In image filters, apply the CTM and offset to the crop rect. This is necessary to compensate for bo…

include/core/SkImageFilter.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageFilter_DEFINED
 #define SkImageFilter_DEFINED
 
@@ skipping 59 matching lines @@
     /**
      *  Returns true if the filter can be expressed a single-pass
      *  GrEffect, used to process this filter on the GPU, or false if
      *  not.
      *
      *  If effect is non-NULL, a new GrEffect instance is stored
      *  in it.  The caller assumes ownership of the stage, and it is up to the
      *  caller to unref it.
      *
      *  The effect can assume its vertexCoords space maps 1-to-1 with texels
-     *  in the texture.  "offset" is the delta between the source and
-     *  destination rect's origins, when cropped processing is being performed.
+     *  in the texture.  "matrix" is a transformation to apply to filter
+     *  parameters before they are used in the effect. Note that this function
+     *  will be called with (NULL, NULL, SkMatrix::I()) to query for support,
+     *  so returning "true" indicates support for all possible matrices.
      */
-    virtual bool asNewEffect(GrEffectRef** effect, GrTexture*, const SkIPoint& offset) const;
+    virtual bool asNewEffect(GrEffectRef** effect, GrTexture*, const SkMatrix& matrix) const;
 
     /**
      *  Returns true if the filter can be processed on the GPU.  This is most
      *  often used for multi-pass effects, where intermediate results must be
      *  rendered to textures.  For single-pass effects, use asNewEffect().
-     *  The default implementation returns asNewEffect(NULL, NULL).
+     *  The default implementation returns asNewEffect(NULL, NULL, SkMatrix::I()).
      */
     virtual bool canFilterImageGPU() const;
 
     /**
      *  Process this image filter on the GPU.  This is most often used for
      *  multi-pass effects, where intermediate results must be rendered to
      *  textures.  For single-pass effects, use asNewEffect().  src is the
      *  source image for processing, as a texture-backed bitmap.  result is
      *  the destination bitmap, which should contain a texture-backed pixelref
      *  on success.  offset is the amount to translate the resulting image
@@ skipping 52 matching lines @@
     explicit SkImageFilter(SkFlattenableReadBuffer& rb);
 
     virtual void flatten(SkFlattenableWriteBuffer& wb) const SK_OVERRIDE;
 
     // Default impl returns false
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
                                SkBitmap* result, SkIPoint* offset);
     // Default impl copies src into dst and returns true
     virtual bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*);
 
-    // Sets rect to the intersection of rect and the crop rect. If there
-    // is no overlap, returns false and leaves rect unchanged.
-    bool applyCropRect(SkIRect* rect) const;
+    // Applies "matrix" to the crop rect, and sets "rect" to the intersection of
+    // "rect" and the transformed crop rect. If there is no overlap, returns
+    // false and leaves "rect" unchanged.
+    bool applyCropRect(SkIRect* rect, const SkMatrix& matrix) const;
 
 private:
     typedef SkFlattenable INHERITED;
     int fInputCount;
     SkImageFilter** fInputs;
     SkIRect fCropRect;
 };
 
 #endif