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      1 /*
      2  * Copyright (C) 2006 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef Sk1DPathEffect_DEFINED
     18 #define Sk1DPathEffect_DEFINED
     19 
     20 #include "SkPathEffect.h"
     21 #include "SkPath.h"
     22 
     23 class SkPathMeasure;
     24 
     25 //  This class is not exported to java.
     26 class Sk1DPathEffect : public SkPathEffect {
     27 public:
     28     //  override from SkPathEffect
     29     virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width);
     30 
     31 protected:
     32     /** Called at the start of each contour, returns the initial offset
     33         into that contour.
     34     */
     35     virtual SkScalar begin(SkScalar contourLength) = 0;
     36     /** Called with the current distance along the path, with the current matrix
     37         for the point/tangent at the specified distance.
     38         Return the distance to travel for the next call. If return <= 0, then that
     39         contour is done.
     40     */
     41     virtual SkScalar next(SkPath* dst, SkScalar distance, SkPathMeasure&) = 0;
     42 
     43 private:
     44     typedef SkPathEffect INHERITED;
     45 };
     46 
     47 class SkPath1DPathEffect : public Sk1DPathEffect {
     48 public:
     49     enum Style {
     50         kTranslate_Style,   // translate the shape to each position
     51         kRotate_Style,      // rotate the shape about its center
     52         kMorph_Style,       // transform each point, and turn lines into curves
     53 
     54         kStyleCount
     55     };
     56 
     57     /** Dash by replicating the specified path.
     58         @param path The path to replicate (dash)
     59         @param advance The space between instances of path
     60         @param phase distance (mod advance) along path for its initial position
     61         @param style how to transform path at each point (based on the current
     62                      position and tangent)
     63     */
     64     SkPath1DPathEffect(const SkPath& path, SkScalar advance, SkScalar phase, Style);
     65 
     66     // override from SkPathEffect
     67     virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width);
     68 
     69 protected:
     70     SkPath1DPathEffect(SkFlattenableReadBuffer& buffer);
     71 
     72     // overrides from Sk1DPathEffect
     73     virtual SkScalar begin(SkScalar contourLength);
     74     virtual SkScalar next(SkPath* dst, SkScalar distance, SkPathMeasure&);
     75     // overrides from SkFlattenable
     76     virtual void flatten(SkFlattenableWriteBuffer& );
     77     virtual Factory getFactory() { return CreateProc; }
     78 
     79 private:
     80     SkPath      fPath;          // copied from constructor
     81     SkScalar    fAdvance;       // copied from constructor
     82     SkScalar    fInitialOffset; // computed from phase
     83     Style       fStyle;         // copied from constructor
     84 
     85     static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) {
     86         return SkNEW_ARGS(SkPath1DPathEffect, (buffer));
     87     }
     88 
     89     typedef Sk1DPathEffect INHERITED;
     90 };
     91 
     92 
     93 #endif
     94