Initial implementation of MIDI learn (per plugin, not global)

Closes #26

Signed-off-by: falkTX <falktx@falktx.com>

source/backend/CarlaBackend.h

@@ -779,10 +779,15 @@ typedef enum {
      */
     CONTROL_INDEX_MIDI_PITCHBEND = 131,
 
+    /*!
+     * Special value to indicate MIDI learn.
+     */
+    CONTROL_INDEX_MIDI_LEARN = 132,
+
     /*!
      * Highest index allowed for mappings.
      */
-    CONTROL_INDEX_MAX_ALLOWED = CONTROL_INDEX_MIDI_PITCHBEND
+    CONTROL_INDEX_MAX_ALLOWED = CONTROL_INDEX_MIDI_LEARN
 
 } SpecialMappedControlIndex;
 

source/backend/CarlaEngine.hpp

@@ -178,6 +178,7 @@ struct CARLA_API EngineControlEvent {
     EngineControlEventType type; //!< Control-Event type.
     uint16_t param;              //!< Parameter Id, midi bank or midi program.
     float    value;              //!< Parameter value, normalized to 0.0f<->1.0f.
+    bool     handled;            //!< Indicates that event was handled/received at least once.
 
     /*!
      * Convert this control event into MIDI data.
@@ -575,12 +576,12 @@ public:
      * Get the event at @a index.
      * @note You must only call this for input ports.
      */
-    virtual const EngineEvent& getEvent(uint32_t index) const noexcept;
+    virtual EngineEvent& getEvent(uint32_t index) const noexcept;
 
     /*!
      * Get the event at @a index, faster unchecked version.
      */
-    virtual const EngineEvent& getEventUnchecked(uint32_t index) const noexcept;
+    virtual EngineEvent& getEventUnchecked(uint32_t index) const noexcept;
 
     /*!
      * Write a control event into the buffer.

source/backend/CarlaPlugin.hpp

@@ -51,6 +51,7 @@ class CarlaEngineEventPort;
 class CarlaEngineCVSourcePorts;
 class CarlaEngineBridge;
 struct CarlaStateSave;
+struct EngineEvent;
 
 // -----------------------------------------------------------------------
 
@@ -891,6 +892,12 @@ public:
      */
     CarlaEngineEventPort* getDefaultEventOutPort() const noexcept;
 
+    /*!
+     * Check if the plugin is interested on MIDI learn, and if so, map this event to the parameter that wants it.
+     * Event MUST be of control type and not have been handled before.
+     */
+    void checkForMidiLearn(EngineEvent& event) noexcept;
+
     /*!
      * Get the plugin's type native handle.
      * This will be LADSPA_Handle, LV2_Handle, etc.

source/backend/engine/CarlaEngineData.cpp

@@ -108,18 +108,21 @@ void EngineEvent::fillFromMidiData(const uint8_t size, const uint8_t* const data
             ctrl.type  = kEngineControlEventTypeMidiBank;
             ctrl.param = midiBank;
             ctrl.value = 0.0f;
+            ctrl.handled = true;
         }
         else if (midiControl == MIDI_CONTROL_ALL_SOUND_OFF)
         {
             ctrl.type  = kEngineControlEventTypeAllSoundOff;
             ctrl.param = 0;
             ctrl.value = 0.0f;
+            ctrl.handled = true;
         }
         else if (midiControl == MIDI_CONTROL_ALL_NOTES_OFF)
         {
             ctrl.type  = kEngineControlEventTypeAllNotesOff;
             ctrl.param = 0;
             ctrl.value = 0.0f;
+            ctrl.handled = true;
         }
         else
         {
@@ -130,6 +133,7 @@ void EngineEvent::fillFromMidiData(const uint8_t size, const uint8_t* const data
             ctrl.type  = kEngineControlEventTypeParameter;
             ctrl.param = midiControl;
             ctrl.value = float(midiValue)/127.0f;
+            ctrl.handled = false;
         }
     }
     else if (midiStatus == MIDI_STATUS_PROGRAM_CHANGE)
@@ -143,6 +147,7 @@ void EngineEvent::fillFromMidiData(const uint8_t size, const uint8_t* const data
         ctrl.type  = kEngineControlEventTypeMidiProgram;
         ctrl.param = midiProgram;
         ctrl.value = 0.0f;
+        ctrl.handled = true;
     }
     else
     {

source/backend/engine/CarlaEngineJack.cpp

@@ -124,7 +124,9 @@ static /* */ PortNameToId   kPortNameToIdFallbackNC  = { 0, 0, { '\0' }, { '\0'
 static const PortNameToId   kPortNameToIdFallback    = { 0, 0, { '\0' }, { '\0' } };
 static const ConnectionToId kConnectionToIdFallback  = { 0, 0, 0, 0, 0 };
 #endif
-static const EngineEvent    kFallbackJackEngineEvent = { kEngineEventTypeNull, 0, 0, {{ kEngineControlEventTypeNull, 0, 0.0f }} };
+static EngineEvent kFallbackJackEngineEvent = {
+    kEngineEventTypeNull, 0, 0, {{ kEngineControlEventTypeNull, 0, 0.0f, true }}
+};
 
