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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 SkDashPathEffect_DEFINED
      9 #define SkDashPathEffect_DEFINED
     10 
     11 #include "SkPathEffect.h"
     12 
     13 /** \class SkDashPathEffect
     14 
     15     SkDashPathEffect is a subclass of SkPathEffect that implements dashing
     16 */
     17 class SK_API SkDashPathEffect : public SkPathEffect {
     18 public:
     19     /** intervals: array containing an even number of entries (>=2), with
     20          the even indices specifying the length of "on" intervals, and the odd
     21          indices specifying the length of "off" intervals.
     22         count: number of elements in the intervals array
     23         phase: offset into the intervals array (mod the sum of all of the
     24          intervals).
     25 
     26         For example: if intervals[] = {10, 20}, count = 2, and phase = 25,
     27          this will set up a dashed path like so:
     28          5 pixels off
     29          10 pixels on
     30          20 pixels off
     31          10 pixels on
     32          20 pixels off
     33          ...
     34         A phase of -5, 25, 55, 85, etc. would all result in the same path,
     35          because the sum of all the intervals is 30.
     36 
     37         Note: only affects stroked paths.
     38     */
     39     SkDashPathEffect(const SkScalar intervals[], int count, SkScalar phase,
     40                      bool scaleToFit = false);
     41     virtual ~SkDashPathEffect();
     42 
     43     virtual bool filterPath(SkPath* dst, const SkPath& src,
     44                             SkStrokeRec*, const SkRect*) const SK_OVERRIDE;
     45 
     46     virtual bool asPoints(PointData* results, const SkPath& src,
     47                           const SkStrokeRec&, const SkMatrix&,
     48                           const SkRect*) const SK_OVERRIDE;
     49 
     50     virtual Factory getFactory() SK_OVERRIDE;
     51 
     52     static SkFlattenable* CreateProc(SkFlattenableReadBuffer&);
     53 
     54 protected:
     55     SkDashPathEffect(SkFlattenableReadBuffer&);
     56     virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
     57 
     58 private:
     59     SkScalar*   fIntervals;
     60     int32_t     fCount;
     61     // computed from phase
     62     SkScalar    fInitialDashLength;
     63     int32_t     fInitialDashIndex;
     64     SkScalar    fIntervalLength;
     65     bool        fScaleToFit;
     66 
     67     typedef SkPathEffect INHERITED;
     68 };
     69 
     70 #endif
     71