New MIDI controllers, better ADSR algo, polyphony bugfixes

CMakeLists.txt

@@ -4,23 +4,34 @@ project(synth)
 set(CMAKE_CXX_STANDARD 20)
 set(BUILD_SHARED_LIBS OFF)
 
-set(PA_USE_ASIO ON CACHE BOOL "Enable support for ASIO")
+if(WIN32)
+    option(PA_USE_ASIO "" ON)
+    option(PA_USE_WDMKS "" OFF)
+endif()
 add_subdirectory(lib/portaudio)
 add_subdirectory(lib/portmidi)
 add_subdirectory(lib/wxWidgets)
 
+if(MSVC)
+    add_compile_definitions(_USE_MATH_DEFINES)
+endif()
+
 add_executable(main
     src/synthapp.cpp
     src/synthframe.cpp
     src/synth/synth.cpp
     src/synth/voicemanager.cpp
     src/synth/part.cpp
+    src/synth/preset.cpp
     src/synth/voice.cpp
     src/synth/dsp/oscillator.cpp
     src/synth/dsp/filter.cpp
     src/synth/dsp/adsr.cpp)
 target_include_directories(main PRIVATE include)
 
+#target_compile_options(main PRIVATE -fsanitize=thread)
+#target_link_options(main PRIVATE -fsanitize=thread)
+
 target_link_libraries(main PRIVATE PortAudio)
 target_link_libraries(main PRIVATE portmidi)
 target_include_directories(main PRIVATE lib/portmidi/porttime)

include/synth/cc.h

@@ -13,5 +13,7 @@
 #define CC_AMP_DEC 75   // Decay Time
 #define CC_AMP_SUS 76   // Sustain
 #define CC_OSC_DET 94   // Detune (Standard MIDI)
- 
+#define CC_MOD_FLT 20   // Mod Envelope Filter Gain
+#define CC_KEY_TRK 21   // Filter Key Tracking
+
 #endif

include/synth/dsp/adsr.h

@@ -16,7 +16,7 @@ public:
 
     Envelope const * env;
 
-    ADSR() : state(IDLE), gain(0) {};
+    ADSR() : state(IDLE), t(0), last(0) {};
     void assign(Envelope const * env);
     void noteOn();
     void noteOff();
@@ -25,27 +25,29 @@ public:
     }
 
     inline float tick() {
-        float out = curve(gain);
-
         switch(state) {
             case IDLE:
-                break;
+                return 0;
 
             case ATTACK:
-                if(gain < 1) {
-                    gain += env->attackStep;
+                if(t < 1) {
+                    t += env->attackStep;
+                    last = curve(t);
                 } else {
                     state = DECAY;
-                    gain = 1;
+                    t = 1;
+                    last = 1;
                 }
                 break;
 
             case DECAY:
-                if(gain > env->sustain) {
-                    gain -= env->decayStep;
+                if(t > 0) {
+                    t -= env->decayStep;
+                    last = env->sustain + (1 - env->sustain) * curve(t);
                 } else {
                     state = SUSTAIN;
-                    gain = env->sustain;
+                    t = 1;
+                    last = env->sustain;
                 }
                 break;
 
@@ -53,21 +55,24 @@ public:
                 break;
 
             case RELEASE:
-                if(gain > 0) {
-                    gain -= env->releaseStep;
+                if(t > 0) {
+                    t -= env->releaseStep;
+                    return last * curve(t);
                 } else {
                     state = IDLE;
-                    gain = 0;
+                    t = 0;
+                    last = 0;
                 }
                 break;
         }
 
-        return out;
+        return last;
     }
 
 private:
     enum { IDLE, ATTACK, DECAY, SUSTAIN, RELEASE } state;
-    float gain;
+    float t;
+    float last;
 
     float curve(float gain) {
         return 0.5 - 0.5 * cos(clamp(gain * M_PI, 0, M_PI));

include/synth/dsp/filter.h

@@ -70,8 +70,8 @@ private:
 public:
     void assign(Settings const * settings);
     