 // -----------------------------------------------------------------------
 // Carla Engine Port removal helper
@@ -460,7 +462,7 @@ public:
         } CARLA_SAFE_EXCEPTION_RETURN("jack_midi_get_event_count", 0);
     }
 
-    const EngineEvent& getEvent(const uint32_t index) const noexcept override
+    EngineEvent& getEvent(const uint32_t index) const noexcept override
     {
         if (fJackPort == nullptr)
             return CarlaEngineEventPort::getEvent(index);
@@ -471,7 +473,7 @@ public:
         return getEventUnchecked(index);
     }
 
-    const EngineEvent& getEventUnchecked(uint32_t index) const noexcept override
+    EngineEvent& getEventUnchecked(uint32_t index) const noexcept override
     {
 #ifndef BUILD_BRIDGE_ALTERNATIVE_ARCH
         if (index < fCvSourceEventCount)
@@ -529,7 +531,7 @@ public:
 
         uint8_t data[3] = { 0, 0, 0 };
 
-        EngineControlEvent ctrlEvent = { type, param, value };
+        EngineControlEvent ctrlEvent = { type, param, value, false };
         const uint8_t size = ctrlEvent.convertToMidiData(channel, data);
 
         if (size == 0)

source/backend/engine/CarlaEnginePorts.cpp

@@ -31,8 +31,9 @@ CARLA_BACKEND_START_NAMESPACE
 // -----------------------------------------------------------------------
 // Fallback data
 
-static const EngineEvent kFallbackEngineEvent = { kEngineEventTypeNull, 0, 0, {{ kEngineControlEventTypeNull, 0, 0.0f }} };
-//static CarlaEngineEventCV kFallbackEngineEventCV = { nullptr, (uint32_t)-1, 0.0f };
+static EngineEvent kFallbackEngineEvent = {
+    kEngineEventTypeNull, 0, 0, {{ kEngineControlEventTypeNull, 0, 0.0f, true }}
+};
 
 // -----------------------------------------------------------------------
 // Carla Engine port (Abstract)
@@ -169,7 +170,7 @@ uint32_t CarlaEngineEventPort::getEventCount() const noexcept
     return i;
 }
 
-const EngineEvent& CarlaEngineEventPort::getEvent(const uint32_t index) const noexcept
+EngineEvent& CarlaEngineEventPort::getEvent(const uint32_t index) const noexcept
 {
     CARLA_SAFE_ASSERT_RETURN(kIsInput, kFallbackEngineEvent);
     CARLA_SAFE_ASSERT_RETURN(fBuffer != nullptr, kFallbackEngineEvent);
@@ -179,7 +180,7 @@ const EngineEvent& CarlaEngineEventPort::getEvent(const uint32_t index) const no
     return fBuffer[index];
 }
 
-const EngineEvent& CarlaEngineEventPort::getEventUnchecked(const uint32_t index) const noexcept
+EngineEvent& CarlaEngineEventPort::getEventUnchecked(const uint32_t index) const noexcept
 {
     return fBuffer[index];
 }

source/backend/plugin/CarlaPlugin.cpp

@@ -21,6 +21,7 @@
 #include "CarlaBackendUtils.hpp"
 #include "CarlaBase64Utils.hpp"
 #include "CarlaMathUtils.hpp"
+#include "CarlaMIDI.h"
 #include "CarlaPluginUI.hpp"
 #include "CarlaScopeUtils.hpp"
 #include "CarlaStringList.hpp"
@@ -1789,6 +1790,11 @@ void CarlaPlugin::setParameterMappedControlIndex(const uint32_t parameterId, con
     paramData.mappedControlIndex = index;
 
