blender/intern/cycles/kernel/shaders/node_hsv.osl

/*
 * 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 "node_color.h"

shader node_hsv(float Hue = 0.5,
                float Saturation = 1.0,
                float Value = 1.0,
                float Fac = 0.5,
                color ColorIn = 0.0,
                output color ColorOut = 0.0)
{
  color Color = rgb_to_hsv(ColorIn);

  // remember: fmod doesn't work for negative numbers
  Color[0] = fmod(Color[0] + Hue + 0.5, 1.0);
  Color[1] = clamp(Color[1] * Saturation, 0.0, 1.0);
  Color[2] *= Value;

  Color = hsv_to_rgb(Color);

  // Clamp color to prevent negative values cauzed by oversaturation.
  Color[0] = max(Color[0], 0.0);
  Color[1] = max(Color[1], 0.0);
  Color[2] = max(Color[2], 0.0);

  ColorOut = mix(ColorIn, Color, Fac);
}