Gordonjcp
/
peacock
1
0
Fork 0
Code Issues 6 Pull Requests Packages Projects Releases Wiki Activity

integer envelope

This commit is contained in:
Gordon JC Pearce 2025-12-19 12:21:44 +00:00
parent 9b4f3a1be0
commit 05ece71acd
3 changed files with 19 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
plugin/module.cpp
View File

@ -26,6 +26,11 @@ Module::Module() {
void Module::run(Voice* voice) {
// run updates for module board
// FIXME break these out to the patch setter
a = attackTable[patchRam.env_a]; // attack time coeff looked up in table
d = decayTable[patchRam.env_d]; // decay time coeff looked up in table
r = decayTable[patchRam.env_r]; // release time coeff looked up in table
s = patchRam.env_s << 7; // scale 0x00-0x7f to 0x0000-0x3f80
// work out the "master" cutoff
vcfCutoff = patchRam.vcfFreq / 127.0f;
vcfCutoff += lfo * (patchRam.vcfLfo/127.0f);
@ -34,18 +39,17 @@ void Module::run(Voice* voice) {
for (uint32_t i = 0; i < NUM_VOICES; i++) {
switch (voice[i].envPhase) {
case 0: // release phase FIXME use an enum I guess
voice[i].env *= decayTable[patchRam.env_r] / 65536.0f; // "RC" decay to zero
voice[i].env = (voice[i].env * d) >> 16; // "RC" decay to zero
break;
case 1: // attack phase
voice[i].env += attackTable[patchRam.env_a] / 65536.0f; // linear attack to 1
voice[i].env += a; // linear attack to 0x3fff
break;
case 2:
float t = patchRam.env_s / 127.0f;
voice[i].env = (voice[i].env - t) * (decayTable[patchRam.env_d] / 65536.0f) + t;
voice[i].env = (((voice[i].env - s) * d) >>16 ) + s;
break;
}
if (voice[i].env > 1.0f) {
voice[i].env = 1.0f;
if (voice[i].env > 0x3fff) {
voice[i].env = 0x3fff;
voice[i].envPhase = 2; // flip to decay
}
// per voice we need to calculate the key follow amount and envelope amount

5
plugin/module.hpp
View File

@ -37,6 +37,9 @@ class Module {
// precomputed values for all voices
float pw, saw, square, sub;
// "internal state" values for patch parameters
uint16_t a, d, s, r;
struct {
uint8_t lfoRate = 0x30; // lookup value defaults to 0x0200
uint8_t lfoDelay = 0x00;
@ -66,7 +69,7 @@ class Voice {
void off();
void run(Module* m, float* buffer, uint32_t samples);
uint8_t envPhase = 0;
float env = 0; // output amplitude
int16_t env = 0; // output amplitude
private:
float omega = 0, theta = 0; // phase increment and angle

6
plugin/voice.cpp
View File

@ -51,13 +51,15 @@ void Voice::run(Module* m, float* buffer, uint32_t samples) {
// carry out per-voice calculations for each block of samples
float out, t, fb, res;
float cut = 0.00513 + 0.075*env;
float cut = 0.00513 + 0.0000075*env;
// printf("%f ", delay);
m->saw = 1;
m->square = 1;
m->sub = .5;
m->pw = 0.5;
float amp = env / 4096.0f;
for (uint32_t i = 0; i < samples; i++) {
out = delay;
delay = 0;
@ -106,7 +108,7 @@ void Voice::run(Module* m, float* buffer, uint32_t samples) {
b4 = ((b3 - b4) * cut) + b4;
}
buffer[i] += 0.125 * env * b4;
buffer[i] += 0.125 * amp * b4;
lastpw = m->pw;
}
// buffer[0] += 1;