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+/* include/graphics/SkPathMeasure.h
+**
+** Copyright 2006, Google Inc.
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+** http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#ifndef SkPathMeasure_DEFINED
+#define SkPathMeasure_DEFINED
+
+#include "SkPath.h"
+#include "SkTDArray.h"
+
+class 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).
+ */
+ SkPathMeasure(const SkPath& path, bool forceClosed);
+ ~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 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 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();
+ static void UnitTest();
+#endif
+
+private:
+ SkPath::Iter fIter;
+ const SkPath* fPath;
+ 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 : 15;
+ unsigned fTValue : 15;
+ unsigned fType : 2;
+
+ SkScalar getScalarT() const;
+ };
+ SkTDArray<Segment> fSegments;
+
+ 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_cubic_segs(const SkPoint pts[3], SkScalar distance,
+ int mint, int maxt, int ptIndex);
+ const Segment* distanceToSegment(SkScalar distance, SkScalar* t);
+};
+
+#endif
+