 #ifndef BUILD_BRIDGE_ALTERNATIVE_ARCH
+    if (index == CONTROL_INDEX_MIDI_LEARN)
+        pData->midiLearnParameterIndex = static_cast<int32_t>(parameterId);
+    else
+        pData->midiLearnParameterIndex = -1;
+
     pData->engine->callback(sendCallback, sendOsc,
                             ENGINE_CALLBACK_PARAMETER_MAPPED_CONTROL_INDEX_CHANGED,
                             pData->id,
@@ -2258,6 +2264,33 @@ void CarlaPlugin::idle()
                                         0, 0.0f, nullptr);
             }
         } break;
+
+        case kPluginPostRtEventMidiLearn: {
+            CARLA_SAFE_ASSERT_BREAK(event.value1 >= 0 && event.value1 < MAX_MIDI_CHANNELS);
+            CARLA_SAFE_ASSERT_BREAK(event.value2 >= 0 && event.value2 < MAX_MIDI_NOTE);
+
+            if (event.sendCallback)
+            {
+                const int32_t parameterId = event.value1;
+                const int32_t midiCC      = event.value2;
+                const int32_t midiChannel = event.value2;
+
+                pData->engine->callback(true, true,
+                                        ENGINE_CALLBACK_PARAMETER_MAPPED_CONTROL_INDEX_CHANGED,
+                                        pData->id,
+                                        parameterId,
+                                        midiCC,
+                                        0, 0.0f, nullptr);
+
+                pData->engine->callback(true, true,
+                                        ENGINE_CALLBACK_PARAMETER_MIDI_CHANNEL_CHANGED,
+                                        pData->id,
+                                        parameterId,
+                                        midiChannel,
+                                        0, 0.0f, nullptr);
+
+            }
+        } break;
         }
     }
 }
@@ -2405,6 +2438,7 @@ void CarlaPlugin::uiIdle()
             {
             case kPluginPostRtEventNull:
             case kPluginPostRtEventDebug:
+            case kPluginPostRtEventMidiLearn:
                 break;
 
             case kPluginPostRtEventParameterChange:
@@ -2538,6 +2572,31 @@ CarlaEngineEventPort* CarlaPlugin::getDefaultEventOutPort() const noexcept
     return pData->event.portOut;
 }
 
+void CarlaPlugin::checkForMidiLearn(EngineEvent& event) noexcept
+{
+    if (pData->midiLearnParameterIndex < 0)
+        return;
+    if (event.ctrl.param == MIDI_CONTROL_BANK_SELECT || event.ctrl.param == MIDI_CONTROL_BANK_SELECT__LSB)
+        return;
+    if (event.ctrl.param >= MAX_MIDI_CONTROL)
+        return;
+
+    const uint32_t parameterId = static_cast<uint32_t>(pData->midiLearnParameterIndex);
+    CARLA_SAFE_ASSERT_UINT2_RETURN(parameterId < pData->param.count, parameterId, pData->param.count,);
+
+    ParameterData& paramData(pData->param.data[parameterId]);
+    CARLA_SAFE_ASSERT_INT_RETURN(paramData.mappedControlIndex == CONTROL_INDEX_MIDI_LEARN,
+                                 paramData.mappedControlIndex,);
+
+    event.ctrl.handled = true;
+    paramData.mappedControlIndex = static_cast<int16_t>(event.ctrl.param);
+    paramData.midiChannel = event.channel;
+
+    pData->postponeRtEvent(kPluginPostRtEventMidiLearn, true,
+                           pData->midiLearnParameterIndex, event.ctrl.param, event.channel, 0.0f);
+    pData->midiLearnParameterIndex = -1;
+}
+
 void* CarlaPlugin::getNativeHandle() const noexcept
 {
     return nullptr;

source/backend/plugin/CarlaPluginBridge.cpp

@@ -1365,6 +1365,17 @@ public:
 
                     case kEngineControlEventTypeParameter:
 #ifndef BUILD_BRIDGE_ALTERNATIVE_ARCH
+                        // non-midi
+                        if (event.channel == kEngineEventNonMidiChannel)
+                        {
+                            const uint32_t k = ctrlEvent.param;
+                            CARLA_SAFE_ASSERT_CONTINUE(k < pData->param.count);
+
+                            // value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
+                            // setParameterValueRT(k, value, true);
+                            continue;
+                        }
+
                         // Control backend stuff
                         if (event.channel == pData->ctrlChannel)
                         {

source/backend/plugin/CarlaPluginInternal.cpp

@@ -673,6 +673,7 @@ CarlaPlugin::ProtectedData::ProtectedData(CarlaEngine* const eng, const uint idx
       ctrlChannel(0),
       extraHints(0x0),
 #ifndef BUILD_BRIDGE_ALTERNATIVE_ARCH
+      midiLearnParameterIndex(-1),
       transientTryCounter(0),
       transientFirstTry(true),
 #endif

source/backend/plugin/CarlaPluginInternal.hpp

@@ -86,7 +86,8 @@ enum PluginPostRtEventType {
     kPluginPostRtEventProgramChange,     // index
     kPluginPostRtEventMidiProgramChange, // index
     kPluginPostRtEventNoteOn,            // channel, note, velo
-    kPluginPostRtEventNoteOff            // channel, note
+    kPluginPostRtEventNoteOff,           // channel, note
+    kPluginPostRtEventMidiLearn          // param, cc, channel
 };
 
