d028056712
git-svn-id: http://skia.googlecode.com/svn/trunk@9054 2bbb7eff-a529-9590-31e7-b0007b416f81
110 lines
4.0 KiB
C++
110 lines
4.0 KiB
C++
/*
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* Copyright 2006 The Android Open Source Project
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkPathMeasure_DEFINED
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#define SkPathMeasure_DEFINED
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#include "SkPath.h"
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#include "SkTDArray.h"
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class SK_API SkPathMeasure : SkNoncopyable {
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public:
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SkPathMeasure();
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/** Initialize the pathmeasure with the specified path. The path must remain valid
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for the lifetime of the measure object, or until setPath() is called with
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a different path (or null), since the measure object keeps a pointer to the
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path object (does not copy its data).
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*/
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SkPathMeasure(const SkPath& path, bool forceClosed);
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~SkPathMeasure();
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/** Reset the pathmeasure with the specified path. The path must remain valid
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for the lifetime of the measure object, or until setPath() is called with
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a different path (or null), since the measure object keeps a pointer to the
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path object (does not copy its data).
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*/
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void setPath(const SkPath*, bool forceClosed);
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/** Return the total length of the current contour, or 0 if no path
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is associated (e.g. resetPath(null))
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*/
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SkScalar getLength();
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/** Pins distance to 0 <= distance <= getLength(), and then computes
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the corresponding position and tangent.
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Returns false if there is no path, or a zero-length path was specified, in which case
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position and tangent are unchanged.
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*/
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bool SK_WARN_UNUSED_RESULT getPosTan(SkScalar distance, SkPoint* position,
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SkVector* tangent);
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enum MatrixFlags {
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kGetPosition_MatrixFlag = 0x01,
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kGetTangent_MatrixFlag = 0x02,
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kGetPosAndTan_MatrixFlag = kGetPosition_MatrixFlag | kGetTangent_MatrixFlag
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};
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/** Pins distance to 0 <= distance <= getLength(), and then computes
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the corresponding matrix (by calling getPosTan).
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Returns false if there is no path, or a zero-length path was specified, in which case
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matrix is unchanged.
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*/
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bool SK_WARN_UNUSED_RESULT getMatrix(SkScalar distance, SkMatrix* matrix,
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MatrixFlags flags = kGetPosAndTan_MatrixFlag);
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/** Given a start and stop distance, return in dst the intervening segment(s).
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If the segment is zero-length, return false, else return true.
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startD and stopD are pinned to legal values (0..getLength()). If startD <= stopD
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then return false (and leave dst untouched).
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Begin the segment with a moveTo if startWithMoveTo is true
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*/
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bool getSegment(SkScalar startD, SkScalar stopD, SkPath* dst, bool startWithMoveTo);
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/** Return true if the current contour is closed()
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*/
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bool isClosed();
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/** Move to the next contour in the path. Return true if one exists, or false if
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we're done with the path.
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*/
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bool nextContour();
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#ifdef SK_DEBUG
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void dump();
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#endif
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private:
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SkPath::Iter fIter;
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const SkPath* fPath;
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SkScalar fLength; // relative to the current contour
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int fFirstPtIndex; // relative to the current contour
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bool fIsClosed; // relative to the current contour
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bool fForceClosed;
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struct Segment {
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SkScalar fDistance; // total distance up to this point
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unsigned fPtIndex : 15; // index into the fPts array
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unsigned fTValue : 15;
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unsigned fType : 2;
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SkScalar getScalarT() const;
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};
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SkTDArray<Segment> fSegments;
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SkTDArray<SkPoint> fPts; // Points used to define the segments
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static const Segment* NextSegment(const Segment*);
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void buildSegments();
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SkScalar compute_quad_segs(const SkPoint pts[3], SkScalar distance,
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int mint, int maxt, int ptIndex);
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SkScalar compute_cubic_segs(const SkPoint pts[3], SkScalar distance,
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int mint, int maxt, int ptIndex);
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const Segment* distanceToSegment(SkScalar distance, SkScalar* t);
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};
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#endif
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