/*
 * 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"

/* Brick */

float brick_noise(int n) /* fast integer noise */
{
	int nn;
	n = (n >> 13) ^ n;
	nn = (n * (n * n * 60493 + 19990303) + 1376312589) & 2147483647;
	return 0.5 * ((float)nn / 1073741824.0);
}

float brick(point p, float mortar_size, float bias,
	float BrickWidth, float row_height, float offset_amount, int offset_frequency,
	float squash_amount, int squash_frequency, float tint)
{
	int bricknum, rownum;
	float offset = 0.0;
	float brick_width = BrickWidth;
	float x, y;

	rownum = (int)floor(p[1] / row_height);
	
	if (offset_frequency && squash_frequency) {
		brick_width *= ((int)(rownum) % squash_frequency) ? 1.0 : squash_amount;                /* squash */
		offset       = ((int)(rownum) % offset_frequency) ? 0 : (brick_width * offset_amount);  /* offset */
	}

	bricknum = (int)floor((p[0] + offset) / brick_width);

	x = (p[0] + offset) - brick_width * bricknum;
	y = p[1] - row_height * rownum;

	tint = clamp((brick_noise((rownum << 16) + (bricknum & 65535)) + bias), 0.0, 1.0);

	return (x < mortar_size || y < mortar_size ||
	        x > (brick_width - mortar_size) ||
	        y > (row_height - mortar_size)) ? 1.0 : 0.0;
}

shader node_brick_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 Offset = 0.5,
	int OffsetFrequency = 2,
	float Squash = 1.0,
	int SquashFrequency = 1,
	point Vector = P,
	color Color1 = color(0.2, 0.2, 0.2),
	color Color2 = color(0.8, 0.8, 0.8),
	color Mortar = color(0.0, 0.0, 0.0),
	float Scale = 5.0,
	float MortarSize = 0.02,
	float Bias = 0.0,
	float BrickWidth = 0.5,
	float RowHeight = 0.25,
	output float Fac = 0.0,
	output color Color = color(0.2, 0.2, 0.2))
{
	point p = Vector;

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

	float tint = 0.0;
	color Col = Color1;
	
	Fac = brick(p * Scale, MortarSize, Bias, BrickWidth, RowHeight,
		Offset, OffsetFrequency, Squash, SquashFrequency, tint);
		
	if (Fac != 1.0) {
		float facm = 1.0 - tint;

		Col[0] = facm * (Color1[0]) + tint * Color2[0];
		Col[1] = facm * (Color1[1]) + tint * Color2[1];
		Col[2] = facm * (Color1[2]) + tint * Color2[2];
	}
	
	Color = (Fac == 1.0) ? Mortar: Col;
}