blender-archive/intern/cycles/kernel/shaders/node_map_range.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 "stdcycles.h"

float safe_divide(float a, float b)
{
  return (b != 0.0) ? a / b : 0.0;
}

float smootherstep(float edge0, float edge1, float x)
{
  float t = clamp(safe_divide((x - edge0), (edge1 - edge0)), 0.0, 1.0);
  return t * t * t * (t * (t * 6.0 - 15.0) + 10.0);
}

shader node_map_range(string range_type = "linear",
                      float Value = 1.0,
                      float FromMin = 0.0,
                      float FromMax = 1.0,
                      float ToMin = 0.0,
                      float ToMax = 1.0,
                      float Steps = 4.0,
                      output float Result = 0.0)
{
  if (FromMax != FromMin) {
    float Factor = Value;
    if (range_type == "stepped") {
      Factor = (Value - FromMin) / (FromMax - FromMin);
      Factor = (Steps > 0) ? floor(Factor * (Steps + 1.0)) / Steps : 0.0;
    }
    else if (range_type == "smoothstep") {
      Factor = (FromMin > FromMax) ? 1.0 - smoothstep(FromMax, FromMin, Value) :
                                     smoothstep(FromMin, FromMax, Value);
    }
    else if (range_type == "smootherstep") {
      Factor = (FromMin > FromMax) ? 1.0 - smootherstep(FromMax, FromMin, Value) :
                                     smootherstep(FromMin, FromMax, Value);
    }
    else {
      Factor = (Value - FromMin) / (FromMax - FromMin);
    }
    Result = ToMin + Factor * (ToMax - ToMin);
  }
}