text: //    Copyright 2021 Shaye Garg
  //
  //    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.
  
  #pragma once
  
  #include "Core/Math/Vector.h"
  
  Point ConcentricSampleDisk(const std::pair<float, float>& sample);
  
  Vector CosineSampleHemisphere(const std::pair<float, float>& sample);
  float CosineHemispherePdf(float cos);
  
  float PowerHeuristic(int nf, float fPdf, int ng, float gPdf);
  