ladybird/Userland/Libraries/LibGfx/QOIWriter.h

/*
 * Copyright (c) 2022, Olivier De Cannière <olivier.decanniere96@gmail.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/Vector.h>
#include <LibGfx/Bitmap.h>

namespace Gfx {

static constexpr Array<u8, 4> qoi_magic_bytes = { 'q', 'o', 'i', 'f' };
static constexpr Array<u8, 8> qoi_end_marker = { 0, 0, 0, 0, 0, 0, 0, 1 };

enum class Colorspace {
    sRGB,
    Linear,
};

enum class Channels {
    RGB,
    RGBA,
};

class QOIWriter {
public:
    static ByteBuffer encode(Gfx::Bitmap const&);

private:
    QOIWriter() = default;

    Vector<u8> m_data;
    void add_header(u32 width, u32 height, Channels, Colorspace);
    void add_rgb_chunk(u8, u8, u8);
    void add_rgba_chunk(u8, u8, u8, u8);
    void add_index_chunk(u32 index);
    void add_diff_chunk(i8 red_difference, i8 green_difference, i8 blue_difference);
    void add_luma_chunk(i8 relative_red_difference, i8 green_difference, i8 relative_blue_difference);
    void add_run_chunk(u32 run_length);
    void add_end_marker();

    Array<Color, 64> running_array;
    static u32 pixel_hash_function(Color pixel);
    void insert_into_running_array(Color pixel);
};

}