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      1 /*
      2  * Copyright 2006 The Android Open Source Project
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #ifndef SkDiscretePathEffect_DEFINED
      9 #define SkDiscretePathEffect_DEFINED
     10 
     11 #include "SkPathEffect.h"
     12 
     13 /** \class SkDiscretePathEffect
     14 
     15     This path effect chops a path into discrete segments, and randomly displaces them.
     16 */
     17 class SK_API SkDiscretePathEffect : public SkPathEffect {
     18 public:
     19     /** Break the path into segments of segLength length, and randomly move the endpoints
     20         away from the original path by a maximum of deviation.
     21         Note: works on filled or framed paths
     22 
     23         @param seedAssist This is a caller-supplied seedAssist that modifies
     24                           the seed value that is used to randomize the path
     25                           segments' endpoints. If not supplied it defaults to 0,
     26                           in which case filtering a path multiple times will
     27                           result in the same set of segments (this is useful for
     28                           testing). If a caller does not want this behaviour
     29                           they can pass in a different seedAssist to get a
     30                           different set of path segments.
     31     */
     32     static sk_sp<SkPathEffect> Make(SkScalar segLength, SkScalar dev, uint32_t seedAssist = 0);
     33 
     34     virtual bool filterPath(SkPath* dst, const SkPath& src,
     35                             SkStrokeRec*, const SkRect*) const override;
     36 
     37     SK_TO_STRING_OVERRIDE()
     38     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDiscretePathEffect)
     39 
     40 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
     41     bool exposedInAndroidJavaAPI() const override { return true; }
     42 #endif
     43 
     44 protected:
     45     SkDiscretePathEffect(SkScalar segLength,
     46                          SkScalar deviation,
     47                          uint32_t seedAssist);
     48     void flatten(SkWriteBuffer&) const override;
     49 
     50 private:
     51     SkScalar fSegLength, fPerterb;
     52 
     53     /* Caller-supplied 32 bit seed assist */
     54     uint32_t fSeedAssist;
     55 
     56     typedef SkPathEffect INHERITED;
     57 };
     58 
     59 #endif
     60