StaircaseFunction.hh

// Copyright QED Software 2023.
 
#ifndef GRAIL_STEP_FUNCTION_H
#define GRAIL_STEP_FUNCTION_H
 
#include "Curve.hh"
 
namespace grail
{
namespace evaluator
{
 struct StepData
 {
 float value = 0.0f;
 float startPoint = 0.0f;
 bool inclusiveStartPoint = false;
 };
 
 template <typename ContextType>
 class StaircaseFunction final : public Curve<ContextType>
 {
 public:
 StaircaseFunction(std::shared_ptr<Evaluator<ContextType>> childEvaluator,
 const std::vector<StepData>& data)
 : Curve<ContextType>{childEvaluator}, data{data}
 {
 #ifndef NDEBUG
 assert(data.size() >= 1);
 float previousX = data[0].startPoint;
 for(size_t i = 1; i < data.size(); ++i)
 {
 assert(previousX < data[i].startPoint);
 previousX = data[i].startPoint;
 }
 #endif //NDEBUG
 }
 
 virtual float Sample(float argument) const override final
 {
 for(std::size_t i = data.size() - 1; i > 0; --i)
 {
 if(argument > data[i].startPoint || (argument == data[i].startPoint && data[i].inclusiveStartPoint))
 {
 return data[i].value;
 }
 }
 return data[0].value;
 }
 
 std::vector<StepData>& GetData() { return data; }
 const std::vector<StepData>& GetData() const { return data; }
 
 virtual data::EvaluatorType GetEvaluatorType() const override final { return data::EvaluatorType::CURVE_STAIRCASE; }
 
 private:
 std::vector<StepData> data{};
 };
}
}
#endif // GRAIL_STEP_FUNCTION_H