Make MIDI CC mapping configurable

The MIDI CC mapping can be configured with the file midi-cc.txt on the
SD card now. The file format should be self explanatory. A default
config file is the config/ directory.

Issue #12

README.md

@@ -67,7 +67,7 @@ Furthermore you need the Raspberry Pi firmware. You can get it as follows:
 
 You have to copy the three files *bootcode.bin*, *start.elf* and *fixup.dat* from the *circle/boot/* subdirectory to the FAT partition on the SD card. The Raspberry Pi 4 requires different firmware files. Please read the file *circle/boot/README* for details!
 
-Finally you have to copy the configuration files *cmdline.txt*, *patchN.txt* (example patches) and *velocity-???.txt* (keyboard velocity curve) from the *config/* subdirectory to the SD card. The appropriate velocity curve file has to be renamed to *velocity.txt* to be used. You can optionally create a subdirectory */patches* and copy the example patches there, if you do not want to have them in the root directory of your SD card.
+Finally you have to copy the configuration files *cmdline.txt*, *patchN.txt* (example patches), *velocity-???.txt* (keyboard velocity curve) and *midi-cc.txt* (MIDI CC mapping) from the *config/* subdirectory to the SD card. The appropriate velocity curve file has to be renamed to *velocity.txt* to be used. You can optionally create a subdirectory */patches* and copy the example patches there, if you do not want to have them in the root directory of your SD card.
 
 Put the SD card into the card reader of your Raspberry Pi.
 
@@ -129,7 +129,7 @@ One patch of MiniSynth Pi has the following parameters:
 | Section    | Module   | Parameter | Unit | Range     | Default | Description          | MIDI CC |
 | ---------- | -------- | --------- | ---- | --------- | ------- | -------------------- | ------- |
 | OSCILLATOR | VCO      | Wave      |      |           | Square  | Waveform (*)         |         |
-| OSCILLATOR | VCO (2)  | Detune    | %    | 0-200     | 100     | Semitone -/+         |         |
+| OSCILLATOR | VCO (2)  | Detune    | %    | 0-200     | 100     | Semitone -/+         | 94 (**) |
 | OSCILLATOR | LFO      | Wave      |      |           | Sine    | Waveform (*)         |         |
 | OSCILLATOR | LFO      | Rate      | Hz   | 1-35      | 20      | Modulation frequency |         |
 | OSCILLATOR | LFO      | Volume    | %    | 0-100     | 0       | Modulation volume    |         |
@@ -151,10 +151,12 @@ One patch of MiniSynth Pi has the following parameters:
 | AMPLIFIER  | ENVELOPE | Sustain   | %    | 0-100     | 100     | Sustain level        |         |
 | AMPLIFIER  | ENVELOPE | Release   | ms   | 0-5000    | 100     | Release delay        |         |
 | EFFECTS    | REVERB   | Decay     | %    | 0-50      | 20      | Rate of decay        |         |
-| EFFECTS    | REVERB   | Volume    | %    | 0-30      | 0       | Wet/dry ratio        |         |
+| EFFECTS    | REVERB   | Volume    | %    | 0-30      | 0       | Wet/dry ratio        | 91      |
 
 (*) Waveform can be: Sine, Square, Sawtooth, Triangle, Pulse 12.5%, Pulse 25% or Noise (Noise not for LFO)
 
+(\*\*) The MIDI CC mapping can be modified in the file *midi-cc.txt*. This is the default mapping.
+
 MiniSynth Pi provides two VCOs, one runs at the pitch frequency, the other at pitch frequency detuned by a configurable value (max. one semitone - or +, default 100% = Detune off).
 
 MiniSynth Pi allows to use a specific keyboard velocity curve, which fits best to your keyboard and your playing style. It has to be provided in the file *velocity.txt* on the SD card. The default velocity curve is linear. Have a look into the example files in the *config/* subdirectory. If you want to use one of these files, it has to be renamed to *velocity.txt* on the SD card. It should be easy to modify one example file to adjust the velocity curve to your own needs.

config/midi-cc.txt

@@ -0,0 +1,27 @@
+#
+# MIDI CC Mapping
+#
+LFOVCOWaveform=
+LFOVCOFrequency=
+VCOWaveform=
+VCOModulationVolume=
+VCODetune=94
+LFOVCFWaveform=
+LFOVCFFrequency=
+VCFCutoffFrequency=74
+VCFResonance=71
+EGVCFAttack=
+EGVCFDecay=
+EGVCFSustain=
+EGVCFRelease=
+VCFModulationVolume=
+LFOVCAWaveform=
+LFOVCAFrequency=
+EGVCAAttack=
+EGVCADecay=
+EGVCASustain=
+EGVCARelease=
+VCAModulationVolume=
+ReverbDecay=
+ReverbVolume=91
+SynthVolume=7

src/Makefile

@@ -9,7 +9,7 @@ CIRCLEHOME ?= ../circle
 OBJS	= main.o kernel.o minisynth.o mididevice.o \
 	  midikeyboard.o pckeyboard.o serialmididevice.o voicemanager.o \
 	  voice.o oscillator.o mixer.o filter.o amplifier.o envelopegenerator.o \
-	  reverbmodule.o synthconfig.o patch.o parameter.o velocitycurve.o \
+	  reverbmodule.o synthconfig.o patch.o parameter.o velocitycurve.o midiccmap.o \
 	  mainwindow.o guiparameter.o guistringproperty.o
 