-    inline float tick(float as, float freqMod) {
-        float freq = clamp(settings->freq + freqMod, 0, 1);
+    inline float tick(float as, float freqAdd, float freqScale) {
+        float freq = clamp(freqScale * settings->freq + freqAdd, 0, 1);
         float Q = fmaxf(0.1, settings->Q);
 
         SVF12::Output in = first.tick(as, freq, Q);

include/synth/dsp/oscillator.h

@@ -5,6 +5,7 @@
  * Further info about BLEP at: https://pbat.ch/sndkit/blep/ 
  */
 
+#include <cstdlib>
 #include <math.h>
 
 #define PIx2 (2 * M_PI)

include/synth/part.h

@@ -2,7 +2,7 @@
 #define __PART_H__
 
 #include <unordered_map>
-#include <unordered_set>
+#include <set>
 
 #include "globals.h"
 #include "voicemanager.h"
@@ -27,10 +27,8 @@ public:
         frame out{0};
         for(auto& kv : notes) {
             int note = kv.first;
-            const float osc1PhaseStep = noteToFreq(note - settings.oscDetune + pitchBend) * PIx2 / SAMPLE_RATE;
-            const float osc2PhaseStep = noteToFreq(note + settings.oscDetune + pitchBend) * PIx2 / SAMPLE_RATE;
             for(auto& voice : kv.second) {
-                out += voice->tick(osc1PhaseStep, osc2PhaseStep);
+                out += voice->tick(note, pitchBend, modulation);
             }
         }
         out *= volume;
@@ -41,7 +39,7 @@ private:
     float volume;
     float pitchBend;
     float modulation;
-    std::unordered_map<uint8_t, std::unordered_set<Voice*>> notes;
+    std::unordered_map<uint8_t, std::set<Voice*>> notes;
 };
 
 #endif

include/synth/preset.h

@@ -26,35 +26,12 @@ struct Preset {
     } filter;
 
     Envelope ampEnv;
-    Envelope fltEnv;
-};
+    Envelope modEnv;
 
-static const Preset DEFAULT_PRESET = {
-    .osc1Mode = Oscillator::MODE_SAW,
-    .osc2Mode = Oscillator::MODE_SAW,
-    .oscMix = 64,
-    .oscDetune = 70,
-
-    .filter = {
-        .type = Filter::TYPE_LP,
-        .slope = Filter::SLOPE_24,
-        .freq = 0,
-        .Q = 22,
-    },
-
-    .ampEnv = {
-        .attack = 0,
-        .decay = 0,
-        .sustain = 127,
-        .release = 0
-    },
-
-    .fltEnv = {
-        .attack = 0,
-        .decay = 0,
-        .sustain = 127,
-        .release = 0
-    }
+    uint8_t modEnvFltGain;
+    uint8_t keyTrack;
 };
 
+extern const Preset DEFAULT_PRESET;
+
 #endif

include/synth/synth.h

@@ -22,7 +22,8 @@ public:
         for(auto& part : parts) {
             out += part.tick();
         }
-        return out * 0.125;
+        out *= 0.100;
+        return out;
     }
 
 private:

include/synth/voice.h

@@ -1,6 +1,7 @@
 #ifndef __VOICE_H__
 #define __VOICE_H__
 
+#include "globals.h"
 #include "preset.h"
 
 #include "dsp/oscillator.h"
@@ -18,29 +19,38 @@ public:
         float oscDetune;
 
         ADSR::Envelope ampEnv;
-        ADSR::Envelope fltEnv;
+        ADSR::Envelope modEnv;
+
+        float modEnvFltGain;
+        float keyTrack;
     } Settings;
 
 private:
     Settings const * settings;
 
     ADSR adsrAmp;
-    ADSR adsrFlt;
+    ADSR adsrMod;
     Oscillator osc1;
     Oscillator osc2;
     Filter filter;
 
 public:
+    bool keyed;
+
+    Voice(): keyed(false) {}
     void assign(Settings const * settings);
     void noteOn();
     void noteOff();
     bool isIdle() { return adsrAmp.isIdle(); }
 