 /*!
@@ -244,8 +245,9 @@ struct CarlaPlugin::ProtectedData {
     int8_t ctrlChannel;
     uint   extraHints;
 #ifndef BUILD_BRIDGE_ALTERNATIVE_ARCH
-    uint   transientTryCounter;
-    bool   transientFirstTry;
+    int32_t midiLearnParameterIndex;
+    uint    transientTryCounter;
+    bool    transientFirstTry;
 #endif
 
     // data 1

source/backend/plugin/CarlaPluginJuce.cpp

@@ -864,7 +864,7 @@ public:
 
             for (uint32_t i=0, numEvents=pData->event.portIn->getEventCount(); i < numEvents; ++i)
             {
-                const EngineEvent& event(pData->event.portIn->getEvent(i));
+                EngineEvent& event(pData->event.portIn->getEvent(i));
 
                 if (event.time >= frames)
                     continue;
@@ -875,7 +875,7 @@ public:
                     break;
 
                 case kEngineEventTypeControl: {
-                    const EngineControlEvent& ctrlEvent(event.ctrl);
+                    EngineControlEvent& ctrlEvent(event.ctrl);
 
                     switch (ctrlEvent.type)
                     {
@@ -892,6 +892,7 @@ public:
                             const uint32_t k = ctrlEvent.param;
                             CARLA_SAFE_ASSERT_CONTINUE(k < pData->param.count);
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                             continue;
@@ -902,17 +903,17 @@ public:
                         {
                             if (MIDI_IS_CONTROL_BREATH_CONTROLLER(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_DRYWET) != 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value;
                                 setDryWetRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) != 0)
+                            else if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) != 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value*127.0f/100.0f;
                                 setVolumeRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) != 0)
+                            else if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) != 0)
                             {
                                 float left, right;
                                 value = ctrlEvent.value/0.5f - 1.0f;
@@ -933,6 +934,7 @@ public:
                                     right = 1.0f;
                                 }
 
+                                ctrlEvent.handled = true;
                                 setBalanceLeftRT(left, true);
                                 setBalanceRightRT(right, true);
                             }
@@ -951,6 +953,7 @@ public:
                             if ((pData->param.data[k].hints & PARAMETER_IS_AUTOMABLE) == 0)
                                 continue;
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                         }
@@ -965,6 +968,9 @@ public:
                             fMidiBuffer.addEvent(midiData, 3, static_cast<int>(event.time));
                         }
 
+                        if (! ctrlEvent.handled)
+                            checkForMidiLearn(event);
+
                         break;
                     } // case kEngineControlEventTypeParameter
 

source/backend/plugin/CarlaPluginLADSPADSSI.cpp

@@ -1602,7 +1602,7 @@ public:
 
             for (uint32_t i=0, numEvents=pData->event.portIn->getEventCount(); i < numEvents; ++i)
             {
-                const EngineEvent& event(pData->event.portIn->getEvent(i));
+                EngineEvent& event(pData->event.portIn->getEvent(i));
 
                 uint32_t eventTime = event.time;
                 CARLA_SAFE_ASSERT_UINT2_CONTINUE(eventTime < frames, eventTime, frames);
@@ -1637,7 +1637,7 @@ public:
                     break;
 
                 case kEngineEventTypeControl: {
-                    const EngineControlEvent& ctrlEvent(event.ctrl);
+                    EngineControlEvent& ctrlEvent(event.ctrl);
 
                     switch (ctrlEvent.type)
                     {
@@ -1654,6 +1654,7 @@ public:
                             const uint32_t k = ctrlEvent.param;
                             CARLA_SAFE_ASSERT_CONTINUE(k < pData->param.count);
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                             continue;
@@ -1664,17 +1665,17 @@ public:
                         {
                             if (MIDI_IS_CONTROL_BREATH_CONTROLLER(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_DRYWET) != 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value;
                                 setDryWetRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) != 0)
+                            else if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) != 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value*127.0f/100.0f;
                                 setVolumeRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) != 0)
+                            else if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) != 0)
                             {
                                 float left, right;
                                 value = ctrlEvent.value/0.5f - 1.0f;
@@ -1695,6 +1696,7 @@ public:
                                     right = 1.0f;
                                 }
 
+                                ctrlEvent.handled = true;
                                 setBalanceLeftRT(left, true);
                                 setBalanceRightRT(right, true);
                             }
@@ -1712,6 +1714,7 @@ public:
                             if ((pData->param.data[k].hints & PARAMETER_IS_AUTOMABLE) == 0)
                                 continue;
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                         }
@@ -1731,6 +1734,9 @@ public:
                             seqEvent.data.control.value   = int8_t(ctrlEvent.value*127.0f);
                         }
 
