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/*
* Copyright 2022-2023 Frederico de Oliveira Linhares
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "qoi.hpp"
#include <array>
#include <fstream>
#include "../binary_reader.hpp"
namespace
{
const char MAGIC[]{"qoif"};
const int HEADER_SIZE{14};
const uint8_t PADDING[8]{0,0,0,0,0,0,0,1};
const unsigned int PIXELS_MAX{400000000};
const int OP_INDEX{0b00000000};
const int OP_DIFF {0b01000000};
const int OP_LUMA {0b10000000};
const int OP_RUN {0b11000000};
const int OP_RGB {0b11111110};
const int OP_RGBA {0b11111111};
const int MASK_2_BITS{0b11000000};
struct RGBA
{
uint8_t red, green, blue, alpha;
RGBA();
RGBA(uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha);
};
RGBA::RGBA():
red{0},
green{0},
blue{0},
alpha{255}
{
}
RGBA::RGBA(uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha):
red{red},
green{green},
blue{blue},
alpha{alpha}
{
}
struct Pixel
{
union
{
RGBA colors;
uint32_t value;
};
Pixel();
Pixel(uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha);
};
Pixel::Pixel():
colors{}
{
}
Pixel::Pixel(uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha):
colors(red, green, blue, alpha)
{
}
inline int
color_hash(const RGBA &colors)
{
return colors.red*3 + colors.green*5 + colors.blue*7 + colors.alpha*11;
}
}
namespace VK::QOI
{
Image::Image(const char *file_path, uint8_t channels):
channels{channels}
{
if(this->channels != 0 && this->channels != 3 && this->channels != 4)
{
throw std::invalid_argument{"invalid number of channels"};
}
BinaryReader input{file_path};
if(input.size() < HEADER_SIZE + (int)sizeof(PADDING))
{
throw std::runtime_error{"invalid QOI file"};
}
input.read_chars(this->header.magic, 4);
this->header.width = input.read_ui32();
this->header.height = input.read_ui32();
this->header.channels = input.read_ui8();
this->header.colorspace = input.read_ui8();
if(this->header.width == 0 || this->header.height == 0 ||
this->header.channels < 3 || this->header.channels > 4 ||
this->header.colorspace > 1 ||
this->header.height >= PIXELS_MAX / this->header.width)
{
throw std::runtime_error{"QOI file have an invalid header"};
}
if(this->channels == 0) this->channels = this->header.channels;
uint32_t num_pixels{this->header.width * this->header.height};
this->pixels_len = num_pixels * this->channels;
this->pixels = new uint8_t[this->pixels_len];
std::array<Pixel, 64> index;
Pixel pixel{};
int chunks_len = input.size() - (int)sizeof(PADDING);
/*
This algorithm is based on the original implementation that is in GitHub:
https://github.com/phoboslab/qoi
For information about the QOI image format, see: https://qoiformat.org/
*/
int pixel_p{0};
int run{0};
for(uint32_t decoded_pixel{0}; decoded_pixel < num_pixels; decoded_pixel++)
{
if(run > 0)
{
run--;
}
else if(input.pointer() < chunks_len)
{
int b1 = input.read_ui8();
if (b1 == OP_RGB)
{
pixel.colors.red = input.read_ui8();
pixel.colors.green = input.read_ui8();
pixel.colors.blue = input.read_ui8();
}
else if (b1 == OP_RGBA)
{
pixel.colors.red = input.read_ui8();
pixel.colors.green = input.read_ui8();
pixel.colors.blue = input.read_ui8();
pixel.colors.alpha = input.read_ui8();
}
else if ((b1 & MASK_2_BITS) == OP_INDEX)
{
pixel = index[b1];
}
else if ((b1 & MASK_2_BITS) == OP_DIFF)
{
pixel.colors.red += ((b1 >> 4) & 0x03) - 2;
pixel.colors.green += ((b1 >> 2) & 0x03) - 2;
pixel.colors.blue += (b1 & 0x03) - 2;
}
else if ((b1 & MASK_2_BITS) == OP_LUMA)
{
int b2 = input.read_ui8();
int vg = (b1 & 0x3f) - 32;
pixel.colors.red += vg - 8 + ((b2 >> 4) & 0x0f);
pixel.colors.green += vg;
pixel.colors.blue += vg - 8 + (b2 & 0x0f);
}
else if ((b1 & MASK_2_BITS) == OP_RUN)
{
run = (b1 & 0x3f);
}
index[color_hash(pixel.colors) % 64] = pixel;
}
this->pixels[pixel_p++] = pixel.colors.red;
this->pixels[pixel_p++] = pixel.colors.green;
this->pixels[pixel_p++] = pixel.colors.blue;
if(this->channels == 4) this->pixels[pixel_p++] = pixel.colors.alpha;
}
}
Image::~Image()
{
delete[] this->pixels;
}
}
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