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

// https://github.com/nothings/stb/blob/master/stb_image_write.h
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

int main() {
    int resx = 640;
    int resy = 480;
    unsigned char* pixels = (unsigned char*)malloc(sizeof(unsigned char) * (3 * resx * resy));

    // Create pixel data using linear gradients for red and green
    // (0,0) is the upper-left corner for most common image formats
    for (int j = 0; j < resy; j++) {
        for (int i = 0; i < resx; i++) {
            int k = j*resx + i;
            pixels[3*k + 0] = 255*i/(resx-1.0);
            pixels[3*k + 1] = 255*j/(resy-1.0);
            pixels[3*k + 2] = 128;
        }
    }

    {
        char str[128];
        sprintf(str, "test.png");

        if (stbi_write_png(str, resx, resy, 3, pixels, 3*resx)) {
            printf("File '%s' successfully saved\n", str); fflush(stdout);
        } else {
            printf("File '%s' error\n", str); fflush(stdout);
        }
    }

    {
        char str[128];
        sprintf(str, "test.bmp");

        if (stbi_write_bmp(str, resx, resy, 3, pixels)) {
            printf("File '%s' successfully saved\n", str); fflush(stdout);
        } else {
            printf("File '%s' error\n", str); fflush(stdout);
        }
    }

    // stb_image_write.h also support .tga and .hdr

    free(pixels);

    return 0;
}