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-rw-r--r--src/core/SkPerspIter.h48
1 files changed, 48 insertions, 0 deletions
diff --git a/src/core/SkPerspIter.h b/src/core/SkPerspIter.h
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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 SkPerspIter_DEFINED
+#define SkPerspIter_DEFINED
+
+#include "SkMatrix.h"
+
+class SkPerspIter {
+public:
+ /** Iterate a line through the matrix [x,y] ... [x+count-1, y].
+ @param m The matrix we will be iterating a line through
+ @param x The initial X coordinate to be mapped through the matrix
+ @param y The initial Y coordinate to be mapped through the matrix
+ @param count The number of points (x,y) (x+1,y) (x+2,y) ... we will eventually map
+ */
+ SkPerspIter(const SkMatrix& m, SkScalar x, SkScalar y, int count);
+
+ /** Return the buffer of [x,y] fixed point values we will be filling.
+ This always returns the same value, so it can be saved across calls to
+ next().
+ */
+ const SkFixed* getXY() const { return fStorage; }
+
+ /** Return the number of [x,y] pairs that have been filled in the getXY() buffer.
+ When this returns 0, the iterator is finished.
+ */
+ int next();
+
+private:
+ enum {
+ kShift = 4,
+ kCount = (1 << kShift)
+ };
+ const SkMatrix& fMatrix;
+ SkFixed fStorage[kCount * 2];
+ SkFixed fX, fY;
+ SkScalar fSX, fSY;
+ int fCount;
+};
+
+#endif