Rack/plugins/community/repos/FrozenWasteland/eurorack/stmlib/dsp/polyblep.h

// Copyright 2017 Olivier Gillet.
//
// Author: Olivier Gillet (ol.gillet@gmail.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// 
// See http://creativecommons.org/licenses/MIT/ for more information.
//
// -----------------------------------------------------------------------------
//
// Polynomial approximation of band-limited step for band-limited waveform
// synthesis.

#ifndef STMLIB_DSP_POLYBLEP_H_
#define STMLIB_DSP_POLYBLEP_H_

#include "stmlib/stmlib.h"

namespace stmlib {

inline float ThisBlepSample(float t) {
  return 0.5f * t * t;
}

inline float NextBlepSample(float t) {
  t = 1.0f - t;
  return -0.5f * t * t;
}

inline float NextIntegratedBlepSample(float t) {
  const float t1 = 0.5f * t;
  const float t2 = t1 * t1;
  const float t4 = t2 * t2;
  return 0.1875f - t1 + 1.5f * t2 - t4;
}

inline float ThisIntegratedBlepSample(float t) {
  return NextIntegratedBlepSample(1.0f - t);
}
  
}  // namespace stmlib

#endif  // STMLIB_DSP_POLYBLEP_H_