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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkAntiEdge_DEFINED
#define SkAntiEdge_DEFINED
#include "SkFixed.h"
#include "SkTDArray.h"
struct SkBitmap;
struct SkPoint;
struct SkAntiEdge {
SkAntiEdge* fNext; // list in walking order (y, then x, then diag)
SkAntiEdge* fPrev; // reverse in walking order
SkAntiEdge* fLink; // list in connected order, top to bottom
SkFixed fFirstX; // starting X
SkFixed fFirstY; // starting Y
SkFixed fLastX; // ending X
SkFixed fLastY; // ending Y
SkFixed fX0; // computed edge current value (may be off end)
SkFixed fY0;
SkFixed fX; // edge current value (always on edge)
SkFixed fY;
SkFixed fDX; // change in X per unit step in Y
SkFixed fDY; // change in Y per unit step in X
SkFixed fWalkX; // unit step position (integer after initial step)
SkFixed fWalkY;
uint16_t fPartialY; // initial partial coverage in Y (0 .. SkFixed1]
int16_t fWindingSum; // winding including contributions to the left
int8_t fWinding; // 1 or -1 (could be 2 bits)
bool fFinished : 1;
unsigned fDXFlipped : 1; // used as bool and to adjust calculations (0/1)
bool fLinkSet : 1; // set if edge has been attached to another edge
void calcLine();
bool setLine(const SkPoint& p0, const SkPoint& p1);
uint16_t advanceX(SkFixed left);
uint16_t advanceFlippedX(SkFixed left);
void advanceY(SkFixed top);
// FIXME: mark DEBUG
void pointInLine(SkFixed x, SkFixed y);
void pointOnLine(SkFixed x, SkFixed y);
void validate();
};
class SkAntiEdgeBuilder {
public:
void process(const SkPoint* points, int ptCount,
uint8_t* result, int pixelCol, int pixelRow);
private:
int build(const SkPoint pts[], int count);
void calc();
void link();
void sort();
void sort(SkTDArray<SkAntiEdge*>&);
void split();
void split(SkAntiEdge* edge, SkFixed y);
void walk(uint8_t* result, int rowBytes, int height);
SkAntiEdge fHeadEdge;
SkAntiEdge fTailEdge;
SkTDArray<SkAntiEdge> fEdges;
SkTDArray<SkAntiEdge*> fList;
};
void SkAntiEdge_Test();
void CreateSweep(SkBitmap* , float width);
void CreateHorz(SkBitmap* );
void CreateVert(SkBitmap* );
void CreateAngle(SkBitmap* sweep, float angle);
#endif
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