-    inline float tick(float osc1PhaseStep, float osc2PhaseStep) {
+    inline float tick(int note, float pitchBend, float modulation) {
+        const float keyTrackMul = 1 + settings->keyTrack * noteToFreq(note + pitchBend) / 440.0;
+        const float osc1PhaseStep = noteToFreq(note - settings->oscDetune + pitchBend) * PIx2 / SAMPLE_RATE;
+        const float osc2PhaseStep = noteToFreq(note + settings->oscDetune + pitchBend) * PIx2 / SAMPLE_RATE;
         float out = 0;
         out += (1 - settings->oscMix) * osc1.tick(osc1PhaseStep);
         out +=      settings->oscMix  * osc2.tick(osc2PhaseStep);
-        out = filter.tick(out, adsrFlt.tick());
+        out = filter.tick(out, settings->modEnvFltGain * adsrMod.tick(), keyTrackMul);
         out *= adsrAmp.tick();
         return out;
     }

include/synthframe.h

@@ -18,13 +18,17 @@ private:
         AMP_SUSTAIN_SLIDER,
         AMP_RELEASE_SLIDER,
         
-        FLT_ATTACK_SLIDER,
-        FLT_DECAY_SLIDER,
-        FLT_SUSTAIN_SLIDER,
-        FLT_RELEASE_SLIDER,
+        MOD_ATTACK_SLIDER,
+        MOD_DECAY_SLIDER,
+        MOD_SUSTAIN_SLIDER,
+        MOD_RELEASE_SLIDER,
 
         FLT_FREQ_SLIDER,
-        FLT_Q_SLIDER
+        FLT_Q_SLIDER,
+
+        KEY_TRACK_SLIDER,
+
+        MOD_ENV_FLT_GAIN
     };
 
     void OnExit(wxCommandEvent& event);
@@ -33,6 +37,8 @@ private:
     void OnFltFreqScroll(wxScrollEvent& event);
     void OnFltQScroll(wxScrollEvent& event);
 
+    void OnKeyTrackScroll(wxScrollEvent& event);
+
     void OnAmpAttackScroll(wxScrollEvent& event);
     void OnAmpDecayScroll(wxScrollEvent& event);
     void OnAmpSustainScroll(wxScrollEvent& event);
@@ -43,6 +49,8 @@ private:
     void OnFltSustainScroll(wxScrollEvent& event);
     void OnFltReleaseScroll(wxScrollEvent& event);
 
+    void OnModEnvFltGainScroll(wxScrollEvent& event);
+
     wxDECLARE_EVENT_TABLE();
 };
 

src/synth/dsp/adsr.cpp

@@ -6,8 +6,10 @@ void ADSR::assign(Envelope const * env) {
 
 void ADSR::noteOn() {
     state = ATTACK;
+    t = 0;
 }
 
 void ADSR::noteOff() {
     state = RELEASE;
+    t = 1;
 }

src/synth/part.cpp

@@ -33,10 +33,13 @@ void Part::loadPreset(const Preset * preset) {
     settings.ampEnv.sustain = preset->ampEnv.sustain / 127.0;
     settings.ampEnv.releaseStep = timeToStep(ccToDR(preset->ampEnv.release));
 
