CgeScanline/CgeScanline.h

#ifndef CGE_SCANLINE_H
#define CGE_SCANLINE_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stdint.h>
#include <stddef.h>

enum CgeScanlineFillRule {
    CGE_SCANLINE_ODD_EVEN = 0,
    CGE_SCANLINE_NON_ZERO = (1 << 0),
};

enum CgeScanlineCode {
    CGE_SCANLINE_EOK,
    CGE_SCANLINE_EDONE,
    CGE_SCANLINE_EAET,
    CGE_SCANLINE_ESPANS,
};

typedef struct CgeScanlineEdge {
    uint32_t startX;
    uint32_t startY;
    uint32_t endY;
    uint32_t step;
    uint32_t error;
    uint32_t threshold;
    uint32_t dir;
    int winding;
} CgeScanlineEdge;

typedef struct CgeScanlineEdgeTable {
    size_t index;
    uint32_t x;
    uint32_t error;
} CgeScanlineEdgeTable;

typedef struct CgeScanlineSpan {
    uint32_t start;
    uint32_t end;
} CgeScanlineSpan;

typedef void (*CgeScanlineRowCallback)(uint32_t y, CgeScanlineSpan *spans,
                                       size_t size, void *userData);

typedef void (*CgeScanlineLineToCallback)(uint32_t x0, uint32_t y0,
                                          uint32_t x1, uint32_t y1,
                                          void *userData);

typedef struct CgeScanlineState {
    CgeScanlineEdge *edge;
    size_t edgeSize;
    CgeScanlineEdgeTable *aet;
    size_t aetCapacity;
    CgeScanlineSpan *span;
    size_t spanCapacity;
    CgeScanlineRowCallback callback;
    void *userData;
    int flags;

    /* Internal state - do not edit */
    uint32_t yCurrent;
    uint32_t yMax;
    size_t aetSize;
    size_t edgeCursor;
} CgeScanlineState;

int CgeScanlineStateInit(CgeScanlineState *state, CgeScanlineEdge *edge,
                         size_t edgeSize, CgeScanlineEdgeTable *aet,
                         size_t aetCapacity, CgeScanlineSpan *span,
                         size_t spanCapacity, CgeScanlineRowCallback callback,
                         void *userData, int flags);

int CgeScanlineStateNext(CgeScanlineState *state, int *result);

int CgeScanlineEdgeAdd(CgeScanlineEdge *edge, uint32_t aX, uint32_t aY,
                       uint32_t bX, uint32_t bY);

int CgeScanlineSpans(CgeScanlineEdge *edge, size_t edgeSize,
                     CgeScanlineRowCallback callback, void *userData,
                     int flags);

void CgeScanlineBezierCubicFlatten(uint32_t x0, uint32_t y0, uint32_t x1,
                                   uint32_t y1, uint32_t x2, uint32_t y2,
                                   uint32_t x3, uint32_t y3, uint32_t flatness,
                                   CgeScanlineLineToCallback lineTo,
                                   void *userData);

void CgeScanlineBezierQuadFlatten(uint32_t x0, uint32_t y0, uint32_t x1,
                                  uint32_t y1, uint32_t x2, uint32_t y2,
                                  uint32_t flatness,
                                  CgeScanlineLineToCallback lineTo,
                                  void *userData);

size_t CgeScanlineBezierCubicEdges(CgeScanlineEdge *edge, size_t edgeSize,
                                   uint32_t x0, uint32_t y0, uint32_t x1,
                                   uint32_t y1, uint32_t x2, uint32_t y2,
                                   uint32_t x3, uint32_t y3, uint32_t flatness);

size_t CgeScanlineBezierQuadEdges(CgeScanlineEdge *edge, size_t edgeSize,
                                  uint32_t x0, uint32_t y0, uint32_t x1,
                                  uint32_t y1, uint32_t x2, uint32_t y2,
                                  uint32_t flatness);

#ifdef __cplusplus
}
#endif

#endif /* CGE_SCANLINE_H */