// Copyright 2012 Olivier Gillet.
//
// Author: Olivier Gillet (ol.gillet@gmail.com)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see .
#ifndef BRAIDS_ENVELOPE_H_
#define BRAIDS_ENVELOPE_H_
#include "stmlib/stmlib.h"
#include "stmlib/utils/dsp.h"
#include "braids/resources.h"
namespace braids {
using namespace stmlib;
enum EnvelopeSegment {
ENV_SEGMENT_ATTACK = 0,
ENV_SEGMENT_DECAY = 1,
ENV_SEGMENT_DEAD = 2,
ENV_NUM_SEGMENTS,
};
class Envelope {
public:
Envelope() { }
~Envelope() { }
void Init() {
target_[ENV_SEGMENT_ATTACK] = 65535;
target_[ENV_SEGMENT_DECAY] = 0;
target_[ENV_SEGMENT_DEAD] = 0;
increment_[ENV_SEGMENT_DEAD] = 0;
}
inline EnvelopeSegment segment() const {
return static_cast(segment_);
}
inline void Update(int32_t a, int32_t d) {
increment_[ENV_SEGMENT_ATTACK] = lut_env_portamento_increments[a];
increment_[ENV_SEGMENT_DECAY] = lut_env_portamento_increments[d];
}
inline void Trigger(EnvelopeSegment segment) {
if (segment == ENV_SEGMENT_DEAD) {
value_ = 0;
}
a_ = value_;
b_ = target_[segment];
segment_ = segment;
phase_ = 0;
}
inline uint16_t Render() {
uint32_t increment = increment_[segment_];
phase_ += increment;
if (phase_ < increment) {
value_ = Mix(a_, b_, 65535);
Trigger(static_cast(segment_ + 1));
}
if (increment_[segment_]) {
value_ = Mix(a_, b_, Interpolate824(lut_env_expo, phase_));
}
return value_;
}
inline uint16_t value() const { return value_; }
private:
// Phase increments for each segment.
uint32_t increment_[ENV_NUM_SEGMENTS];
// Value that needs to be reached at the end of each segment.
uint16_t target_[ENV_NUM_SEGMENTS];
// Current segment.
size_t segment_;
// Start and end value of the current segment.
uint16_t a_;
uint16_t b_;
uint16_t value_;
uint32_t phase_;
DISALLOW_COPY_AND_ASSIGN(Envelope);
};
} // namespace braids
#endif // BRAIDS_ENVELOPE_H_