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/*
* Copyright (C) 2014 Vabishchevich Nikolay <vabnick@gmail.com>
*
* This file is part of libass.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef LIBASS_RASTERIZER_H
#define LIBASS_RASTERIZER_H
#include <stddef.h>
#include <stdint.h>
#include "ass.h"
#include "ass_font.h"
enum {
SEGFLAG_DN = 1,
SEGFLAG_UL_DR = 2,
SEGFLAG_EXACT_LEFT = 4,
SEGFLAG_EXACT_RIGHT = 8,
SEGFLAG_EXACT_TOP = 16,
SEGFLAG_EXACT_BOTTOM = 32,
};
// Polyline segment struct
struct segment {
int64_t c;
int32_t a, b, scale, flags;
int32_t x_min, x_max, y_min, y_max;
};
typedef void (*FillSolidTileFunc)(uint8_t *buf, ptrdiff_t stride, int set);
typedef void (*FillHalfplaneTileFunc)(uint8_t *buf, ptrdiff_t stride,
int32_t a, int32_t b, int64_t c, int32_t scale);
typedef void (*FillGenericTileFunc)(uint8_t *buf, ptrdiff_t stride,
const struct segment *line, size_t n_lines,
int winding);
void ass_fill_solid_tile16_c(uint8_t *buf, ptrdiff_t stride, int set);
void ass_fill_solid_tile32_c(uint8_t *buf, ptrdiff_t stride, int set);
void ass_fill_halfplane_tile16_c(uint8_t *buf, ptrdiff_t stride,
int32_t a, int32_t b, int64_t c, int32_t scale);
void ass_fill_halfplane_tile32_c(uint8_t *buf, ptrdiff_t stride,
int32_t a, int32_t b, int64_t c, int32_t scale);
void ass_fill_generic_tile16_c(uint8_t *buf, ptrdiff_t stride,
const struct segment *line, size_t n_lines,
int winding);
void ass_fill_generic_tile32_c(uint8_t *buf, ptrdiff_t stride,
const struct segment *line, size_t n_lines,
int winding);
typedef struct ass_rasterizer {
int outline_error; // acceptable error (in 1/64 pixel units)
int tile_order; // log2(tile_size)
FillSolidTileFunc fill_solid;
FillHalfplaneTileFunc fill_halfplane;
FillGenericTileFunc fill_generic;
int32_t x_min, x_max, y_min, y_max; // usable after rasterizer_set_outline
// internal buffers
struct segment *linebuf[2];
size_t size[2], capacity[2];
} ASS_Rasterizer;
void rasterizer_init(ASS_Rasterizer *rst);
void rasterizer_done(ASS_Rasterizer *rst);
/**
* \brief Convert FreeType outline to polyline and calculate exact bounds
*/
int rasterizer_set_outline(ASS_Rasterizer *rst, const ASS_Outline *path);
/**
* \brief Polyline rasterization function
* \param x0, y0, width, height in: source window (full pixel units)
* \param buf out: aligned output buffer (size = stride * height)
* \param stride output buffer stride (aligned)
* \return zero on error
* Deletes preprocessed polyline after work.
*/
int rasterizer_fill(ASS_Rasterizer *rst, uint8_t *buf, int x0, int y0,
int width, int height, ptrdiff_t stride);
#endif /* LIBASS_RASTERIZER_H */
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