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

#include "png.h"

int main(void)
{
	char *p[256], c[3];
	FILE *fp;
	int i, j, k;
	png_structp png_ptr;
	png_infop info_ptr;
	
	for (i = 0; i < 256; i++) {
		p[i] = malloc(3 * 256);
	}
	for (i = 0; i < 4; i++) {
		for (j = 0; j < 64; j++) {
			for (k = 0; k < 256; k++) {
				switch (i) {
				case 0:
					c[0] = 0; c[1] = 0; c[2] = 255;
					break;
				case 1:
					c[0] = 0; c[1] = 255; c[2] = 0;
					break;
				case 2:
					c[0] = 255; c[1] = 0; c[2] = 0;
					break;
				case 3:
					c[0] = 255; c[1] = 255; c[2] = 255;
					break;
				}
				p[i * 64 + j][k * 3] = c[0];
				p[i * 64 + j][k * 3 + 1] = c[1];
				p[i * 64 + j][k * 3 + 2] = c[2];
			}
		}
	}
	
	fp = fopen("hogehoge.png", "wb");
	assert(fp);
	
	png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	assert(png_ptr);
	info_ptr = png_create_info_struct(png_ptr);
	assert(info_ptr);
	png_init_io(png_ptr, fp);
	png_set_IHDR(png_ptr, info_ptr, 256, 256, 8, PNG_COLOR_TYPE_RGB, 
	             PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, 
	             PNG_FILTER_TYPE_DEFAULT);
	png_write_info(png_ptr, info_ptr);
	png_write_image(png_ptr, p);
	png_write_end(png_ptr, info_ptr);
	png_destroy_write_struct(&png_ptr, &info_ptr);
	return 0;
}