+                        if (! ctrlEvent.handled)
+                            checkForMidiLearn(event);
+
                         break;
                     } // case kEngineControlEventTypeParameter
 

source/backend/plugin/CarlaPluginLV2.cpp

@@ -3749,7 +3749,7 @@ public:
 
             for (uint32_t i=0; i < numEvents; ++i)
             {
-                const EngineEvent& event(fEventsIn.ctrl->port->getEvent(i));
+                EngineEvent& event(fEventsIn.ctrl->port->getEvent(i));
 
                 uint32_t eventTime = event.time;
                 CARLA_SAFE_ASSERT_UINT2_CONTINUE(eventTime < frames, eventTime, frames);
@@ -3821,7 +3821,7 @@ public:
                     break;
 
                 case kEngineEventTypeControl: {
-                    const EngineControlEvent& ctrlEvent(event.ctrl);
+                    EngineControlEvent& ctrlEvent(event.ctrl);
 
                     switch (ctrlEvent.type)
                     {
@@ -3838,6 +3838,7 @@ public:
                             const uint32_t k = ctrlEvent.param;
                             CARLA_SAFE_ASSERT_CONTINUE(k < pData->param.count);
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                             continue;
@@ -3848,17 +3849,17 @@ public:
                         {
                             if (MIDI_IS_CONTROL_BREATH_CONTROLLER(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_DRYWET) != 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value;
                                 setDryWetRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) != 0)
+                            else if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) != 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value*127.0f/100.0f;
                                 setVolumeRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) != 0)
+                            else if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) != 0)
                             {
                                 float left, right;
                                 value = ctrlEvent.value/0.5f - 1.0f;
@@ -3879,6 +3880,7 @@ public:
                                     right = 1.0f;
                                 }
 
+                                ctrlEvent.handled = true;
                                 setBalanceLeftRT(left, true);
                                 setBalanceRightRT(right, true);
                             }
@@ -3897,6 +3899,7 @@ public:
                             if ((pData->param.data[k].hints & PARAMETER_IS_AUTOMABLE) == 0)
                                 continue;
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                         }
@@ -3920,6 +3923,9 @@ public:
                                 lv2midi_put_event(&evInMidiStates[fEventsIn.ctrlIndex], mtime, 3, midiData);
                         }
 
+                        if (! ctrlEvent.handled)
+                            checkForMidiLearn(event);
+
                         break;
                     } // case kEngineControlEventTypeParameter
 

source/backend/plugin/CarlaPluginNative.cpp

@@ -97,7 +97,9 @@ CARLA_BACKEND_START_NAMESPACE
 // Fallback data
 
 static const CustomData  kCustomDataFallback = { nullptr, nullptr, nullptr };
-static const EngineEvent kNullEngineEvent    = { kEngineEventTypeNull, 0, 0, {} };
+static EngineEvent kNullEngineEvent = {
+    kEngineEventTypeNull, 0, 0, {{ kEngineControlEventTypeNull, 0, 0.0f, true }}
+};
 
 // -----------------------------------------------------------------------
 
@@ -1684,7 +1686,7 @@ public:
         }
     }
 
-    const EngineEvent& findNextEvent()
+    EngineEvent& findNextEvent()
     {
         if (fMidiIn.count == 1)
         {
@@ -1909,7 +1911,7 @@ public:
 
             for (;;)
             {
-                const EngineEvent& event(findNextEvent());
+                EngineEvent& event(findNextEvent());
 
                 if (event.type == kEngineEventTypeNull)
                     break;
@@ -1959,7 +1961,7 @@ public:
                     break;
 
                 case kEngineEventTypeControl: {
-                    const EngineControlEvent& ctrlEvent = event.ctrl;
+                    EngineControlEvent& ctrlEvent(event.ctrl);
 
                     switch (ctrlEvent.type)
                     {
@@ -1976,6 +1978,7 @@ public:
                             const uint32_t k = ctrlEvent.param;
                             CARLA_SAFE_ASSERT_CONTINUE(k < pData->param.count);
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                             continue;
@@ -1986,17 +1989,17 @@ public:
                         {
                             if (MIDI_IS_CONTROL_BREATH_CONTROLLER(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_DRYWET) > 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value;
                                 setDryWetRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) > 0)
+                            else if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) > 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value*127.0f/100.0f;
                                 setVolumeRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) > 0)
+                            else if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) > 0)
                             {
                                 float left, right;
                                 value = ctrlEvent.value/0.5f - 1.0f;
@@ -2017,6 +2020,7 @@ public:
                                     right = 1.0f;
                                 }
 
