add asAShadowBlur for android to drawlooper

include/core/SkMaskFilter.h

 
 /*
  * Copyright 2006 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.
  */
 
 
 #ifndef SkMaskFilter_DEFINED
 #define SkMaskFilter_DEFINED
 
+#include "SkBlurTypes.h"
 #include "SkFlattenable.h"
 #include "SkMask.h"
 #include "SkPaint.h"
 
 class GrContext;
 class GrPaint;
 class SkBitmap;
 class SkBlitter;
 class SkBounder;
 class SkMatrix;
@@ skipping 108 matching lines @@
      * paint as its src param and the filter adjust those bounds using its
      * current mask and returns the result using the dest param. Callers are
      * allowed to provide the same struct for both src and dest so each
      * implementation must accomodate that behavior.
      *
      *  The default impl calls filterMask with the src mask having no image,
      *  but subclasses may override this if they can compute the rect faster.
      */
     virtual void computeFastBounds(const SkRect& src, SkRect* dest) const;
 
+    struct BlurRec {
+        SkScalar        fSigma;
+        SkBlurStyle     fStyle;
+        SkBlurQuality   fQuality;
+    };
+    /**
+     *  If this filter can be represented by a BlurRec, return true and (if not null) fill in the
+     *  provided BlurRec parameter. If this effect cannot be represented as a BlurRec, return false
+     *  and ignore the BlurRec parameter.
+     */
+    virtual bool asABlur(BlurRec*) const;
+
     SK_TO_STRING_PUREVIRT()
     SK_DEFINE_FLATTENABLE_TYPE(SkMaskFilter)
 
 protected:
     SkMaskFilter() {}
     // empty for now, but lets get our subclass to remember to init us for the future
     SkMaskFilter(SkReadBuffer& buffer) : INHERITED(buffer) {}
 
     enum FilterReturn {
         kFalse_FilterReturn,
@@ skipping 50 matching lines @@
      to render that mask. Returns false if filterMask() returned false.
      */
     bool filterRRect(const SkRRect& devRRect, const SkMatrix& devMatrix,
                      const SkRasterClip&, SkBounder*, SkBlitter* blitter,
                      SkPaint::Style style) const;
 
     typedef SkFlattenable INHERITED;
 };
 
 #endif