commit aae63c815150bb7cd4535991b42d669404879d24
parent 613658446bf6744a64b4436a744bc4c25af56a3c
Author: friedolino78 <[email protected]>
Date: Sun, 16 Feb 2025 04:11:34 +0100
New chorus mode: "Roland Ensemble" (#274)
Diffstat:
6 files changed, 212 insertions(+), 70 deletions(-)
diff --git a/doc/effects.txt b/doc/effects.txt
@@ -137,6 +137,10 @@ with very short LFO delay and little LFO depth. You can imagine a flanger as two
copies of a sound playing at almost the same time. This leads to interference,
which can be clearly heard. It is popular to apply flangers to guitars, giving
them more "character".
+While in standard CHORUS and FLANGER mode there is only one additional voice that
+can be blended with the original one using the amount knob, the DUAL and TRIPLE
+mode adds two/three voices with their LFOs each being phase shifted by 180 / 120 degrees.
+Those have been used by famous roland string synthesizers.
Usage
^^^^^
@@ -153,6 +157,7 @@ the *D/W* knob, but we have not applied panning and subtraction yet.
* Next, the signal can be negated. If the *Subtract* checkbox is activated,
the amplitude is multiplied by -1.
* Finally, *Pan* lets you apply panning.
+* *Mode* selector lets you choose between Chorus, Flanger, Dual- and Triple Chorus.
Distortion
~~~~~~~~~~
diff --git a/src/Effects/Chorus.cpp b/src/Effects/Chorus.cpp
@@ -21,6 +21,10 @@ using namespace std;
namespace zyn {
+constexpr float PHASE_120 = 0.33333333f;
+constexpr float PHASE_180 = 0.5f;
+constexpr float PHASE_240 = 0.66666666f;
+
#define rObject Chorus
#define rBegin [](const char *msg, rtosc::RtData &d) {
#define rEnd }
@@ -28,7 +32,8 @@ namespace zyn {
rtosc::Ports Chorus::ports = {
{"preset::i", rProp(parameter)
rOptions(Chorus1, Chorus2, Chorus3, Celeste1, Celeste2,
- Flange1, Flange2, Flange3, Flange4, Flange5)
+ Flange1, Flange2, Flange3, Flange4, Flange5,
+ Triple, Dual)
rProp(alias)
rDefault(0)
rDoc("Instrument Presets"), 0,
@@ -63,8 +68,8 @@ rtosc::Ports Chorus::ports = {
rPresets(64, 64, 90, 90, 31, 62, 109, 54, 97, 17), "Feedback"),
rEffPar(Plrcross, 9, rShort("l/r"), rPresets(119, 19, 127, 127, 127),
rDefault(0), "Left/Right Crossover"),
- rEffParTF(Pflangemode, 10, rShort("flange"), rDefault(false),
- "Flange Mode"),
+ rEffParOpt(Pflangemode, 10, rShort("mode"), rDefault(CHORUS),rOptions(CHORUS_MODES),
+ "Chorus Mode"),
rEffParTF(Poutsub, 11, rShort("sub"),
rPreset(4, true), rPreset(7, true), rPreset(9, true),
rDefault(false), "Output Subtraction"),
@@ -84,8 +89,8 @@ Chorus::Chorus(EffectParams pars)
setpreset(Ppreset);
changepar(1, 64);
lfo.effectlfoout(&lfol, &lfor);
- dl2 = getdelay(lfol);
- dr2 = getdelay(lfor);
+ dlNew = getdelay(lfol);
+ drNew = getdelay(lfor);
cleanup();
}
@@ -99,7 +104,7 @@ Chorus::~Chorus()
float Chorus::getdelay(float xlfo)
{
float result =
- (Pflangemode) ? 0 : (delay + xlfo * depth) * samplerate_f;
+ (Pflangemode==FLANGE) ? 0 : (delay + xlfo * depth) * samplerate_f;
//check if delay is too big (caused by bad setdelay() and setdepth()
if((result + 0.5f) >= maxdelay) {
@@ -112,15 +117,57 @@ float Chorus::getdelay(float xlfo)
return result;
}
+// sample
+
+inline float Chorus::getSample(float* delayline, float mdel, int dk)
+{
+ float samplePos = dk - mdel + float(maxdelay * 2); //where should I get the sample from
+ return cinterpolate(delayline, maxdelay, samplePos);
+
+}
+
//Apply the effect
void Chorus::out(const Stereo<float *> &input)
{
- dl1 = dl2;
- dr1 = dr2;
+ // store old delay value for linear interpolation
+ dlHist = dlNew;
+ drHist = drNew;
