#include <stdio.h>
#include <stdint.h>
#include <assert.h>
#include <stdlib.h>
struct Psd{
int64_t width;
int64_t height;
};
struct Channel{
uint8_t *pointer;
int64_t ID;
};
struct Layer{
uint64_t channel_count;
Channel channel[4]; // max 4 at them moment
int64_t top;
int64_t bottom;
int64_t left;
int64_t right;
};
struct Clamp{
int64_t x;
int64_t y;
int64_t w;
int64_t h;
};
uint8_t *decompress_RLE(
Psd *psd,
Layer *layer,
uint8_t *file_data)
{
uint64_t total_height = layer->bottom - layer->top;
Clamp clamp = {};
if(layer->left < 0) clamp.x = layer->left;
if(layer->top < 0) clamp.y = layer->top;
if(layer->right > psd->width) clamp.w = psd->width - layer->left;
else clamp.w = layer->right - layer->left;
if(layer->bottom > psd->height) clamp.h = psd->height - layer->top;
else clamp.h = layer->bottom - layer->top;
int64_t data_size = clamp.w * clamp.h * 4;
if(data_size < 0) data_size = 0;
uint8_t *image_data;
if(data_size != 0)
{
image_data = (uint8_t *)malloc(data_size);
}
for(size_t CC = 0; CC < layer->channel_count; ++CC)
{
file_data = layer->channel[CC].pointer;
uint16_t compression = (uint16_t)file_data[0] * 256 + (uint16_t)file_data[1];
file_data += 2;
double opacity = 1;
int64_t pixel_pos_c;
if(layer->channel[CC].ID == -1) pixel_pos_c = 3;
else if(layer->channel[CC].ID == 0) pixel_pos_c = 0;
else if(layer->channel[CC].ID == 1) pixel_pos_c = 1;
else if(layer->channel[CC].ID == 2) pixel_pos_c = 2;
//else assert(false);
if(compression == 1)
{
uint16_t *line_info = (uint16_t *)malloc(total_height * sizeof(*line_info));
for(size_t LINE = 0; LINE < total_height; ++LINE)
{
line_info[LINE] = (uint16_t)file_data[0] * 256 + (uint16_t)file_data[1];
file_data += sizeof(*line_info);
}
int64_t pixel_pos_y = clamp.y;
for(size_t LINE = 0; LINE < total_height; ++LINE)
{
uint8_t *layer_end = file_data + line_info[LINE];
if(pixel_pos_y >= 0)
{
if(pixel_pos_y < clamp.h + clamp.y)
{
int64_t pixel_pos_x = clamp.x;
while(file_data < layer_end)
{
int8_t head = *file_data;
++file_data;
if(head >= 0)
{
for(size_t i = 0; i < 1 + head; ++i)
{
uint8_t pixel = *file_data * opacity;
++file_data;
if(pixel_pos_x >= 0 && pixel_pos_x < clamp.x + clamp.w)
{
image_data[pixel_pos_c + (pixel_pos_x*4) + (pixel_pos_y*(clamp.w+clamp.x)*4)] = pixel;
}
++pixel_pos_x;
}
}
else if(head > -128)
{
uint8_t pixel = *file_data * opacity;
++file_data;
for(size_t i = 0; i < 1 - head; ++i)
{
if(pixel_pos_x >= 0 && pixel_pos_x < clamp.x + clamp.y)
{
image_data[pixel_pos_c + (pixel_pos_x*4) + (pixel_pos_y*(clamp.w+clamp.x)*4)] = pixel;
}
++pixel_pos_x;
}
}
else
{
++file_data;
}
}
}
else
{
break;
}
}
else
{
file_data = layer_end;
}
++pixel_pos_y;
free(line_info);
}
}
else if(compression == 0)
{
//todo
}
}
return image_data;
}
