Home | History | Annotate | Download | only in core 
      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 SkPathMeasure_DEFINED
      9 #define SkPathMeasure_DEFINED
     10 
     11 #include "../private/SkNoncopyable.h"
     12 #include "../private/SkTDArray.h"
     13 #include "SkContourMeasure.h"
     14 #include "SkPath.h"
     15 
     16 class SK_API SkPathMeasure : SkNoncopyable {
     17 public:
     18     SkPathMeasure();
     19     /** Initialize the pathmeasure with the specified path. The parts of the path that are needed
     20      *  are copied, so the client is free to modify/delete the path after this call.
     21      *
     22      *  resScale controls the precision of the measure. values > 1 increase the
     23      *  precision (and possible slow down the computation).
     24      */
     25     SkPathMeasure(const SkPath& path, bool forceClosed, SkScalar resScale = 1);
     26     ~SkPathMeasure();
     27 
     28     /** Reset the pathmeasure with the specified path. The parts of the path that are needed
     29      *  are copied, so the client is free to modify/delete the path after this call..
     30      */
     31     void setPath(const SkPath*, bool forceClosed);
     32 
     33     /** Return the total length of the current contour, or 0 if no path
     34         is associated (e.g. resetPath(null))
     35     */
     36     SkScalar getLength();
     37 
     38     /** Pins distance to 0 <= distance <= getLength(), and then computes
     39         the corresponding position and tangent.
     40         Returns false if there is no path, or a zero-length path was specified, in which case
     41         position and tangent are unchanged.
     42     */
     43     bool SK_WARN_UNUSED_RESULT getPosTan(SkScalar distance, SkPoint* position,
     44                                          SkVector* tangent);
     45 
     46     enum MatrixFlags {
     47         kGetPosition_MatrixFlag     = 0x01,
     48         kGetTangent_MatrixFlag      = 0x02,
     49         kGetPosAndTan_MatrixFlag    = kGetPosition_MatrixFlag | kGetTangent_MatrixFlag
     50     };
     51 
     52     /** Pins distance to 0 <= distance <= getLength(), and then computes
     53         the corresponding matrix (by calling getPosTan).
     54         Returns false if there is no path, or a zero-length path was specified, in which case
     55         matrix is unchanged.
     56     */
     57     bool SK_WARN_UNUSED_RESULT getMatrix(SkScalar distance, SkMatrix* matrix,
     58                                   MatrixFlags flags = kGetPosAndTan_MatrixFlag);
     59 
     60     /** Given a start and stop distance, return in dst the intervening segment(s).
     61         If the segment is zero-length, return false, else return true.
     62         startD and stopD are pinned to legal values (0..getLength()). If startD > stopD
     63         then return false (and leave dst untouched).
     64         Begin the segment with a moveTo if startWithMoveTo is true
     65     */
     66     bool getSegment(SkScalar startD, SkScalar stopD, SkPath* dst, bool startWithMoveTo);
     67 
     68     /** Return true if the current contour is closed()
     69     */
     70     bool isClosed();
     71 
     72     /** Move to the next contour in the path. Return true if one exists, or false if
     73         we're done with the path.
     74     */
     75     bool nextContour();
     76 
     77 #ifdef SK_DEBUG
     78     void    dump();
     79 #endif
     80 
     81 private:
     82     SkContourMeasureIter    fIter;
     83     sk_sp<SkContourMeasure> fContour;
     84 };
     85 
     86 #endif
     87