+ // calculate new lfo values
lfo.effectlfoout(&lfol, &lfor);
+ // calculate new delay values
+ dlNew = getdelay(lfol);
+ drNew = getdelay(lfor);
+ float fbComp = fb;
+ if (Pflangemode == DUAL) // ensemble mode
+ {
+ // same for second member for ensemble mode with 180° phase offset
+ dlHist2 = dlNew2;
+ drHist2 = drNew2;
+ lfo.effectlfoout(&lfol, &lfor, PHASE_180);
+ dlNew2 = getdelay(lfol);
+ drNew2 = getdelay(lfor);
+ fbComp /= 2.0f;
+ }
- dl2 = getdelay(lfol);
- dr2 = getdelay(lfor);
+ if (Pflangemode == TRIPLE) // ensemble mode
+ {
+ // same for second member for ensemble mode with 120° phase offset
+ dlHist2 = dlNew2;
+ drHist2 = drNew2;
+ lfo.effectlfoout(&lfol, &lfor, PHASE_120);
+ dlNew2 = getdelay(lfol);
+ drNew2 = getdelay(lfor);
+
+ // same for third member for ensemble mode with 240° phase offset
+ dlHist3 = dlNew3;
+ drHist3 = drNew3;
+ lfo.effectlfoout(&lfol, &lfor, PHASE_240);
+ dlNew3 = getdelay(lfol);
+ drNew3 = getdelay(lfor);
+ // reduce amplitude to match single phase modes
+ // 0.85 * fbComp / 3
+ fbComp /= 3.53f;
+ }
for(int i = 0; i < buffersize; ++i) {
float inL = input.l[i];
@@ -131,41 +178,67 @@ void Chorus::out(const Stereo<float *> &input)
inR = tmpc.r * (1.0f - lrcross) + tmpc.l * lrcross;
//Left channel
-
- //compute the delay in samples using linear interpolation between the lfo delays
- float mdel =
- (dl1 * (buffersize - i) + dl2 * i) / buffersize_f;
+ // reset output accumulator
+ output = 0.0f;
+ // increase delay line writing position and handle turnaround
if(++dlk >= maxdelay)
dlk = 0;
- float tmp = dlk - mdel + maxdelay * 2.0f; //where should I get the sample from
-
- dlhi = (int) tmp;
- dlhi %= maxdelay;
-
- float dlhi2 = (dlhi - 1 + maxdelay) % maxdelay;
- float dllo = 1.0f + floorf(tmp) - tmp;
- efxoutl[i] = cinterpolate(delaySample.l, maxdelay, dlhi2) * dllo
- + cinterpolate(delaySample.l, maxdelay,
- dlhi) * (1.0f - dllo);
- delaySample.l[dlk] = inL + efxoutl[i] * fb;
+ // linear interpolate from old to new value over length of the buffer
+ float dl = (dlHist * (buffersize - i) + dlNew * i) / buffersize_f;
+ // get sample with that delay from delay line and add to output accumulator
+ output += getSample(delaySample.l, dl, dlk);
+ switch (Pflangemode) {
+ case DUAL:
+ // calculate and apply delay for second ensemble member
+ dl = (dlHist2 * (buffersize - i) + dlNew2 * i) / buffersize_f;
+ output += getSample(delaySample.l, dl, dlk);
+ break;
+ case TRIPLE:
+ // calculate and apply delay for second ensemble member
+ dl = (dlHist2 * (buffersize - i) + dlNew2 * i) / buffersize_f;
+ output += getSample(delaySample.l, dl, dlk);
+ // same for third ensemble member
+ dl = (dlHist3 * (buffersize - i) + dlNew3 * i) / buffersize_f;
+ output += getSample(delaySample.l, dl, dlk);
+ break;
+ default:
+ // nothing to do for standard chorus
+ break;
+ }
+ // store current input + feedback to delay line at writing position
+ delaySample.l[dlk] = inL + output * fbComp;
+ // write output to output interface
+ efxoutl[i] = output;
//Right channel
-
- //compute the delay in samples using linear interpolation between the lfo delays
- mdel = (dr1 * (buffersize - i) + dr2 * i) / buffersize_f;
+ output = 0.0f;
if(++drk >= maxdelay)
drk = 0;
- tmp = drk * 1.0f - mdel + maxdelay * 2.0f; //where should I get the sample from
-
- dlhi = (int) tmp;
- dlhi %= maxdelay;
+ float dr = (drHist * (buffersize - i) + drNew * i) / buffersize_f;
+ output += getSample(delaySample.r, dr, drk);
+ switch (Pflangemode) {
+ case DUAL:
