michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkPathMeasure_DEFINED
michael@0: #define SkPathMeasure_DEFINED
michael@0: 
michael@0: #include "SkPath.h"
michael@0: #include "SkTDArray.h"
michael@0: 
michael@0: class SK_API SkPathMeasure : SkNoncopyable {
michael@0: public:
michael@0:     SkPathMeasure();
michael@0:     /** Initialize the pathmeasure with the specified path. The path must remain valid
michael@0:         for the lifetime of the measure object, or until setPath() is called with
michael@0:         a different path (or null), since the measure object keeps a pointer to the
michael@0:         path object (does not copy its data).
michael@0:     */
michael@0:     SkPathMeasure(const SkPath& path, bool forceClosed);
michael@0:     ~SkPathMeasure();
michael@0: 
michael@0:     /** Reset the pathmeasure with the specified path. The path must remain valid
michael@0:         for the lifetime of the measure object, or until setPath() is called with
michael@0:         a different path (or null), since the measure object keeps a pointer to the
michael@0:         path object (does not copy its data).
michael@0:     */
michael@0:     void setPath(const SkPath*, bool forceClosed);
michael@0: 
michael@0:     /** Return the total length of the current contour, or 0 if no path
michael@0:         is associated (e.g. resetPath(null))
michael@0:     */
michael@0:     SkScalar getLength();
michael@0: 
michael@0:     /** Pins distance to 0 <= distance <= getLength(), and then computes
michael@0:         the corresponding position and tangent.
michael@0:         Returns false if there is no path, or a zero-length path was specified, in which case
michael@0:         position and tangent are unchanged.
michael@0:     */
michael@0:     bool SK_WARN_UNUSED_RESULT getPosTan(SkScalar distance, SkPoint* position,
michael@0:                                          SkVector* tangent);
michael@0: 
michael@0:     enum MatrixFlags {
michael@0:         kGetPosition_MatrixFlag     = 0x01,
michael@0:         kGetTangent_MatrixFlag      = 0x02,
michael@0:         kGetPosAndTan_MatrixFlag    = kGetPosition_MatrixFlag | kGetTangent_MatrixFlag
michael@0:     };
michael@0: 
michael@0:     /** Pins distance to 0 <= distance <= getLength(), and then computes
michael@0:         the corresponding matrix (by calling getPosTan).
michael@0:         Returns false if there is no path, or a zero-length path was specified, in which case
michael@0:         matrix is unchanged.
michael@0:     */
michael@0:     bool SK_WARN_UNUSED_RESULT getMatrix(SkScalar distance, SkMatrix* matrix,
michael@0:                                   MatrixFlags flags = kGetPosAndTan_MatrixFlag);
michael@0: 
michael@0:     /** Given a start and stop distance, return in dst the intervening segment(s).
michael@0:         If the segment is zero-length, return false, else return true.
michael@0:         startD and stopD are pinned to legal values (0..getLength()). If startD <= stopD
michael@0:         then return false (and leave dst untouched).
michael@0:         Begin the segment with a moveTo if startWithMoveTo is true
michael@0:     */
michael@0:     bool getSegment(SkScalar startD, SkScalar stopD, SkPath* dst, bool startWithMoveTo);
michael@0: 
michael@0:     /** Return true if the current contour is closed()
michael@0:     */
michael@0:     bool isClosed();
michael@0: 
michael@0:     /** Move to the next contour in the path. Return true if one exists, or false if
michael@0:         we're done with the path.
michael@0:     */
michael@0:     bool nextContour();
michael@0: 
michael@0: #ifdef SK_DEBUG
michael@0:     void    dump();
michael@0: #endif
michael@0: 
michael@0: private:
michael@0:     SkPath::Iter    fIter;
michael@0:     const SkPath*   fPath;
michael@0:     SkScalar        fLength;            // relative to the current contour
michael@0:     int             fFirstPtIndex;      // relative to the current contour
michael@0:     bool            fIsClosed;          // relative to the current contour
michael@0:     bool            fForceClosed;
michael@0: 
michael@0:     struct Segment {
michael@0:         SkScalar    fDistance;  // total distance up to this point
michael@0:         unsigned    fPtIndex : 15; // index into the fPts array
michael@0:         unsigned    fTValue : 15;
michael@0:         unsigned    fType : 2;
michael@0: 
michael@0:         SkScalar getScalarT() const;
michael@0:     };
michael@0:     SkTDArray<Segment>  fSegments;
michael@0:     SkTDArray<SkPoint>  fPts; // Points used to define the segments
michael@0: 
michael@0:     static const Segment* NextSegment(const Segment*);
michael@0: 
michael@0:     void     buildSegments();
michael@0:     SkScalar compute_quad_segs(const SkPoint pts[3], SkScalar distance,
michael@0:                                 int mint, int maxt, int ptIndex);
michael@0:     SkScalar compute_cubic_segs(const SkPoint pts[3], SkScalar distance,
michael@0:                                 int mint, int maxt, int ptIndex);
michael@0:     const Segment* distanceToSegment(SkScalar distance, SkScalar* t);
michael@0: };
michael@0: 
michael@0: #endif