-    settings.fltEnv.attackStep = timeToStep(ccToA(preset->fltEnv.attack));
-    settings.fltEnv.decayStep = timeToStep(ccToDR(preset->fltEnv.decay));
-    settings.fltEnv.sustain = preset->fltEnv.sustain / 127.0;
-    settings.fltEnv.releaseStep = timeToStep(ccToDR(preset->fltEnv.release));
+    settings.modEnv.attackStep = timeToStep(ccToA(preset->modEnv.attack));
+    settings.modEnv.decayStep = timeToStep(ccToDR(preset->modEnv.decay));
+    settings.modEnv.sustain = preset->modEnv.sustain / 127.0;
+    settings.modEnv.releaseStep = timeToStep(ccToDR(preset->modEnv.release));
+
+    settings.modEnvFltGain = preset->modEnvFltGain / 127.0;
+    settings.keyTrack = preset->keyTrack / 127.0;
 }
 
 void Part::noteOn(int note, int velocity) {
@@ -58,15 +61,19 @@ void Part::noteOn(int note, int velocity) {
     if(notes.count(note)) {
         notes.at(note).insert(voice);
     } else {
-        notes.emplace(note, std::unordered_set<Voice *>{voice});
+        notes.emplace(note, std::set<Voice *>{voice});
     }
 }
 
 void Part::noteOff(int note) {
     if(notes.count(note)) {
-        for(auto& voice : notes.at(note)) {
-            voice->noteOff();
-        }
+        auto& voices = notes.at(note);
+        for (auto i = voices.rbegin(); i != voices.rend(); ++i ) {
+            if((*i)->keyed) {
+                (*i)->noteOff();
+                break;
+            }
+        } 
     }
 }
 
@@ -77,19 +84,19 @@ void Part::control(int code, int value) {
             break;
 
         case CC_FLT_ATK: // Filter Attack Time
-            settings.fltEnv.attackStep = timeToStep(ccToA(value));
+            settings.modEnv.attackStep = timeToStep(ccToA(value));
             break;
         
         case CC_FLT_DEC: // Filter Decay Time
-            settings.fltEnv.decayStep = timeToStep(ccToDR(value));
+            settings.modEnv.decayStep = timeToStep(ccToDR(value));
             break;
 
         case CC_FLT_SUS: // Filter Sustain
-            settings.fltEnv.sustain = value / 127.0;
+            settings.modEnv.sustain = value / 127.0;
             break;
 
         case CC_FLT_REL: // Filter Release Time
-            settings.fltEnv.releaseStep = timeToStep(ccToDR(value));
+            settings.modEnv.releaseStep = timeToStep(ccToDR(value));
             break;
 
         case CC_FLT_Q: // Timbre / Harmonic Content (Standard MIDI)
@@ -120,5 +127,13 @@ void Part::control(int code, int value) {
         case CC_OSC_DET: // Detune (Standard MIDI)
             settings.oscDetune = (value - 64.0) / 100.0;
             break;
+
+        case CC_MOD_FLT: // Mod Envelope Filter Gain
+            settings.modEnvFltGain = value / 127.0;
+            break;
+
+        case CC_KEY_TRK: // Filter Key Tracking
+            settings.keyTrack = value / 127.0;
+            break;
     }
 }

src/synth/preset.cpp

@@ -0,0 +1,32 @@
+#include "synth/preset.h"
+
+const Preset DEFAULT_PRESET = {
+    .osc1Mode = Oscillator::MODE_SAW,
+    .osc2Mode = Oscillator::MODE_SAW,
+    .oscMix = 64,
+    .oscDetune = 70,
+
+    .filter = {
+        .type = Filter::TYPE_LP,
+        .slope = Filter::SLOPE_24,
+        .freq = 45,
+        .Q = 50,
+    },
+
+    .ampEnv = {
+        .attack = 0,
+        .decay = 80,
+        .sustain = 64,
+        .release = 64
+    },
+
+    .modEnv = {
+        .attack = 48,
+        .decay = 104,
+        .sustain = 0,
+        .release = 64
+    },
+
+    .modEnvFltGain = 40,
+    .keyTrack = 127
+};

src/synth/voice.cpp

@@ -3,18 +3,20 @@
 void Voice::assign(Settings const * settings) {
     this->settings = settings;
     adsrAmp.assign(&settings->ampEnv);
-    adsrFlt.assign(&settings->fltEnv);
+    adsrMod.assign(&settings->modEnv);
     osc1.assign(&settings->osc1Mode);
     osc2.assign(&settings->osc2Mode);
     filter.assign(&settings->filter);
 }
 
 void Voice::noteOn() {
+    keyed = true;
     adsrAmp.noteOn();
-    adsrFlt.noteOn();
+    adsrMod.noteOn();
 }
 
 void Voice::noteOff() {
+    keyed = false;
     adsrAmp.noteOff();
-    adsrFlt.noteOff();
+    adsrMod.noteOff();
 }

src/synth/voicemanager.cpp

@@ -1,3 +1,5 @@
+#include <iostream>
+
 #include "synth/voicemanager.h"
 
