPoint* offset) {
 #if SK_SUPPORT_GPU
     SkBitmap input;
     if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, &input, offset)) {
         return false;
     }
     GrTexture* source = input.getTexture();
-    SkRect rect;
+    SkIRect rect;
     src.getBounds(&rect);
+    if (!this->applyCropRect(&rect)) {
+        return false;
+    }
     SkAutoTUnref<GrTexture> tex(SkGpuBlurUtils::GaussianBlur(source->getContext(),
-                                                             source, false, rect,
-                                                             fSigma.width(), fSigma.height()));
-    return SkImageFilterUtils::WrapTexture(tex, src.width(), src.height(), result);
+                                                             source,
+                                                             false,
+                                                             SkRect::Make(rect),
+                                                             true,
+                                                             fSigma.width(),
+                                                             fSigma.height()));
+    offset->fX += rect.fLeft;
+    offset->fY += rect.fTop;
+    return SkImageFilterUtils::WrapTexture(tex, rect.width(), rect.height(), result);
 #else
     SkDEBUGFAIL("Should not call in GPU-less build");
     return false;
 #endif
 }