/* Simple PPM library ----------------------------------------------------------
 * Based on specification: http://netpbm.sourceforge.net/doc/ppm.html
 * -------------------------------------------------------------------------- */

#include "ppm.h"

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

#define __PPM_FLIP__ 1

/* PPM write ---------------------------------------------------------------- */

int
ppm_write(const char *fname, unsigned char *buffer, size_t width, size_t height)
{
    FILE *fs = NULL;
    int result = 0;

    fs = fopen(fname, "w+");
    if (!fs) 
    	goto pgm_write_cleanup;

    fprintf(fs, "P6\n");			/* Magic Number */
    fprintf(fs, "# Simple PPM library\n");	/* Comment */
    fprintf(fs, "%lu %lu\n", width, height);	/* Image width, height */
    fprintf(fs, "255\n");			/* Maximum color value */

    /* Pixel values */
#if __PPM_FLIP__
    for (size_t r = 0; r < height; r++)
    	fwrite(&buffer[width*(height - r - 1)*3], sizeof(unsigned char), width * 3, fs);
#else
    fwrite(buffer, sizeof(unsigned char), width * height * 3, fs); 
#endif
    result = 1;

pgm_write_cleanup:
    if (fs) fclose(fs);
    return result;
}

/* vim: set sts=4 sw=4 ts=8 ft=cpp: ----------------------------------------- */