+ // calculate and apply delay for second ensemble member
+ dr = (drHist2 * (buffersize - i) + drNew2 * i) / buffersize_f;
+ output += getSample(delaySample.r, dr, drk);
+ break;
+ case TRIPLE:
+ // calculate and apply delay for second ensemble member
+ dr = (drHist2 * (buffersize - i) + drNew2 * i) / buffersize_f;
+ output += getSample(delaySample.r, dr, drk);
+ // same for third ensemble member
+ dr = (drHist3 * (buffersize - i) + drNew3 * i) / buffersize_f;
+ output += getSample(delaySample.r, dr, drk);
+ // reduce amplitude to match single phase modes
+ output *= 0.85f;
+ break;
+ default:
+ // nothing to do for standard chorus
+ break;
+ }
- dlhi2 = (dlhi - 1 + maxdelay) % maxdelay;
- dllo = 1.0f + floorf(tmp) - tmp;
- efxoutr[i] = cinterpolate(delaySample.r, maxdelay, dlhi2) * dllo
- + cinterpolate(delaySample.r, maxdelay,
- dlhi) * (1.0f - dllo);
- delaySample.r[dlk] = inR + efxoutr[i] * fb;
+ delaySample.r[drk] = inR + output * fbComp;
+ efxoutr[i] = output;
}
if(Poutsub)
@@ -216,7 +289,7 @@ void Chorus::setvolume(unsigned char _Pvolume)
unsigned char Chorus::getpresetpar(unsigned char npreset, unsigned int npar)
{
#define PRESET_SIZE 12
-#define NUM_PRESETS 10
+#define NUM_PRESETS 12
static const unsigned char presets[NUM_PRESETS][PRESET_SIZE] = {
//Chorus1
{64, 64, 50, 0, 0, 90, 40, 85, 64, 119, 0, 0},
@@ -237,7 +310,11 @@ unsigned char Chorus::getpresetpar(unsigned char npreset, unsigned int npar)
//Flange4
{64, 64, 40, 0, 1, 62, 12, 19, 97, 0, 0, 0},
//Flange5
- {64, 64, 55, 105, 0, 24, 39, 19, 17, 0, 0, 1}
+ {64, 64, 55, 105, 0, 24, 39, 19, 17, 0, 0, 1},
+ //Ensemble
+ {127, 64, 68, 25, 1, 24, 35, 55, 64, 0, TRIPLE, 0},
+ //Dual
+ {127, 64, 55, 25, 1, 24, 32, 55, 80, 0, DUAL, 0}
};
if(npreset < NUM_PRESETS && npar < PRESET_SIZE) {
return presets[npreset][npar];
@@ -292,7 +369,8 @@ void Chorus::changepar(int npar, unsigned char value)
setlrcross(value);
break;
case 10:
- Pflangemode = (value > 1) ? 1 : value;
+ lfo.updateparams();
+ Pflangemode = (value > 3) ? 3 : value;
break;
case 11:
Poutsub = (value > 1) ? 1 : value;
diff --git a/src/Effects/Chorus.h b/src/Effects/Chorus.h
@@ -17,10 +17,30 @@
#include "EffectLFO.h"
#include "../Misc/Stereo.h"
-#define MAX_CHORUS_DELAY 250.0f //ms
+
+
+
namespace zyn {
+#define MAX_CHORUS_DELAY 250.0f //ms
+
+// Chorus modes
+// CHORUS default chorus mode
+// FLANGE flanger mode (very short delays)
+// TRIPLE 120° triple phase chorus
+// DUAL 180° dual phase chorus
+
+#define CHORUS_MODES \
+ CHORUS,\
+ FLANGE,\
+ TRIPLE,\
+ DUAL
+
+enum {
+ CHORUS_MODES
+};
+
/**Chorus and Flange effects*/
class Chorus final:public Effect
{
@@ -73,12 +93,14 @@ class Chorus final:public Effect
static rtosc::Ports ports;
private:
+ inline float getSample(float* delayline, float mdel, int dk);
+
//Chorus Parameters
unsigned char Pvolume;
unsigned char Pdepth; //the depth of the Chorus(ms)
unsigned char Pdelay; //the delay (ms)
unsigned char Pfb; //feedback
- unsigned char Pflangemode; //how the LFO is scaled, to result chorus or flange
+ unsigned char Pflangemode; //mode as described above in CHORUS_MODES
unsigned char Poutsub; //if I wish to subtract the output instead of the adding it
EffectLFO lfo; //lfo-ul chorus
@@ -91,11 +113,18 @@ class Chorus final:public Effect
//Internal Values
float depth, delay, fb;
- float dl1, dl2, dr1, dr2, lfol, lfor;
+ float dlHist, dlNew, lfol;
+ float drHist, drNew, lfor;
+ float dlHist2, dlNew2;
+ float drHist2, drNew2;
+ float dlHist3, dlNew3;
+ float drHist3, drNew3;
int maxdelay;
Stereo<float *> delaySample;