 VoiceManager::VoiceManager() {
@@ -10,6 +12,7 @@ Voice * VoiceManager::allocate() {
     int index = *idle.begin();
     idle.erase(index);
     active.insert(index);
+    std::cout << "allocate(): active=" << active.size() << " idle=" << idle.size() << std::endl;
     return &voices[index];
 }
 
@@ -17,4 +20,5 @@ void VoiceManager::free(Voice * voice) {
     int index = voice - voices;
     active.erase(index);
     idle.insert(index);
+    std::cout << "free(): active=" << active.size() << " idle=" << idle.size() << std::endl;
 }

src/synthapp.cpp

@@ -2,8 +2,6 @@
 #include <cmath>
 #include <iostream>
 
-#include <porttime.h>
-
 #include "synth/globals.h"
 
 #include "synthapp.h"
@@ -20,23 +18,10 @@ static int paCallback(
         PaStreamCallbackFlags statusFlags,
         void *userData ) {
     
-    Synth *synth = (Synth*) userData;
-    float *out = (float*) outputBuffer;
-
-    for(int i = 0; i < framesPerBuffer; i++) {
-        frame f = synth->tick();
-        *out++ = f.left;
-        *out++ = f.right;
-    }
-
-    return 0;
-}
+    SynthApp *app = (SynthApp*) userData;
 
-// PortTimer callback for MIDI I/O
-static void ptCallback(PtTimestamp timestamp, void* userData) {
-    SynthApp* synthApp = (SynthApp*) userData;
-    PmEvent events[8];
-    int numEvents = Pm_Read(synthApp->pmStream, events, 8);
+    PmEvent events[16];
+    int numEvents = Pm_Read(app->pmStream, events, 16);
     for(int i = 0; i < numEvents; ++i) {
         PmMessage msg = events[i].message;
 
@@ -45,15 +30,15 @@ static void ptCallback(PtTimestamp timestamp, void* userData) {
         
         if(type == 0x8 || (type == 0x9 && Pm_MessageData2(msg) == 0)) { // Note Off
             int note = Pm_MessageData1(msg);
-            synthApp->synth.noteOff(ch, note);
+            app->synth.noteOff(ch, note);
         } else if(type == 0x9) { // Note On
             int note = Pm_MessageData1(msg);
             int vel = Pm_MessageData2(msg);
-            synthApp->synth.noteOn(ch, note, vel);
+            app->synth.noteOn(ch, note, vel);
         } else if(type == 0xB) { // Controller Message
             int cc = Pm_MessageData1(msg);
             int val = Pm_MessageData2(msg);
-            synthApp->synth.control(ch, cc, val);
+            app->synth.control(ch, cc, val);
         }
         /*
         cout << "MIDI:";
@@ -63,10 +48,19 @@ static void ptCallback(PtTimestamp timestamp, void* userData) {
         cout << endl;
         */
     }
+
+    float *out = (float*) outputBuffer;
+
+    for(int i = 0; i < framesPerBuffer; i++) {
+        frame f = app->synth.tick();
+        *out++ = f.left;
+        *out++ = f.right;
+    }
+
+    return 0;
 }
 
 void handlePMError(PmError err) {
-    Pt_Stop();
     Pa_Terminate();
     Pm_Terminate();
     cerr << "PortMidi error" << endl;
@@ -76,7 +70,6 @@ void handlePMError(PmError err) {
 }
 
 void handlePAError(PaError err) {
-    Pt_Stop();
     Pa_Terminate();
     Pm_Terminate();
     cerr << "PortAudio error" << endl;
@@ -144,8 +137,7 @@ bool SynthApp::OnInit() {
         cout << "Invalid selection" << endl;   
     }
 
