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/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPathMeasure_DEFINED
#define SkPathMeasure_DEFINED
#include "../private/SkTDArray.h"
#include "SkPath.h"
struct SkConic;
class SK_API SkPathMeasure : SkNoncopyable {
public:
SkPathMeasure();
/** Initialize the pathmeasure with the specified path. The path must remain valid
for the lifetime of the measure object, or until setPath() is called with
a different path (or null), since the measure object keeps a pointer to the
path object (does not copy its data).
resScale controls the precision of the measure. values > 1 increase the
precision (and possible slow down the computation).
*/
SkPathMeasure(const SkPath& path, bool forceClosed, SkScalar resScale = 1);
~SkPathMeasure();
/** Reset the pathmeasure with the specified path. The path must remain valid
for the lifetime of the measure object, or until setPath() is called with
a different path (or null), since the measure object keeps a pointer to the
path object (does not copy its data).
*/
void setPath(const SkPath*, bool forceClosed);
/** Return the total length of the current contour, or 0 if no path
is associated (e.g. resetPath(null))
*/
SkScalar getLength();
/** Pins distance to 0 <= distance <= getLength(), and then computes
the corresponding position and tangent.
Returns false if there is no path, or a zero-length path was specified, in which case
position and tangent are unchanged.
*/
bool SK_WARN_UNUSED_RESULT getPosTan(SkScalar distance, SkPoint* position,
SkVector* tangent);
enum MatrixFlags {
kGetPosition_MatrixFlag = 0x01,
kGetTangent_MatrixFlag = 0x02,
kGetPosAndTan_MatrixFlag = kGetPosition_MatrixFlag | kGetTangent_MatrixFlag
};
/** Pins distance to 0 <= distance <= getLength(), and then computes
the corresponding matrix (by calling getPosTan).
Returns false if there is no path, or a zero-length path was specified, in which case
matrix is unchanged.
*/
bool SK_WARN_UNUSED_RESULT getMatrix(SkScalar distance, SkMatrix* matrix,
MatrixFlags flags = kGetPosAndTan_MatrixFlag);
/** Given a start and stop distance, return in dst the intervening segment(s).
If the segment is zero-length, return false, else return true.
startD and stopD are pinned to legal values (0..getLength()). If startD > stopD
then return false (and leave dst untouched).
Begin the segment with a moveTo if startWithMoveTo is true
*/
bool getSegment(SkScalar startD, SkScalar stopD, SkPath* dst, bool startWithMoveTo);
/** Return true if the current contour is closed()
*/
bool isClosed();
/** Move to the next contour in the path. Return true if one exists, or false if
we're done with the path.
*/
bool nextContour();
#ifdef SK_DEBUG
void dump();
#endif
private:
SkPath::Iter fIter;
const SkPath* fPath;
SkScalar fTolerance;
SkScalar fLength; // relative to the current contour
int fFirstPtIndex; // relative to the current contour
bool fIsClosed; // relative to the current contour
bool fForceClosed;
struct Segment {
SkScalar fDistance; // total distance up to this point
unsigned fPtIndex; // index into the fPts array
unsigned fTValue : 30;
unsigned fType : 2;
SkScalar getScalarT() const;
};
SkTDArray<Segment> fSegments;
SkTDArray<SkPoint> fPts; // Points used to define the segments
static const Segment* NextSegment(const Segment*);
void buildSegments();
SkScalar compute_quad_segs(const SkPoint pts[3], SkScalar distance,
int mint, int maxt, int ptIndex);
SkScalar compute_conic_segs(const SkConic&, SkScalar distance,
int mint, const SkPoint& minPt,
int maxt, const SkPoint& maxPt, int ptIndex);
SkScalar compute_cubic_segs(const SkPoint pts[3], SkScalar distance,
int mint, int maxt, int ptIndex);
const Segment* distanceToSegment(SkScalar distance, SkScalar* t);
bool quad_too_curvy(const SkPoint pts[3]);
bool conic_too_curvy(const SkPoint& firstPt, const SkPoint& midTPt,const SkPoint& lastPt);
bool cheap_dist_exceeds_limit(const SkPoint& pt, SkScalar x, SkScalar y);
bool cubic_too_curvy(const SkPoint pts[4]);
};
#endif
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