armorpaint/base/tools/amake/aimage.c

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>

#include "../../sources/libs/lz4x.h"
#define STBI_KEEP_STDIO
#define STB_IMAGE_IMPLEMENTATION
#include "../../sources/libs/stb_image.h"
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "../../sources/libs/stb_image_write.h"
#define STB_IMAGE_RESIZE_IMPLEMENTATION
#include "stb_image_resize.h"

typedef struct image {
    void *data;
    int width;
    int height;
    bool is_hdr;
} gpu_texture_t;

static bool ends_with(const char *s, const char *end) {
	size_t len_s = strlen(s);
	size_t len_end = strlen(end);
	return strncmp(s + len_s - len_end, end, len_end) == 0;
}

static gpu_texture_t read_png_jpg(const char *filename) {
    int width, height, n;
    char *data = stbi_load(filename, &width, &height, &n, 4);
    gpu_texture_t img = { .data = data, .width = width, .height = height, .is_hdr = false };
    return img;
}

static gpu_texture_t read_hdr(const char *filename) {
	int width, height, n;
    float *data = stbi_loadf(filename, &width, &height, &n, 4);
    gpu_texture_t img = { .data = data, .width = width, .height = height, .is_hdr = true };
    return img;
}

static void *scale_image(gpu_texture_t img, int width, int height) {
    unsigned char *scaled = malloc(width * height * 4);
    stbir_resize_uint8_generic(img.data, img.width, img.height, img.width * 4, scaled, width, height, width * 4, 4, 3, 0,
                               STBIR_EDGE_CLAMP, STBIR_FILTER_BOX, STBIR_COLORSPACE_SRGB, 0);
    return scaled;
}

// Courtesy of https://github.com/Kode/kraffiti

static void write_ico_header(FILE *file) {
	fputc(0, file);
	fputc(0, file);
    short type_ico = 1;
    fwrite(&type_ico, 1, 2, file);
    short img_count = 5;
    fwrite(&img_count, 1, 2, file);
}

static void write_ico_entry(FILE *file, int width, int height, int size, int offset) {
	fputc(width == 256 ? 0 : width, file);
	fputc(height == 256 ? 0 : height, file);
	fputc(0, file);
	fputc(0, file);
    short color_planes = 1;
    fwrite(&color_planes, 1, 2, file);
    short bpp = 32;
    fwrite(&bpp, 1, 2, file);
    fwrite(&size, 1, 4, file);
    fwrite(&offset, 1, 4, file);
}

void export_ico(const char *from, const char *to) {
    gpu_texture_t img = read_png_jpg(from);
    FILE *file = fopen(to, "wb");

    unsigned char *data256 = scale_image(img, 256, 256);
    unsigned char *data48 = scale_image(img, 48, 48);
    unsigned char *data32 = scale_image(img, 32, 32);
    unsigned char *data24 = scale_image(img, 24, 24);
    unsigned char *data16 = scale_image(img, 16, 16);
    int comp = 4;
    int png256_len;
    int png48_len;
    int png32_len;
    int png24_len;
    int png16_len;
    unsigned char *png256 = stbi_write_png_to_mem(data256, 256 * comp, 256, 256, comp, &png256_len);
    unsigned char *png48 = stbi_write_png_to_mem(data48, 48 * comp, 48, 48, comp, &png48_len);
    unsigned char *png32 = stbi_write_png_to_mem(data32, 32 * comp, 32, 32, comp, &png32_len);
    unsigned char *png24 = stbi_write_png_to_mem(data24, 24 * comp, 24, 24, comp, &png24_len);
    unsigned char *png16 = stbi_write_png_to_mem(data16, 16 * comp, 16, 16, comp, &png16_len);

    write_ico_header(file);
    const int ico_header_size = 6;
    const int ico_entry_size = 16;
	int ico_offset = ico_header_size + ico_entry_size * 5;
	write_ico_entry(file, 16, 16, png16_len, ico_offset);
	ico_offset += png16_len;
	write_ico_entry(file, 24, 24, png24_len, ico_offset);
	ico_offset += png24_len;
	write_ico_entry(file, 32, 32, png32_len, ico_offset);
	ico_offset += png32_len;
	write_ico_entry(file, 48, 48, png48_len, ico_offset);
	ico_offset += png48_len;
	write_ico_entry(file, 256, 256, png256_len, ico_offset);

    fwrite(png16, 1, png16_len, file);
    fwrite(png24, 1, png24_len, file);
    fwrite(png32, 1, png32_len, file);
    fwrite(png48, 1, png48_len, file);
    fwrite(png256, 1, png256_len, file);
	fclose(file);

    free(data256);
    free(data48);
    free(data32);
    free(data24);
    free(data16);
    free(png256);
    free(png48);
    free(png32);
    free(png24);
    free(png16);
}

void export_png(const char *from, const char *to, int width, int height) {
    gpu_texture_t img = read_png_jpg(from);

    if (width > 0 && height > 0) {
        unsigned char *scaled = scale_image(img, width, height);
        free(img.data);
        img.data = scaled;
    }
    else {
        width = img.width;
        height = img.height;
    }

    int comp = 4;
    stbi_write_png(to, width, height, comp, (unsigned char *)img.data, width * comp);
    free(img.data);
}

static void write_k(int width, int height, const char *format, char *data, int size, const char *filename) {
	FILE *file = fopen(filename, "wb");
	fputc((unsigned char)width, file);
	fputc((unsigned char)(width >> 8), file);
	fputc((unsigned char)(width >> 16), file);
	fputc((unsigned char)(width >> 24), file);
	fputc((unsigned char)height, file);
	fputc((unsigned char)(height >> 8), file);
	fputc((unsigned char)(height >> 16), file);
	fputc((unsigned char)(height >> 24), file);
	fputc(format[0], file);
	fputc(format[1], file);
	fputc(format[2], file);
	fputc(format[3], file);
	fwrite(data, 1, size, file);
	fclose(file);
}

void export_k(const char *from, const char *to) {
    gpu_texture_t img;
	if (ends_with(from, ".hdr")) {
		img = read_hdr(from);
    }
	else {
	    img = read_png_jpg(from);
    }

    int pixel_size = img.is_hdr ? 16 : 4;
    int max = LZ4_compress_bound(img.width * img.height * pixel_size);
    char *compressed = malloc(max);
    int compressed_size = LZ4_compress_default((char *)img.data, compressed, img.width * img.height * pixel_size, max);
    write_k(img.width, img.height, img.is_hdr ? "LZ4F" : "LZ4 ", compressed, compressed_size, to);
    free(compressed);
    free(img.data);
}