-    // Start MIDI timer and open MIDI input
-    Pt_Start(1, ptCallback, this);
+    // Open MIDI input
     PmError pmError = Pm_OpenInput(
         &pmStream,
         pmDeviceIndex,
@@ -172,7 +164,7 @@ bool SynthApp::OnInit() {
         0,                  // frames per buffer
         paNoFlag,
         paCallback,
-        &synth);
+        this);
     if(paErr != paNoError) {
         handlePAError(paErr);
     }
@@ -190,8 +182,6 @@ bool SynthApp::OnInit() {
 }
 
 int SynthApp::OnExit() {
-    Pt_Stop();
-
     PaError paErr = Pa_StopStream(paStream);
     if(paErr != paNoError) {
         handlePAError(paErr);

src/synthframe.cpp

@@ -1,6 +1,7 @@
 #include <iostream>
 
 #include "synth/cc.h"
+#include "synth/preset.h"
 
 #include "synthframe.h"
 #include "synthapp.h"
@@ -28,18 +29,22 @@ SynthFrame::SynthFrame() : wxFrame(NULL, wxID_ANY, "Hello World") {
     wxBoxSizer* sizer = new wxBoxSizer(wxHORIZONTAL);
     panel->SetSizer(sizer);
 
-    sizer->Add(new wxSlider(panel, FLT_FREQ_SLIDER, 0, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
-    sizer->Add(new wxSlider(panel, FLT_Q_SLIDER, 22, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, FLT_FREQ_SLIDER, DEFAULT_PRESET.filter.freq, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, FLT_Q_SLIDER, DEFAULT_PRESET.filter.Q, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
     sizer->AddSpacer(20);
-    sizer->Add(new wxSlider(panel, AMP_ATTACK_SLIDER, 0, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
-    sizer->Add(new wxSlider(panel, AMP_DECAY_SLIDER, 0, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
-    sizer->Add(new wxSlider(panel, AMP_SUSTAIN_SLIDER, 127, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
-    sizer->Add(new wxSlider(panel, AMP_RELEASE_SLIDER, 0, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, KEY_TRACK_SLIDER, DEFAULT_PRESET.keyTrack, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
     sizer->AddSpacer(20);
-    sizer->Add(new wxSlider(panel, FLT_ATTACK_SLIDER, 0, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
-    sizer->Add(new wxSlider(panel, FLT_DECAY_SLIDER, 0, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
-    sizer->Add(new wxSlider(panel, FLT_SUSTAIN_SLIDER, 127, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
-    sizer->Add(new wxSlider(panel, FLT_RELEASE_SLIDER, 0, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, AMP_ATTACK_SLIDER, DEFAULT_PRESET.ampEnv.attack, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, AMP_DECAY_SLIDER, DEFAULT_PRESET.ampEnv.decay, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, AMP_SUSTAIN_SLIDER, DEFAULT_PRESET.ampEnv.sustain, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, AMP_RELEASE_SLIDER, DEFAULT_PRESET.ampEnv.release, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->AddSpacer(20);
+    sizer->Add(new wxSlider(panel, MOD_ATTACK_SLIDER, DEFAULT_PRESET.modEnv.attack, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, MOD_DECAY_SLIDER, DEFAULT_PRESET.modEnv.decay, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, MOD_SUSTAIN_SLIDER, DEFAULT_PRESET.modEnv.sustain, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->Add(new wxSlider(panel, MOD_RELEASE_SLIDER, DEFAULT_PRESET.modEnv.release, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
+    sizer->AddSpacer(20);
+    sizer->Add(new wxSlider(panel, MOD_ENV_FLT_GAIN, DEFAULT_PRESET.modEnvFltGain, 0, 127, wxDefaultPosition, wxDefaultSize, wxSL_VERTICAL | wxSL_INVERSE));
 
