Allow enabling and disabling operators, closes #111 (#118)

* Allow enabling and disabling operators, closes #111

Thanks @rsta2

src/dexedadapter.h

@@ -25,6 +25,8 @@
 #include <circle/spinlock.h>
 #include <stdint.h>
 
+#define DEXED_OP_ENABLE (DEXED_OP_OSC_DETUNE + 1)
+
 // Some Dexed methods require to be guarded from being interrupted
 // by other Dexed calls. This is done herein.
 

src/minidexed.cpp

@@ -68,6 +68,7 @@ CMiniDexed::CMiniDexed (CConfig *pConfig, CInterruptSystem *pInterrupt,
 		m_nNoteShift[i] = 0;
 
 		m_nReverbSend[i] = 0;
+		m_uchOPMask[i] = 0b111111;	// All operators on
 
 		m_pTG[i] = new CDexedAdapter (CConfig::MaxNotes, pConfig->GetSampleRate ());
 		assert (m_pTG[i]);
@@ -676,6 +677,22 @@ void CMiniDexed::SetVoiceParameter (uint8_t uchOffset, uint8_t uchValue, unsigne
 
 	if (nOP < 6)
 	{
+		if (uchOffset == DEXED_OP_ENABLE)
+		{
+			if (uchValue)
+			{
+				m_uchOPMask[nTG] |= 1 << nOP;
+			}
+			else
+			{
+				m_uchOPMask[nTG] &= ~(1 << nOP);
+			}
+
+			m_pTG[nTG]->setOPAll (m_uchOPMask[nTG]);
+
+			return;
+		}
+
 		nOP = 5 - nOP;		// OPs are in reverse order
 	}
 
@@ -693,6 +710,11 @@ uint8_t CMiniDexed::GetVoiceParameter (uint8_t uchOffset, unsigned nOP, unsigned
 
 	if (nOP < 6)
 	{
+		if (uchOffset == DEXED_OP_ENABLE)
+		{
+			return !!(m_uchOPMask[nTG] & (1 << nOP));
+		}
+
 		nOP = 5 - nOP;		// OPs are in reverse order
 	}
 

src/minidexed.h

@@ -126,6 +126,7 @@ public:
 
 private:
 	int16_t ApplyNoteLimits (int16_t pitch, unsigned nTG);	// returns < 0 to ignore note
+	uint8_t m_uchOPMask[CConfig::ToneGenerators];
 	
 	void ProcessSound (void);
 

src/uimenu.cpp

@@ -152,6 +152,7 @@ const CUIMenu::TMenuItem CUIMenu::s_OperatorMenu[] =
 	{"Rate Scaling",EditOPParameter,	0,	DEXED_OP_OSC_RATE_SCALE},
 	{"A Mod Sens.",	EditOPParameter,	0,	DEXED_OP_AMP_MOD_SENS},
 	{"K Vel. Sens.",EditOPParameter,	0,	DEXED_OP_KEY_VEL_SENS},
+	{"Enable", EditOPParameter, 0, DEXED_OP_ENABLE},
 	{0}
 };
 
@@ -235,7 +236,8 @@ const CUIMenu::TParameter CUIMenu::s_OPParameter[] =
 	{0,	1,	1,	ToOscillatorMode},	// DEXED_OP_OSC_MODE
 	{0,	31,	1},				// DEXED_OP_FREQ_COARSE
 	{0,	99,	1},				// DEXED_OP_FREQ_FINE
-	{0,	14,	1,	ToOscillatorDetune}	// DEXED_OP_OSC_DETUNE
+	{0,	14,	1,	ToOscillatorDetune},	// DEXED_OP_OSC_DETUNE
+	{0, 1, 1, ToOnOff}		// DEXED_OP_ENABLE
 };
 
 const char CUIMenu::s_NoteName[100][4] =