nsgif.h

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/*
 * Copyright 2004 Richard Wilson <richard.wilson@netsurf-browser.org>
 * Copyright 2008 Sean Fox <dyntryx@gmail.com>
 * Copyright 2013-2022 Michael Drake <tlsa@netsurf-browser.org>
 *
 * This file is part of NetSurf's libnsgif, http://www.netsurf-browser.org/
 * Licenced under the MIT License,
 *                http://www.opensource.org/licenses/mit-license.php
 */
 
#ifndef NSNSGIF_H
#define NSNSGIF_H
 
#include <stdint.h>
#include <stdbool.h>
#include <inttypes.h>
 
#define NSGIF_INFINITE (UINT32_MAX)
 
#define NSGIF_MAX_COLOURS 256
 
typedef struct nsgif nsgif_t;
 
typedef struct nsgif_rect {
    uint32_t x0;
    uint32_t y0;
    uint32_t x1;
    uint32_t y1;
} nsgif_rect_t;
 
typedef enum {
    NSGIF_OK,
 
    NSGIF_ERR_OOM,
 
    NSGIF_ERR_DATA,
 
    NSGIF_ERR_BAD_FRAME,
 
    NSGIF_ERR_DATA_FRAME,
 
    NSGIF_ERR_END_OF_DATA,
 
    NSGIF_ERR_DATA_COMPLETE,
 
    NSGIF_ERR_FRAME_DISPLAY,
 
    NSGIF_ERR_ANIMATION_END,
} nsgif_error;
 
typedef enum nsgif_bitmap_fmt {
    NSGIF_BITMAP_FMT_R8G8B8A8,
 
    NSGIF_BITMAP_FMT_B8G8R8A8,
 
    NSGIF_BITMAP_FMT_A8R8G8B8,
 
    NSGIF_BITMAP_FMT_A8B8G8R8,
 
    NSGIF_BITMAP_FMT_RGBA8888,
 
    NSGIF_BITMAP_FMT_BGRA8888,
 
    NSGIF_BITMAP_FMT_ARGB8888,
 
    NSGIF_BITMAP_FMT_ABGR8888,
} nsgif_bitmap_fmt_t;
 
typedef void nsgif_bitmap_t;
 
typedef struct nsgif_bitmap_cb_vt {
    nsgif_bitmap_t* (*create)(int width, int height);
 
    void (*destroy)(nsgif_bitmap_t *bitmap);
 
    uint8_t* (*get_buffer)(nsgif_bitmap_t *bitmap);
 
    /* The following functions are optional. */
 
    void (*set_opaque)(nsgif_bitmap_t *bitmap, bool opaque);
 
    bool (*test_opaque)(nsgif_bitmap_t *bitmap);
 
    void (*modified)(nsgif_bitmap_t *bitmap);
 
    uint32_t (*get_rowspan)(nsgif_bitmap_t *bitmap);
} nsgif_bitmap_cb_vt;
 
const char *nsgif_strerror(nsgif_error err);
 
nsgif_error nsgif_create(
        const nsgif_bitmap_cb_vt *bitmap_vt,
        nsgif_bitmap_fmt_t bitmap_fmt,
        nsgif_t **gif_out);
 
void nsgif_destroy(nsgif_t *gif);
 
nsgif_error nsgif_data_scan(
        nsgif_t *gif,
        size_t size,
        const uint8_t *data);
 
void nsgif_data_complete(
        nsgif_t *gif);
 
nsgif_error nsgif_frame_prepare(
        nsgif_t *gif,
        nsgif_rect_t *area,
        uint32_t *delay_cs,
        uint32_t *frame_new);
 
nsgif_error nsgif_frame_decode(
        nsgif_t *gif,
        uint32_t frame,
        nsgif_bitmap_t **bitmap);
 
nsgif_error nsgif_reset(
        nsgif_t *gif);
 
typedef struct nsgif_info {
    uint32_t width;
    uint32_t height;
    uint32_t frame_count;
    int loop_max;
    uint32_t background;
    bool global_palette;
} nsgif_info_t;
 
enum nsgif_disposal {
    NSGIF_DISPOSAL_UNSPECIFIED,   
    NSGIF_DISPOSAL_NONE,          
    NSGIF_DISPOSAL_RESTORE_BG,    
    NSGIF_DISPOSAL_RESTORE_PREV,  
    NSGIF_DISPOSAL_RESTORE_QUIRK, 
};
 
const char *nsgif_str_disposal(enum nsgif_disposal disposal);
 
typedef struct nsgif_frame_info {
    bool display;
    bool transparency;
    bool local_palette;
    bool interlaced;
    uint8_t disposal;
    uint32_t delay;
 
    nsgif_rect_t rect;
} nsgif_frame_info_t;
 
const nsgif_info_t *nsgif_get_info(const nsgif_t *gif);
 
const nsgif_frame_info_t *nsgif_get_frame_info(
        const nsgif_t *gif,
        uint32_t frame);
 
void nsgif_global_palette(
        const nsgif_t *gif,
        uint32_t table[NSGIF_MAX_COLOURS],
        size_t *entries);
 
bool nsgif_local_palette(
        const nsgif_t *gif,
        uint32_t frame,
        uint32_t table[NSGIF_MAX_COLOURS],
        size_t *entries);
 
void nsgif_set_frame_delay_behaviour(
        nsgif_t *gif,
        uint16_t delay_min,
        uint16_t delay_default);
 
#endif