/*
 *	FloatImg library from tTh
 */

#include  <stdio.h>

#include  "../floatimg.h"

/* -------------------------------------------------------------- */
/*	global vars from main
 */
extern	int	verbosity;

/* -------------------------------------------------------------- */

int fimg_mix_rgb_gray(FloatImg *img, float mix)
{
int		x, y, p;
float		gr;

if (FIMG_TYPE_RGB != img->type) {
	fprintf(stderr, "%s bad type\n", __func__);
	return -6;
	}

for (y=0; y<img->height; y++) {
	p = y * img->width;
	for (x=0; x<img->width; x++) {

		gr = (img->R[p] + img->G[p] + img->R[p]) / 3.0;

		img->R[p] = ((gr * mix) + (img->R[p] * (1.0-mix))) / 2.0;
		img->G[p] = ((gr * mix) + (img->G[p] * (1.0-mix))) / 2.0;
		img->B[p] = ((gr * mix) + (img->B[p] * (1.0-mix))) / 2.0;

		p++;			/* next pixel in the row */
		}

	}

return 0;
}

/* -------------------------------------------------------------- */