stb_to_c_array.c

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

int w, h, channels;
unsigned char *data;
FILE *file;

void cleanup()
{
    if (data) stbi_image_free(data);
    if (file) fclose(file);
}

int main(int argc, char *argv[])
{
    // TODO(dlb): Take these from argv if you want to use this program from command line.
    const char *in_file = "test.png";
    const char *out_file = "text.txt";

    // NOTE(dlb): The "4" here forces stb_image to always output RGBA arrays, even for textures
    // with less than 4 channels. Feel free to change this (see stb_image.h lines 124 - 160
    // for details)
    data = stbi_load(in_file, &w, &h, &channels, 4);
    if (!data) {
        printf("Error: Failed to open %s for read.\n", out_file);
        cleanup();
        return -1;
    }

    int bytes = w * h * 4;
    if (!bytes) {
        printf("Error: Image is 0 bytes.\n");
        cleanup();
        return -2;
    }

    file = fopen(out_file, "w");
    if (!file) {
        printf("Error: Failed to open %s for write.\n", out_file);
        cleanup();
        return -3;
    }

    fprintf(file, "unsigned char pixels_rgba[] = {\n    ");
    fprintf(file, "0x%02x", data[0]);

    // how many columns to format the byte data in
    int format_columns = 16;
    for (int i = 1; i < bytes; i++) {
        fprintf(file, ", ");
        if (i % format_columns == 0 && i < bytes - 1) {
            fprintf(file, "\n    ");
        }
        fprintf(file, "0x%02x", data[i]);
    }
    fprintf(file, "\n};");

    cleanup();
    return 0;
}