 LIBS	= $(CIRCLEHOME)/addon/lvgl/liblvgl.a \

src/midiccmap.cpp

@@ -0,0 +1,67 @@
+//
+// midiccmap.h
+//
+// MiniSynth Pi - A virtual analogue synthesizer for Raspberry Pi
+// Copyright (C) 2021  R. Stange <[email protected]>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+#include "midiccmap.h"
+#include "config.h"
+#include <assert.h>
+
+CMIDICCMap::CMIDICCMap (FATFS *pFileSystem)
+:	m_Properties (DRIVE "/midi-cc.txt", pFileSystem)
+{
+	for (unsigned i = MIDICC_MIN; i <= MIDICC_MAX; i++)
+	{
+		m_Map[i] = SynthParameterUnknown;
+	}
+}
+
+CMIDICCMap::~CMIDICCMap (void)
+{
+}
+
+boolean CMIDICCMap::Load (void)
+{
+	boolean bResult = m_Properties.Load ();
+	if (!bResult)
+	{
+		m_Properties.RemoveAll ();
+	}
+
+	for (unsigned i = 0; i < SynthParameterUnknown; i++)
+	{
+		unsigned nMIDICC =
+			m_Properties.GetNumber (CPatch::GetParameterName ((TSynthParameter) i), 0);
+
+		if (MIDICC_MIN <= nMIDICC && nMIDICC <= MIDICC_MAX)
+		{
+			m_Map[nMIDICC] = (TSynthParameter) i;
+		}
+	}
+
+	return bResult;
+}
+
+TSynthParameter CMIDICCMap::Map (u8 ucMIDICC) const
+{
+	if (MIDICC_MIN <= ucMIDICC && ucMIDICC <= MIDICC_MAX)
+	{
+		return m_Map[ucMIDICC];
+	}
+
+	return SynthParameterUnknown;
+}

src/midiccmap.h

@@ -0,0 +1,49 @@
+//
+// midiccmap.h
+//
+// Maps MIDI CC numbers to TSynthParameter
+//
+// MiniSynth Pi - A virtual analogue synthesizer for Raspberry Pi
+// Copyright (C) 2021  R. Stange <[email protected]>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+#ifndef _midiccmap_h
+#define _midiccmap_h
+
+#include <fatfs/ff.h>
+#include <circle/types.h>
+#include <Properties/propertiesfatfsfile.h>
+#include "patch.h"
+
+#define MIDICC_MIN	1
+#define MIDICC_MAX	127
+
+class CMIDICCMap
+{
+public:
+	CMIDICCMap (FATFS *pFileSystem);
+	~CMIDICCMap (void);
+
+	boolean Load (void);
+
+	TSynthParameter Map (u8 ucMIDICC) const;
+
+private:
+	CPropertiesFatFsFile m_Properties;
+
+	TSynthParameter m_Map[MIDICC_MAX+1];
+};
+
+#endif

src/minisynth.cpp

@@ -2,7 +2,7 @@
 // minisynth.cpp
 //
 // MiniSynth Pi - A virtual analogue synthesizer for Raspberry Pi
-// Copyright (C) 2017-2020  R. Stange <[email protected]>
+// Copyright (C) 2017-2021  R. Stange <[email protected]>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -133,19 +133,13 @@ boolean CMiniSynthesizer::ConfigUpdated (void)
 
 void CMiniSynthesizer::ControlChange (u8 ucFunction, u8 ucValue)
 {
-	TSynthParameter Parameter;
-
-	switch (ucFunction)
+	assert (m_pConfig != 0);
+	TSynthParameter Parameter = m_pConfig->MapMIDICC (ucFunction);
+	if (Parameter >= SynthParameterUnknown)
 	{
-	case 7:		Parameter = SynthVolume;		break;
-	case 71:	Parameter = VCFResonance;		break;
-	case 74:	Parameter = VCFCutoffFrequency;		break;
-
-	default:
 		return;
 	}
 
-	assert (m_pConfig != 0);
 	CPatch *pPatch = m_pConfig->GetActivePatch ();
 	assert (pPatch != 0);
 

src/patch.cpp

@@ -2,7 +2,7 @@
 // patch.cpp
 //
 // MiniSynth Pi - A virtual analogue synthesizer for Raspberry Pi
-// Copyright (C) 2017-2020  R. Stange <[email protected]>
+// Copyright (C) 2017-2021  R. Stange <[email protected]>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -21,7 +21,7 @@
 #include "oscillator.h"
 #include <assert.h>
 
