CurveConversion.hpp

#pragma once
#include <Curve/Segment/Linear/LinearSegment.hpp>
#include <Curve/Segment/Power/PowerSegment.hpp>
 
#include <ossia/editor/curve/curve.hpp>
 
namespace Engine
{
namespace score_to_ossia
{
 
template <typename Y_T>
struct CurveTraits;
 
template <>
struct CurveTraits<int>
{
  static const constexpr auto fun = &Curve::SegmentModel::makeIntFunction;
  static const constexpr auto scaled = &Curve::SegmentModel::makeScaledIntFunction;
};
 
template <>
struct CurveTraits<float>
{
  static const constexpr auto fun = &Curve::SegmentModel::makeFloatFunction;
  static const constexpr auto scaled = &Curve::SegmentModel::makeScaledFloatFunction;
};
 
template <>
struct CurveTraits<double>
{
  static const constexpr auto fun = &Curve::SegmentModel::makeDoubleFunction;
  static const constexpr auto scaled = &Curve::SegmentModel::makeScaledDoubleFunction;
};
 
template <
    typename X_T, typename Y_T, typename XScaleFun, typename YScaleFun,
    typename Segments>
std::shared_ptr<ossia::curve<X_T, Y_T>> curve(
    XScaleFun scale_x, YScaleFun scale_y, const Segments& segments,
    const std::optional<ossia::destination>& tween)
{
  auto curve = std::make_shared<ossia::curve<X_T, Y_T>>();
  curve->reserve(segments.size() + 1);
 
  // Where the curve begins, wherever that is. The first segment is not
  // required to start at 0: leaving x0/y0 at their defaults there made the
  // ossia curve ramp from (0, 0) to the first segment's end, which throws that
  // segment away and shifts everything after it.
  auto start = segments[0]->start();
  curve->set_x0(scale_x(start.x()));
  curve->set_y0(scale_y(start.y()));
 
  // scale_y is affine: sampled segments are given it as offset and factor.
  const double offset = scale_y(0.);
  const double factor = double(scale_y(1.)) - offset;
  for(const auto& score_segment : segments)
  {
    auto end = score_segment->end();
    curve->add_point(
        (score_segment->*CurveTraits<Y_T>::scaled)(offset, factor), scale_x(end.x()),
        scale_y(end.y()));
  }
 
  if(tween)
  {
    curve->set_y0_destination(*tween);
  }
 
  return curve;
}
 
// Simpler curve, between [0; 1]
template <typename Segments>
ossia::curve<double, float>
floatCurve(const Segments& segments, const std::optional<ossia::destination>& tween)
{
  ossia::curve<double, float> curve;
 
  // See above: the first segment need not start at 0.
  auto start = segments[0]->start();
  curve.set_x0(start.x());
  curve.set_y0(start.y());
 
  for(const auto& score_segment : segments)
  {
    auto end = score_segment->end();
    curve.add_point(
        (score_segment->*CurveTraits<float>::scaled)(0., 1.), end.x(), end.y());
  }
 
  if(tween)
  {
    curve.set_y0_destination(*tween);
  }
 
  return curve;
}
 
}
}