/*
 * Copyright 2012, Blender Foundation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "stdosl.h"
#include "node_texture.h"

/* Checker */

float checker(point p)
{
	p[0] = (p[0] + 0.00001) * 0.9999;
	p[1] = (p[1] + 0.00001) * 0.9999;
	p[2] = (p[2] + 0.00001) * 0.9999;
	
	int xi = (int)fabs(floor(p[0]));
	int yi = (int)fabs(floor(p[1]));
	int zi = (int)fabs(floor(p[2]));

	if ((xi % 2 == yi % 2) == (zi % 2)) {
		return 1.0;
	}
	else {
		return 0.0;
	}
}

shader node_checker_texture(
	int use_mapping = 0,
	matrix mapping = matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0),
	float Scale = 5.0,
	point Vector = P,
	color Color1 = 0.8,
	color Color2 = 0.2,
	output float Fac = 0.0,
	output color Color = 0.0)
{
	point p = Vector;

	if (use_mapping)
		p = transform(mapping, p);

	Fac = checker(p * Scale);
	if (Fac == 1.0) {
		Color = Color1;
	}
	else {
		Color = Color2;
	}
}