     Bind(wxEVT_MENU, &SynthFrame::OnAbout, this, wxID_ABOUT);
     Bind(wxEVT_MENU, &SynthFrame::OnExit, this, wxID_EXIT);
@@ -64,6 +69,11 @@ void SynthFrame::OnFltQScroll(wxScrollEvent& event) {
     app.synth.control(0, CC_FLT_Q, event.GetPosition());
 } 
 
+void SynthFrame::OnKeyTrackScroll(wxScrollEvent& event) {
+    SynthApp& app = wxGetApp();
+    app.synth.control(0, CC_KEY_TRK, event.GetPosition());
+}
+
 void SynthFrame::OnAmpAttackScroll(wxScrollEvent& event) {
     SynthApp& app = wxGetApp();
     app.synth.control(0, CC_AMP_ATK, event.GetPosition());
@@ -104,19 +114,28 @@ void SynthFrame::OnFltReleaseScroll(wxScrollEvent& event) {
     app.synth.control(0, CC_FLT_REL, event.GetPosition());
 } 
 
+void SynthFrame::OnModEnvFltGainScroll(wxScrollEvent& event) {
+    SynthApp& app = wxGetApp();
+    app.synth.control(0, CC_MOD_FLT, event.GetPosition());
+} 
+
 wxBEGIN_EVENT_TABLE(SynthFrame, wxFrame)
 
 EVT_COMMAND_SCROLL(SynthFrame::FLT_FREQ_SLIDER, SynthFrame::OnFltFreqScroll)
 EVT_COMMAND_SCROLL(SynthFrame::FLT_Q_SLIDER, SynthFrame::OnFltQScroll)
 
+EVT_COMMAND_SCROLL(SynthFrame::KEY_TRACK_SLIDER, SynthFrame::OnKeyTrackScroll)
+
 EVT_COMMAND_SCROLL(SynthFrame::AMP_ATTACK_SLIDER, SynthFrame::OnAmpAttackScroll)
 EVT_COMMAND_SCROLL(SynthFrame::AMP_DECAY_SLIDER, SynthFrame::OnAmpDecayScroll)
 EVT_COMMAND_SCROLL(SynthFrame::AMP_SUSTAIN_SLIDER, SynthFrame::OnAmpSustainScroll)
 EVT_COMMAND_SCROLL(SynthFrame::AMP_RELEASE_SLIDER, SynthFrame::OnAmpReleaseScroll)
 
-EVT_COMMAND_SCROLL(SynthFrame::FLT_ATTACK_SLIDER, SynthFrame::OnFltAttackScroll)
-EVT_COMMAND_SCROLL(SynthFrame::FLT_DECAY_SLIDER, SynthFrame::OnFltDecayScroll)
-EVT_COMMAND_SCROLL(SynthFrame::FLT_SUSTAIN_SLIDER, SynthFrame::OnFltSustainScroll)
-EVT_COMMAND_SCROLL(SynthFrame::FLT_RELEASE_SLIDER, SynthFrame::OnFltReleaseScroll)
+EVT_COMMAND_SCROLL(SynthFrame::MOD_ATTACK_SLIDER, SynthFrame::OnFltAttackScroll)
+EVT_COMMAND_SCROLL(SynthFrame::MOD_DECAY_SLIDER, SynthFrame::OnFltDecayScroll)
+EVT_COMMAND_SCROLL(SynthFrame::MOD_SUSTAIN_SLIDER, SynthFrame::OnFltSustainScroll)
+EVT_COMMAND_SCROLL(SynthFrame::MOD_RELEASE_SLIDER, SynthFrame::OnFltReleaseScroll)
+
+EVT_COMMAND_SCROLL(SynthFrame::MOD_ENV_FLT_GAIN, SynthFrame::OnModEnvFltGainScroll)
 
 wxEND_EVENT_TABLE()