+                                ctrlEvent.handled = true;
                                 setBalanceLeftRT(left, true);
                                 setBalanceRightRT(right, true);
                             }
@@ -2034,6 +2038,7 @@ public:
                             if ((pData->param.data[k].hints & PARAMETER_IS_AUTOMABLE) == 0)
                                 continue;
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                         }
@@ -2053,6 +2058,9 @@ public:
                             nativeEvent.size    = 3;
                         }
 
+                        if (! ctrlEvent.handled)
+                            checkForMidiLearn(event);
+
                         break;
                     } // case kEngineControlEventTypeParameter
 

source/backend/plugin/CarlaPluginVST2.cpp

@@ -1302,7 +1302,7 @@ public:
 
             for (uint32_t i=0, numEvents = pData->event.portIn->getEventCount(); i < numEvents; ++i)
             {
-                const EngineEvent& event(pData->event.portIn->getEvent(i));
+                EngineEvent& event(pData->event.portIn->getEvent(i));
 
                 uint32_t eventTime = event.time;
                 CARLA_SAFE_ASSERT_UINT2_CONTINUE(eventTime < frames, eventTime, frames);
@@ -1337,7 +1337,7 @@ public:
                     break;
 
                 case kEngineEventTypeControl: {
-                    const EngineControlEvent& ctrlEvent(event.ctrl);
+                    EngineControlEvent& ctrlEvent(event.ctrl);
 
                     switch (ctrlEvent.type)
                     {
@@ -1354,6 +1354,7 @@ public:
                             const uint32_t k = ctrlEvent.param;
                             CARLA_SAFE_ASSERT_CONTINUE(k < pData->param.count);
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                             continue;
@@ -1364,17 +1365,17 @@ public:
                         {
                             if (MIDI_IS_CONTROL_BREATH_CONTROLLER(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_DRYWET) != 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value;
                                 setDryWetRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) != 0)
+                            else if (MIDI_IS_CONTROL_CHANNEL_VOLUME(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_VOLUME) != 0)
                             {
+                                ctrlEvent.handled = true;
                                 value = ctrlEvent.value*127.0f/100.0f;
                                 setVolumeRT(value, true);
                             }
-
-                            if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) != 0)
+                            else if (MIDI_IS_CONTROL_BALANCE(ctrlEvent.param) && (pData->hints & PLUGIN_CAN_BALANCE) != 0)
                             {
                                 float left, right;
                                 value = ctrlEvent.value/0.5f - 1.0f;
@@ -1395,6 +1396,7 @@ public:
                                     right = 1.0f;
                                 }
 
+                                ctrlEvent.handled = true;
                                 setBalanceLeftRT(left, true);
                                 setBalanceRightRT(right, true);
                             }
@@ -1413,6 +1415,7 @@ public:
                             if ((pData->param.data[k].hints & PARAMETER_IS_AUTOMABLE) == 0)
                                 continue;
 
+                            ctrlEvent.handled = true;
                             value = pData->param.getFinalUnnormalizedValue(k, ctrlEvent.value);
                             setParameterValueRT(k, value, true);
                         }
@@ -1433,6 +1436,9 @@ public:
                             vstMidiEvent.midiData[2] = char(ctrlEvent.value*127.0f);
                         }
 
+                        if (! ctrlEvent.handled)
+                            checkForMidiLearn(event);
+
                         break;
                     } // case kEngineControlEventTypeParameter
 

source/frontend/carla_backend.py

@@ -562,13 +562,19 @@ PARAMETER_MAX = -9
 # @see ParameterData::mappedControlIndex
 
 # Unused control index, meaning no mapping is enabled.
-CONTROL_VALUE_NONE = -1
+CONTROL_INDEX_NONE = -1
 
 # CV control index, meaning the parameter is exposed as CV port.
-CONTROL_VALUE_CV = 130
+CONTROL_INDEX_CV = 130
 
 # Special value to indicate MIDI pitchbend.
-CONTROL_VALUE_MIDI_PITCHBEND = 131
+CONTROL_INDEX_MIDI_PITCHBEND = 131
+
+# Special value to indicate MIDI learn.
+CONTROL_INDEX_MIDI_LEARN = 132
+
+# Special value to indicate MIDI pitchbend.
+CONTROL_INDEX_MAX_ALLOWED = CONTROL_INDEX_MIDI_LEARN
 
