nsgif.hpp

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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
 */

 
#pragma once
 
#include "fl/stl/int.h"
#include "fl/stl/noexcept.h"
#include <stdbool.h>
 
namespace fl {
namespace third_party {

#define NSGIF_INFINITE (0xFFFFFFFFU)

#define NSGIF_MAX_COLOURS 256

typedef struct nsgif nsgif_t;

typedef struct nsgif_rect {
    fl::u32 x0;
    fl::u32 y0;
    fl::u32 x1;
    fl::u32 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);

    fl::u8* (*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);

    fl::u32 (*get_rowspan)(nsgif_bitmap_t *bitmap);
} nsgif_bitmap_cb_vt;

const char *nsgif_strerror(nsgif_error err) FL_NOEXCEPT;

nsgif_error nsgif_create(
        const nsgif_bitmap_cb_vt *bitmap_vt,
        nsgif_bitmap_fmt_t bitmap_fmt,
        nsgif_t **gif_out) FL_NOEXCEPT;

void nsgif_destroy(nsgif_t *gif) FL_NOEXCEPT;

nsgif_error nsgif_data_scan(
        nsgif_t *gif,
        fl::size size,
        const fl::u8 *data) FL_NOEXCEPT;

void nsgif_data_complete(
        nsgif_t *gif) FL_NOEXCEPT;

nsgif_error nsgif_frame_prepare(
        nsgif_t *gif,
        nsgif_rect_t *area,
        fl::u32 *delay_cs,
        fl::u32 *frame_new) FL_NOEXCEPT;

nsgif_error nsgif_frame_decode(
        nsgif_t *gif,
        fl::u32 frame,
        nsgif_bitmap_t **bitmap) FL_NOEXCEPT;

nsgif_error nsgif_reset(
        nsgif_t *gif) FL_NOEXCEPT;

typedef struct nsgif_info {
    fl::u32 width;
    fl::u32 height;
    fl::u32 frame_count;
    int loop_max;
    fl::u32 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) FL_NOEXCEPT;

typedef struct nsgif_frame_info {
    bool display;
    bool transparency;
    bool local_palette;
    bool interlaced;
    fl::u8 disposal;
    fl::u32 delay;

    nsgif_rect_t rect;
} nsgif_frame_info_t;

const nsgif_info_t *nsgif_get_info(const nsgif_t *gif) FL_NOEXCEPT;

const nsgif_frame_info_t *nsgif_get_frame_info(
        const nsgif_t *gif,
        fl::u32 frame) FL_NOEXCEPT;

void nsgif_global_palette(
        const nsgif_t *gif,
        fl::u32 table[NSGIF_MAX_COLOURS],
        fl::size *entries) FL_NOEXCEPT;

bool nsgif_local_palette(
        const nsgif_t *gif,
        fl::u32 frame,
        fl::u32 table[NSGIF_MAX_COLOURS],
        fl::size *entries) FL_NOEXCEPT;

void nsgif_set_frame_delay_behaviour(
        nsgif_t *gif,
        fl::u16 delay_min,
        fl::u16 delay_default) FL_NOEXCEPT;
 
} // namespace third_party
} // namespace fl