- int dlk, drk, dlhi;
+ int dlk, drk;
float getdelay(float xlfo);
+
+ float output;
};
}
diff --git a/src/Effects/EffectLFO.cpp b/src/Effects/EffectLFO.cpp
@@ -62,6 +62,7 @@ void EffectLFO::updateparams(void)
//Compute the shape of the LFO
float EffectLFO::getlfoshape(float x)
{
+ x = fmodf(x, 1.0f);
float out;
switch(lfotype) {
case 1: //EffectLFO_TRIANGLE
@@ -81,31 +82,40 @@ float EffectLFO::getlfoshape(float x)
}
//LFO output
-void EffectLFO::effectlfoout(float *outl, float *outr)
+void EffectLFO::effectlfoout(float *outl, float *outr, float phaseOffset)
{
float out;
-
- out = getlfoshape(xl);
+ // left stereo signal
+ out = getlfoshape(xl+phaseOffset);
if((lfotype == 0) || (lfotype == 1))
out *= (ampl1 + xl * (ampl2 - ampl1));
- xl += incx;
- if(xl > 1.0f) {
- xl -= 1.0f;
- ampl1 = ampl2;
- ampl2 = (1.0f - lfornd) + lfornd * RND;
- }
*outl = (out + 1.0f) * 0.5f;
+ // update left phase for master lfo
+ if(phaseOffset==0.0f) {
+ xl += incx;
+ if(xl > 1.0f) {
+ xl -= 1.0f;
+ ampl1 = ampl2;
+ ampl2 = (1.0f - lfornd) + lfornd * RND;
+ }
+ }
- out = getlfoshape(xr);
+ // right stereo signal
+ out = getlfoshape(xr+phaseOffset);
if((lfotype == 0) || (lfotype == 1))
out *= (ampr1 + xr * (ampr2 - ampr1));
- xr += incx;
- if(xr > 1.0f) {
- xr -= 1.0f;
- ampr1 = ampr2;
- ampr2 = (1.0f - lfornd) + lfornd * RND;
- }
*outr = (out + 1.0f) * 0.5f;
+
+ // update right phase for master lfo
+ if(phaseOffset==0.0f) {
+ xr += incx;
+ if(xr > 1.0f) {
+ xr -= 1.0f;
+ ampr1 = ampr2;
+ ampr2 = (1.0f - lfornd) + lfornd * RND;
+ }
+ }
+
}
}
diff --git a/src/Effects/EffectLFO.h b/src/Effects/EffectLFO.h
@@ -37,13 +37,16 @@ class EffectLFO
*/
~EffectLFO();
+ // if phaseOffset!=0 we don't want to update the phase but get a phased shifted output of the last one.
/**
- * Processes the LFO and outputs the result to the provided pointers.
- *
+ * calculate the output of the effect LFO for two signals (stereo)
* @param outl Pointer to the left output channel.
* @param outr Pointer to the right output channel.
+ * @param phaseOffset phaseoffset
+ * if phaseOffset is not 0 we don't want to update the phase
+ * but get the phased shifted output of the last one.
*/
- void effectlfoout(float *outl, float *outr);
+ void effectlfoout(float *outl, float *outr, float phaseOffset = 0.0f);
/**
* Updates the LFO parameters based on the current settings.
diff --git a/src/UI/EffUI.fl b/src/UI/EffUI.fl
@@ -442,12 +442,6 @@ if (filterwindow!=NULL){
code0 {o->init("parameter9");}
class Fl_Osc_Dial
}
- Fl_Check_Button {} {
- label Flange
- xywh {120 10 55 20} box THIN_UP_BOX down_box DOWN_BOX color 230 labelfont 1 labelsize 10 hide deactivate
- code0 {o->init("parameter10");}
- class Fl_Osc_Check
- }
Fl_Check_Button chorusp11 {
label Subtract
tooltip {inverts the output} xywh {185 10 70 20} box THIN_UP_BOX down_box DOWN_BOX color 51 labelsize 10
@@ -469,6 +463,29 @@ if (filterwindow!=NULL){
xywh {25 25 100 20} labelfont 1 labelsize 10
}
}
+ Fl_Choice chorusp10 {
+ label {Mode}
+ tooltip {LFO function} xywh {270 15 80 15} box UP_BOX down_box BORDER_BOX labelfont 1 labelsize 10 align 5 textsize 8
+ code0 {o->init("parameter10");}
+ class Fl_Osc_Choice
+ } {
+ MenuItem {} {
+ label CHORUS
+ xywh {15 15 100 20} labelfont 1 labelsize 10
+ }
+ MenuItem {} {
+ label FLANGE
+ xywh {25 25 100 20} labelfont 1 labelsize 10
+ }
+ MenuItem {} {
+ label TRIPLE
+ xywh {35 35 100 20} labelfont 1 labelsize 10
+ }
+ MenuItem {} {
+ label DUAL
+ xywh {45 45 100 20} labelfont 1 labelsize 10
+ }
+ }
}
}
Function {make_phaser_window()} {} {
