grab from latest android
git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkEdge.h b/src/core/SkEdge.h
new file mode 100644
index 0000000..5b0cc75
--- /dev/null
+++ b/src/core/SkEdge.h
@@ -0,0 +1,93 @@
+/* libs/graphics/sgl/SkEdge.h
+**
+** Copyright 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 SkEdge_DEFINED
+#define SkEdge_DEFINED
+
+#include "SkRect.h"
+
+struct SkEdge {
+ enum Type {
+ kLine_Type,
+ kQuad_Type,
+ kCubic_Type
+ };
+
+ SkEdge* fNext;
+ SkEdge* fPrev;
+
+ SkFixed fX;
+ SkFixed fDX;
+ int32_t fFirstY;
+ int32_t fLastY;
+ int8_t fCurveCount; // only used by kQuad(+) and kCubic(-)
+ uint8_t fCurveShift; // appled to all Dx/DDx/DDDx except for fCubicDShift exception
+ uint8_t fCubicDShift; // applied to fCDx and fCDy only in cubic
+ int8_t fWinding; // 1 or -1
+
+ int setLine(const SkPoint& p0, const SkPoint& p1, const SkIRect* clip,
+ int shiftUp);
+ inline int updateLine(SkFixed ax, SkFixed ay, SkFixed bx, SkFixed by);
+ void chopLineWithClip(const SkIRect& clip);
+
+ inline bool intersectsClip(const SkIRect& clip) const {
+ SkASSERT(fFirstY < clip.fBottom);
+ return fLastY >= clip.fTop;
+ }
+
+#ifdef SK_DEBUG
+ void dump() const {
+ #ifdef SK_CAN_USE_FLOAT
+ SkDebugf("edge: firstY:%d lastY:%d x:%g dx:%g w:%d\n", fFirstY, fLastY, SkFixedToFloat(fX), SkFixedToFloat(fDX), fWinding);
+ #else
+ SkDebugf("edge: firstY:%d lastY:%d x:%x dx:%x w:%d\n", fFirstY, fLastY, fX, fDX, fWinding);
+ #endif
+ }
+
+ void validate() const {
+ SkASSERT(fPrev && fNext);
+ SkASSERT(fPrev->fNext == this);
+ SkASSERT(fNext->fPrev == this);
+
+ SkASSERT(fFirstY <= fLastY);
+ SkASSERT(SkAbs32(fWinding) == 1);
+ }
+#endif
+};
+
+struct SkQuadraticEdge : public SkEdge {
+ SkFixed fQx, fQy;
+ SkFixed fQDx, fQDy;
+ SkFixed fQDDx, fQDDy;
+ SkFixed fQLastX, fQLastY;
+
+ int setQuadratic(const SkPoint pts[3], const SkIRect* clip, int shiftUp);
+ int updateQuadratic();
+};
+
+struct SkCubicEdge : public SkEdge {
+ SkFixed fCx, fCy;
+ SkFixed fCDx, fCDy;
+ SkFixed fCDDx, fCDDy;
+ SkFixed fCDDDx, fCDDDy;
+ SkFixed fCLastX, fCLastY;
+
+ int setCubic(const SkPoint pts[4], const SkIRect* clip, int shiftUp);
+ int updateCubic();
+};
+
+#endif