/*
 * Copyright 2011-2013 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License
 */

#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];
	}
}