serenity/Userland/Libraries/LibGfx/QOIWriter.h
Olivier De Canniere 44a5558525 LibGfx: Add a QOI image format encoder
Previously only a QOI image decoder was available on the system. This
commit adds an encoder as well.

For now it only handles images with 4 channels (RGBA).
2022-04-13 15:21:27 +01:00

49 lines
1.1 KiB
C++

/*
* 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);
};
}