grab from latest android

git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 115 insertions, 0 deletions

diff --git a/include/core/SkPathMeasure.h b/include/core/SkPathMeasure.h
new file mode 100644
index 0000000000..5ab97cacfd
--- /dev/null
+++ b/include/core/SkPathMeasure.h
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2006 The Android Open Source Project
+ *
+ * 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
+