 # ---------------------------------------------------------------------------------------------------------------------
 # Engine Callback Opcode
@@ -1227,7 +1233,7 @@ PyParameterData = {
     'index': PARAMETER_NULL,
     'rindex': -1,
     'midiChannel': 0,
-    'mappedControlIndex': CONTROL_VALUE_NONE,
+    'mappedControlIndex': CONTROL_INDEX_NONE,
     'mappedMinimum': 0.0,
     'mappedMaximum': 0.0,
 }

source/frontend/carla_widgets.py

@@ -73,9 +73,10 @@ from carla_backend import (
     PARAMETER_USES_CUSTOM_TEXT,
     PARAMETER_CAN_BE_CV_CONTROLLED,
     PARAMETER_INPUT, PARAMETER_OUTPUT,
-    CONTROL_VALUE_NONE,
-    CONTROL_VALUE_MIDI_PITCHBEND,
-    CONTROL_VALUE_CV
+    CONTROL_INDEX_NONE,
+    CONTROL_INDEX_MIDI_PITCHBEND,
+    CONTROL_INDEX_MIDI_LEARN,
+    CONTROL_INDEX_CV
 )
 
 from carla_shared import (
@@ -390,10 +391,14 @@ class PluginParameter(QWidget):
         self.ui.l_name.setFixedWidth(width)
 
     def updateStatusLabel(self):
-        if self.fMappedCtrl == CONTROL_VALUE_NONE:
+        if self.fMappedCtrl == CONTROL_INDEX_NONE:
             text = self.tr("Unmapped")
-        elif self.fMappedCtrl == CONTROL_VALUE_CV:
+        elif self.fMappedCtrl == CONTROL_INDEX_CV:
             text = self.tr("CV export")
+        elif self.fMappedCtrl == CONTROL_INDEX_MIDI_PITCHBEND:
+            text = self.tr("PBend Ch%i" % (self.fMidiChannel,))
+        elif self.fMappedCtrl == CONTROL_INDEX_MIDI_LEARN:
+            text = self.tr("MIDI Learn")
         else:
             text = self.tr("CC%i Ch%i" % (self.fMappedCtrl, self.fMidiChannel))
 
@@ -403,14 +408,18 @@ class PluginParameter(QWidget):
     def slot_optionsCustomMenu(self):
         menu = QMenu(self)
 
-        if self.fMappedCtrl == CONTROL_VALUE_NONE:
+        if self.fMappedCtrl == CONTROL_INDEX_NONE:
             title = self.tr("Unmapped")
-        elif self.fMappedCtrl == CONTROL_VALUE_CV:
+        elif self.fMappedCtrl == CONTROL_INDEX_CV:
             title = self.tr("Exposed as CV port")
+        elif self.fMappedCtrl == CONTROL_INDEX_MIDI_PITCHBEND:
+            title = self.tr("Mapped to MIDI Pitchbend, channel %i" % (self.fMidiChannel,))
+        elif self.fMappedCtrl == CONTROL_INDEX_MIDI_LEARN:
+            title = self.tr("MIDI Learn active")
         else:
             title = self.tr("Mapped to MIDI control %i, channel %i" % (self.fMappedCtrl, self.fMidiChannel))
 
-        if self.fMappedCtrl != CONTROL_VALUE_NONE:
+        if self.fMappedCtrl != CONTROL_INDEX_NONE:
             title += " (range: %g-%g)" % (self.fMappedMinimum, self.fMappedMaximum)
 
         actTitle = menu.addAction(title)
@@ -420,14 +429,14 @@ class PluginParameter(QWidget):
 
         actUnmap = menu.addAction(self.tr("Unmap"))
 
-        if self.fMappedCtrl == CONTROL_VALUE_NONE:
+        if self.fMappedCtrl == CONTROL_INDEX_NONE:
             actUnmap.setCheckable(True)
             actUnmap.setChecked(True)
 
         if self.fCanBeInCV:
             menu.addSection("CV")
             actCV = menu.addAction(self.tr("Expose as CV port"))
-            if self.fMappedCtrl == CONTROL_VALUE_CV:
+            if self.fMappedCtrl == CONTROL_INDEX_CV:
                 actCV.setCheckable(True)
                 actCV.setChecked(True)
         else:
@@ -435,9 +444,18 @@ class PluginParameter(QWidget):
 
         menu.addSection("MIDI")
 
+        actLearn = menu.addAction(self.tr("MIDI Learn"))
+
+        if self.fMappedCtrl == CONTROL_INDEX_MIDI_LEARN:
+            actLearn.setCheckable(True)
+            actLearn.setChecked(True)
+
         menuMIDI = menu.addMenu(self.tr("MIDI Control"))
 
-        if self.fMappedCtrl not in (CONTROL_VALUE_NONE, CONTROL_VALUE_CV, CONTROL_VALUE_MIDI_PITCHBEND):
+        if self.fMappedCtrl not in (CONTROL_INDEX_NONE,
+                                    CONTROL_INDEX_CV,
+                                    CONTROL_INDEX_MIDI_PITCHBEND,
+                                    CONTROL_INDEX_MIDI_LEARN):
             action = menuMIDI.menuAction()
             action.setCheckable(True)
             action.setChecked(True)
@@ -475,7 +493,7 @@ class PluginParameter(QWidget):
         # TODO
         #actPitchbend = menu.addAction(self.tr("MIDI Pitchbend"))
 
