trnr/tlib
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

initial commit

Browse Source
This commit is contained in:
Christopher Herb
2023-07-07 10:07:53 +02:00
commit ad8c3fbe74
18 changed files with 3554 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

280
synth/tx_envelope.h Normal file
View File

@@ -0,0 +1,280 @@
#pragma once
#include <array>
namespace trnr::lib::synth {
enum env_state {
idle = 0,
attack1,
attack2,
hold,
decay1,
decay2,
sustain,
release1,
release2
};
class tx_envelope {
public:
float attack1_rate;
float attack1_level;
float attack2_rate;
float hold_rate;
float decay1_rate;
float decay1_level;
float decay2_rate;
float sustain_level;
float release1_rate;
float release1_level;
float release2_rate;
tx_envelope(double _samplerate)
: samplerate { _samplerate }
, attack1_rate { 0 }
, attack1_level { 0 }
, attack2_rate { 0 }
, hold_rate { 0 }
, decay1_rate { 0 }
, decay1_level { 0 }
, decay2_rate { 0 }
, sustain_level { 0 }
, release1_rate { 0 }
, release1_level { 0 }
, release2_rate { 0 }
, level { 0.f }
, phase { 0 }
, state { idle }
, start_level { 0.f }
, h1 { 0. }
, h2 { 0. }
, h3 { 0. }
{
}
float process_sample(bool gate, bool trigger) {
int attack_mid_x1 = ms_to_samples(attack1_rate);
int attack_mid_x2 = ms_to_samples(attack2_rate);
int hold_samp = ms_to_samples(hold_rate);
int decay_mid_x1 = ms_to_samples(decay1_rate);
int decay_mid_x2 = ms_to_samples(decay2_rate);
int release_mid_x1 = ms_to_samples(release1_rate);
int release_mid_x2 = ms_to_samples(release2_rate);
// if note on is triggered, transition to attack phase
if (trigger) {
start_level = level;
phase = 0;
state = attack1;
}
// attack 1st half
if (state == attack1) {
// while in attack phase
if (phase < attack_mid_x1) {
level = lerp(0, start_level, attack_mid_x1, attack1_level, phase);
phase += 1;
}
// reset phase if parameter was changed
if (phase > attack_mid_x1) {
phase = attack_mid_x1;
}
// if attack phase is done, transition to decay phase
if (phase == attack_mid_x1) {
state = attack2;
phase = 0;
}
}
// attack 2nd half
if (state == attack2) {
// while in attack phase
if (phase < attack_mid_x2) {
level = lerp(0, attack1_level, attack_mid_x2, 1, phase);
phase += 1;
}
// reset phase if parameter was changed
if (phase > attack_mid_x2) {
phase = attack_mid_x2;
}
// if attack phase is done, transition to decay phase
if (phase == attack_mid_x2) {
state = hold;
phase = 0;
}
}
// hold
if (state == hold) {
if (phase < hold_samp) {
level = 1.0;
phase += 1;
}
if (phase > hold_samp) {
phase = hold_samp;
}
if (phase == hold_samp) {
state = decay1;
phase = 0;
}
}
// decay 1st half
if (state == decay1) {
// while in decay phase
if (phase < decay_mid_x1) {
level = lerp(0, 1, decay_mid_x1, decay1_level, phase);
phase += 1;
}
// reset phase if parameter was changed
if (phase > decay_mid_x1) {
phase = decay_mid_x1;
}
// if decay phase is done, transition to sustain phase
if (phase == decay_mid_x1) {
state = decay2;
phase = 0;
}
}
// decay 2nd half
if (state == decay2) {
// while in decay phase
if (phase < decay_mid_x2) {
level = lerp(0, decay1_level, decay_mid_x2, sustain_level, phase);
phase += 1;
}
// reset phase if parameter was changed
if (phase > decay_mid_x2) {
phase = decay_mid_x2;
}
// if decay phase is done, transition to sustain phase
if (phase == decay_mid_x2) {
state = sustain;
phase = 0;
level = sustain_level;
}
}
// while sustain phase: if note off is triggered, transition to release phase
if (state == sustain && !gate) {
state = release1;
level = sustain_level;
}
// release 1st half
if (state == release1) {
// while in release phase
if (phase < release_mid_x1) {
level = lerp(0, sustain_level, release_mid_x1, release1_level, phase);
phase += 1;
}
// reset phase if parameter was changed
if (phase > release_mid_x1) {
phase = release_mid_x1;
}
// transition to 2nd release half
if (phase == release_mid_x1) {
phase = 0;
state = release2;
}
}
// release 2nd half
if (state == release2) {
// while in release phase
if (phase < release_mid_x2) {
level = lerp(0, release1_level, release_mid_x2, 0, phase);
phase += 1;
}
// reset phase if parameter was changed
if (phase > release_mid_x2) {
phase = release_mid_x2;
}
// reset
if (phase == release_mid_x2) {
phase = 0;
state = idle;
level = 0;
}
}
return smooth(level);
}
bool is_busy() { return state != 0; }
void set_samplerate(double sampleRate) {
this->samplerate = sampleRate;
}
// returns the x/y coordinates of the envelope points as a list for graphical representation.
std::array<float, 18> calc_coordinates() {
float a_x = 0;
float a_y = 0;
float b_x = attack1_rate;
float b_y = attack1_level;
float c_x = b_x + attack2_rate;
float c_y = 1;
float d_x = c_x + hold_rate;
float d_y = 1;
float e_x = d_x + decay1_rate;
float e_y = decay1_level;
float f_x = e_x + decay2_rate;
float f_y = sustain_level;
float g_x = f_x + 125;
float g_y = sustain_level;
float h_x = g_x + release1_rate;
float h_y = release1_level;
float i_x = h_x + release2_rate;
float i_y = 0;
float total = i_x;
return {
a_x,
a_y,
b_x / total,
b_y,
c_x / total,
c_y,
d_x / total,
d_y,
e_x / total,
e_y,
f_x / total,
f_y,
g_x / total,
g_y,
h_x / total,
h_y,
i_x / total,
i_y
};
}
private:
double samplerate;
int phase;
float level;
env_state state;
float start_level;
float h1;
float h2;
float h3;
float lerp(float x1, float y1, float x2, float y2, float x) { return y1 + (((x - x1) * (y2 - y1)) / (x2 - x1)); }
float smooth(float sample) {
h3 = h2;
h2 = h1;
h1 = sample;
return (h1 + h2 + h3) / 3.f;
}
float ms_to_samples(float ms) { return ms * samplerate / 1000.f; }
};
}