-static struct
+static const struct
 {
 	const char	*pName;
 	TParameterType	 Type;
@@ -74,7 +74,7 @@ ParameterList[] =		// must match TSynthParameter
 	{"SynthVolume", ParameterPercent, 0, 100, 10, 50, "Volume"}
 };
 
-static struct
+static const struct
 {
 	const char	*pName;
 	unsigned	 nMaxLength;
@@ -188,9 +188,12 @@ void CPatch::SetParameter (TSynthParameter Parameter, unsigned nValue)
 void CPatch::SetMIDIParameter (TSynthParameter Parameter, u8 ucValue)
 {
 	assert (Parameter < SynthParameterUnknown);
-	assert (ParameterList[Parameter].Type == ParameterPercent);
 
-	unsigned nValue = (ucValue*100 + 63) / 127;
+	unsigned nValue = ucValue;
+	nValue *= ParameterList[Parameter].nMaximum - ParameterList[Parameter].nMinimum;
+	nValue = (nValue + 63) / 127;
+	nValue += ParameterList[Parameter].nMinimum;
+
 	nValue =   (nValue + ParameterList[Parameter].nStep/2)
 		 / ParameterList[Parameter].nStep
 		 * ParameterList[Parameter].nStep;
@@ -262,3 +265,9 @@ const char *CPatch::GetPropertyHelp (TPatchProperty Property)
 	assert (Property < PatchPropertyUnknown);
 	return PropertyList[Property].pHelp;
 }
+
+const char *CPatch::GetParameterName (TSynthParameter Parameter)
+{
+	assert (Parameter < SynthParameterUnknown);
+	return ParameterList[Parameter].pName;
+}

src/patch.h

@@ -4,7 +4,7 @@
 // Container for patch settings, loadable from properties file
 //
 // MiniSynth Pi - A virtual analogue synthesizer for Raspberry Pi
-// Copyright (C) 2017-2020  R. Stange <[email protected]>
+// Copyright (C) 2017-2021  R. Stange <[email protected]>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -108,6 +108,8 @@ class CPatch
 	static boolean GetPropertyUppercase (TPatchProperty Property);
 	static const char *GetPropertyHelp (TPatchProperty Property);
 
+	static const char *GetParameterName (TSynthParameter Parameter);
+
 private:
 	CPropertiesFatFsFile m_Properties;
 

src/synthconfig.cpp

@@ -2,7 +2,7 @@
 // synthconfig.cpp
 //
 // MiniSynth Pi - A virtual analogue synthesizer for Raspberry Pi
-// Copyright (C) 2017-2020  R. Stange <[email protected]>
+// Copyright (C) 2017-2021  R. Stange <[email protected]>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,7 +25,8 @@
 CSynthConfig::CSynthConfig (FATFS *pFileSystem)
 :	m_pFileSystem (pFileSystem),
 	m_nActivePatch (0),
-	m_VelocityCurve (pFileSystem)
+	m_VelocityCurve (pFileSystem),
+	m_MIDICCMap (pFileSystem)
 {
 	for (unsigned i = 0; i < PATCHES; i++)
 	{
@@ -62,7 +63,11 @@ boolean CSynthConfig::Load (void)
 		assert (m_pPatch[i] != 0);
 	}
 
-	return m_VelocityCurve.Load ();
+	boolean bOK = m_VelocityCurve.Load ();
+
+	bOK = m_MIDICCMap.Load () && bOK;
+
+	return bOK;
 }
 
 unsigned CSynthConfig::GetActivePatchNumber (void) const
@@ -94,3 +99,8 @@ u8 CSynthConfig::MapVelocity (u8 ucVelocity) const
 {
 	return m_VelocityCurve.MapVelocity (ucVelocity);
 }
+
+TSynthParameter CSynthConfig::MapMIDICC (u8 ucMIDICC) const
+{
+	return m_MIDICCMap.Map (ucMIDICC);
+}

src/synthconfig.h

@@ -4,7 +4,7 @@
 // Container for global configuration and all patches
 //
 // MiniSynth Pi - A virtual analogue synthesizer for Raspberry Pi
-// Copyright (C) 2017-2020  R. Stange <[email protected]>
+// Copyright (C) 2017-2021  R. Stange <[email protected]>
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -25,6 +25,7 @@
 #include <fatfs/ff.h>
 #include "patch.h"
 #include "velocitycurve.h"
+#include "midiccmap.h"
 #include "config.h"
 
 class CSynthConfig
@@ -47,6 +48,7 @@ class CSynthConfig
 	CPatch *GetPatch (unsigned nPatch);
 
 	u8 MapVelocity (u8 ucVelocity) const;
+	TSynthParameter MapMIDICC (u8 ucMIDICC) const;
 
 private:
 	FATFS *m_pFileSystem;
@@ -55,6 +57,7 @@ class CSynthConfig
 	unsigned m_nActivePatch;
 
 	CVelocityCurve m_VelocityCurve;
+	CMIDICCMap m_MIDICCMap;
 };
 
 #endif