-        #if self.fMappedCtrl == CONTROL_VALUE_MIDI_PITCHBEND:
+        #if self.fMappedCtrl == CONTROL_INDEX_MIDI_PITCHBEND:
             #actPitchbend.setCheckable(True)
             #actPitchbend.setChecked(True)
 
@@ -490,8 +508,8 @@ class PluginParameter(QWidget):
                 action.setCheckable(True)
                 action.setChecked(True)
 
-        if self.fMappedCtrl != CONTROL_VALUE_NONE:
-            if self.fMappedCtrl == CONTROL_VALUE_CV:
+        if self.fMappedCtrl != CONTROL_INDEX_NONE:
+            if self.fMappedCtrl == CONTROL_INDEX_CV:
                 menu.addSection("Range (Scaled CV input)")
             else:
                 menu.addSection("Range (MIDI bounds)")
@@ -517,8 +535,8 @@ class PluginParameter(QWidget):
                                                self.tr("Custom Minimum"),
                                                "Custom minimum value to use:",
                                                self.fMappedMinimum,
-                                               self.fMinimum if self.fMappedCtrl != CONTROL_VALUE_CV else -9e6,
-                                               self.fMaximum if self.fMappedCtrl != CONTROL_VALUE_CV else 9e6,
+                                               self.fMinimum if self.fMappedCtrl != CONTROL_INDEX_CV else -9e6,
+                                               self.fMaximum if self.fMappedCtrl != CONTROL_INDEX_CV else 9e6,
                                                self.fDecimalPoints)
             if not ok:
                 return
@@ -532,8 +550,8 @@ class PluginParameter(QWidget):
                                                self.tr("Custom Maximum"),
                                                "Custom maximum value to use:",
                                                self.fMappedMaximum,
-                                               self.fMinimum if self.fMappedCtrl != CONTROL_VALUE_CV else -9e6,
-                                               self.fMaximum if self.fMappedCtrl != CONTROL_VALUE_CV else 9e6,
+                                               self.fMinimum if self.fMappedCtrl != CONTROL_INDEX_CV else -9e6,
+                                               self.fMaximum if self.fMappedCtrl != CONTROL_INDEX_CV else 9e6,
                                                self.fDecimalPoints)
             if not ok:
                 return
@@ -543,11 +561,9 @@ class PluginParameter(QWidget):
             return
 
         if actSel == actUnmap:
-            ctrl = CONTROL_VALUE_NONE
+            ctrl = CONTROL_INDEX_NONE
         elif actSel == actCV:
-            ctrl = CONTROL_VALUE_CV
-        elif actSel in actCCs:
-            ctrl = int(actSel.text().split(" ", 1)[0].replace("&",""), 10)
+            ctrl = CONTROL_INDEX_CV
         elif actSel == actCustomCC:
             value = self.fMappedCtrl if self.fMappedCtrl >= 0x01 and self.fMappedCtrl <= 0x77 else 1
             ctrl, ok = QInputDialog.getInt(self,
@@ -557,8 +573,12 @@ class PluginParameter(QWidget):
                                            0x01, 0x77, 1)
             if not ok:
                 return
-        #elif actSel in actPitchbend:
-            #ctrl = CONTROL_VALUE_MIDI_PITCHBEND
+        #elif actSel == actPitchbend:
+            #ctrl = CONTROL_INDEX_MIDI_PITCHBEND
+        elif actSel == actLearn:
+            ctrl = CONTROL_INDEX_MIDI_LEARN
+        elif actSel in actCCs:
+            ctrl = int(actSel.text().split(" ", 1)[0].replace("&",""), 10)
         else:
             return
 

source/utils/CarlaStateUtils.cpp

@@ -1,6 +1,6 @@
 /*
  * Carla State utils
- * Copyright (C) 2012-2018 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2012-2020 Filipe Coelho <falktx@falktx.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -455,7 +455,8 @@ bool CarlaStateSave::fillFromXmlElement(const XmlElement* const xmlElement)
                         {
                             const int ctrl(pText.getIntValue());
                             if (ctrl > CONTROL_INDEX_NONE && ctrl <= CONTROL_INDEX_MAX_ALLOWED)
-                                stateParameter->mappedControlIndex = static_cast<int16_t>(ctrl);
+                                if (ctrl != CONTROL_INDEX_MIDI_LEARN)
+                                    stateParameter->mappedControlIndex = static_cast<int16_t>(ctrl);
                         }
                         else if (pTag == "MappedMinimum")
                         {