Implement support for a Context parameter in image filters

src/effects/SkAlphaThresholdFilter.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 "SkAlphaThresholdFilter.h"
 #include "SkBitmap.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkRegion.h"
 
 class SK_API SkAlphaThresholdFilterImpl : public SkImageFilter {
 public:
     SkAlphaThresholdFilterImpl(const SkRegion& region, SkScalar innerThreshold, SkScalar outerThreshold);
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkAlphaThresholdFilterImpl)
 
 protected:
     explicit SkAlphaThresholdFilterImpl(SkReadBuffer& buffer);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
-    virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
+    virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
                                SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
 #if SK_SUPPORT_GPU
     virtual bool asNewEffect(GrEffectRef** effect, GrTexture* texture,
                              const SkMatrix& matrix, const SkIRect& bounds) const SK_OVERRIDE;
 #endif
 
 private:
     SkRegion fRegion;
     SkScalar fInnerThreshold;
     SkScalar fOuterThreshold;
@@ skipping 262 matching lines @@
 #endif
 
 void SkAlphaThresholdFilterImpl::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fInnerThreshold);
     buffer.writeScalar(fOuterThreshold);
     buffer.writeRegion(fRegion);
 }
 
 bool SkAlphaThresholdFilterImpl::onFilterImage(Proxy*, const SkBitmap& src,
-                                               const SkMatrix& matrix, SkBitmap* dst,
+                                               const Context& ctx, SkBitmap* dst,
                                                SkIPoint* offset) const {
     SkASSERT(src.colorType() == kPMColor_SkColorType);
 
     if (src.colorType() != kPMColor_SkColorType) {
         return false;
     }
 
     SkMatrix localInverse;
-    if (!matrix.invert(&localInverse)) {
+    if (!ctx.ctm().invert(&localInverse)) {
         return false;
     }
 
     SkAutoLockPixels alp(src);
     SkASSERT(src.getPixels());
     if (!src.getPixels() || src.width() <= 0 || src.height() <= 0) {
         return false;
     }
 
     dst->setConfig(src.config(), src.width(), src.height());
@@ skipping 31 matching lines @@
                                                   (U8CPU)(SkColorGetG(source) * scale),
                                                   (U8CPU)(SkColorGetB(source) * scale));
                 }
             }
             dptr[y * dst->width() + x] = output_color;
         }
     }
 
     return true;
 }