/*
 * Copyright 2011, 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 "oslutil.h"

shader node_rgb_ramp(
	color ramp_color[RAMP_TABLE_SIZE] = {0.0},
	float ramp_alpha[RAMP_TABLE_SIZE] = {0.0},
	int ramp_interpolate = 1,

	float Fac = 0.0,
	output color Color = 0.0,
	output float Alpha = 1.0)
{
	float f = clamp(Fac, 0.0, 1.0) * (RAMP_TABLE_SIZE - 1);

	/* clamp int as well in case of NaN */
	int i = (int)f;
	if (i < 0) i = 0;
	if (i >= RAMP_TABLE_SIZE) i = RAMP_TABLE_SIZE - 1;
	float t = f - (float)i;

	Color = ramp_color[i];
	Alpha = ramp_alpha[i];

	if (ramp_interpolate && t > 0.0) {
		Color = (1.0 - t) * Color + t * ramp_color[i + 1];
		Alpha = (1.0 - t) * Alpha + t * ramp_alpha[i + 1];
	}
}