Implement intra-frame cacheing in image filters.

src/effects/SkDropShadowImageFilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDropShadowImageFilter.h"
 
 #include "SkBitmap.h"
 #include "SkBlurImageFilter.h"
 #include "SkCanvas.h"
 #include "SkColorMatrixFilter.h"
 #include "SkDevice.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 
-SkDropShadowImageFilter::SkDropShadowImageFilter(SkScalar dx, SkScalar dy, SkScalar sigma, SkColor color, SkImageFilter* input)
+SkDropShadowImageFilter::SkDropShadowImageFilter(SkScalar dx, SkScalar dy, SkScalar sigma,
+                                                 SkColor color, SkImageFilter* input)
     : INHERITED(input)
     , fDx(dx)
     , fDy(dy)
     , fSigmaX(sigma)
     , fSigmaY(sigma)
     , fColor(color)
 {
 }
 
-SkDropShadowImageFilter::SkDropShadowImageFilter(SkScalar dx, SkScalar dy, SkScalar sigmaX, SkScalar sigmaY, SkColor color, SkImageFilter* input, const CropRect* cropRect)
+SkDropShadowImageFilter::SkDropShadowImageFilter(SkScalar dx, SkScalar dy,
+                                                 SkScalar sigmaX, SkScalar sigmaY, SkColor color,
+                                                 SkImageFilter* input, const CropRect* cropRect)
     : INHERITED(input, cropRect)
     , fDx(dx)
     , fDy(dy)
     , fSigmaX(sigmaX)
     , fSigmaY(sigmaY)
     , fColor(color)
 {
 }
 
 SkDropShadowImageFilter::SkDropShadowImageFilter(SkReadBuffer& buffer)
@@ skipping 12 matching lines @@
 void SkDropShadowImageFilter::flatten(SkWriteBuffer& buffer) const
 {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fDx);
     buffer.writeScalar(fDy);
     buffer.writeScalar(fSigmaX);
     buffer.writeScalar(fSigmaY);
     buffer.writeColor(fColor);
 }
 
-bool SkDropShadowImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source, const Context& ctx, SkBitmap* result, SkIPoint* offset) const
+bool SkDropShadowImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source,
+                                            const Context& ctx,
+                                            SkBitmap* result, SkIPoint* offset) const
 {
     SkBitmap src = source;
     SkIPoint srcOffset = SkIPoint::Make(0, 0);
     if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctx, &src, &srcOffset))
         return false;
 
     SkIRect bounds;
     if (!this->applyCropRect(ctx, src, srcOffset, &bounds)) {
         return false;
     }
 
     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
     if (NULL == device.get()) {
         return false;
     }
     SkCanvas canvas(device.get());
 
     SkVector sigma, localSigma = SkVector::Make(fSigmaX, fSigmaY);
     ctx.ctm().mapVectors(&sigma, &localSigma, 1);
     sigma.fX = SkMaxScalar(0, sigma.fX);
     sigma.fY = SkMaxScalar(0, sigma.fY);
     SkAutoTUnref<SkImageFilter> blurFilter(SkBlurImageFilter::Create(sigma.fX, sigma.fY));
-    SkAutoTUnref<SkColorFilter> colorFilter(SkColorFilter::CreateModeFilter(fColor, SkXfermode::kSrcIn_Mode));
+    SkAutoTUnref<SkColorFilter> colorFilter(
+        SkColorFilter::CreateModeFilter(fColor, SkXfermode::kSrcIn_Mode));
     SkPaint paint;
     paint.setImageFilter(blurFilter.get());
     paint.setColorFilter(colorFilter.get());
     paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
     SkVector offsetVec, localOffsetVec = SkVector::Make(fDx, fDy);
     ctx.ctm().mapVectors(&offsetVec, &localOffsetVec, 1);
     canvas.translate(SkIntToScalar(srcOffset.fX - bounds.fLeft),
                      SkIntToScalar(srcOffset.fY - bounds.fTop));
     canvas.drawBitmap(src, offsetVec.fX, offsetVec.fY, &paint);
     canvas.drawBitmap(src, 0, 0);
@@ skipping 28 matching lines @@
     bounds.offset(-SkScalarCeilToInt(offsetVec.x()),
                   -SkScalarCeilToInt(offsetVec.y()));
     SkVector sigma, localSigma = SkVector::Make(fSigmaX, fSigmaY);
     ctm.mapVectors(&sigma, &localSigma, 1);
     bounds.outset(SkScalarCeilToInt(SkScalarMul(sigma.x(), SkIntToScalar(3))),
                   SkScalarCeilToInt(SkScalarMul(sigma.y(), SkIntToScalar(3))));
     bounds.join(src);
     *dst = bounds;
     return true;
 }