New MIDI parameter syntax for --ctrlmidich arg

As part of issue jamulussoftware#95, this implements a new way of specifying various
controllers.  The previous possibilities are retained.  This leaves

--ctrlmidich <n> receives on channel n (if 0, on all channels), offset
   to first fader is 70 (Behringer X-Touch)

--ctrlmidich <n>;<off> for specifying a different offset

--ctrlmidich <n>;f<off>*<channels>;p<off>*<channels> specified offsets
for fader controllers and pan controllers, respectively.

There are also s<off> and m<off> specs for Solo and Mute buttons,
respectively.

This only concerns the command line parsing: the actual implementation
is only there for the volume faders.

src/soundbase.cpp

@@ -24,6 +24,15 @@
 
 #include "soundbase.h"
 
+char const sMidiCtlChar[] =
+{
+    [EMidiCtlType::Fader] = 'f',
+    [EMidiCtlType::Pan] = 'p',
+    [EMidiCtlType::Solo] = 's',
+    [EMidiCtlType::Mute] = 'm',
+    [EMidiCtlType::None] = '\0'
+};
+
 
 /* Implementation *************************************************************/
 CSoundBase::CSoundBase ( const QString& strNewSystemDriverTechniqueName,
@@ -248,17 +257,51 @@ void CSoundBase::ParseCommandLineArgument ( const QString& strMIDISetup )
             iCtrlMIDIChannel = slMIDIParams[0].toUInt();
         }
 
+        bool bSimple = true;
+
         // [offset for level]
         if ( slMIDIParams.count() >= 2 )
         {
-            iMIDIOffsetFader = slMIDIParams[1].toUInt();
+            int i = slMIDIParams[1].toUInt (&bSimple);
+            if (bSimple)
+                iMIDIOffsetFader = i;
         }
 
-        for (int i = 0; i < MAX_NUM_CHANNELS; i++)
+        if (bSimple)
         {
-            if (i + iMIDIOffsetFader > 127)
-                break;
-            aMidiCtls[i + iMIDIOffsetFader] = { EMidiCtlType::Fader, i };
+            for (int i = 0; i < MAX_NUM_CHANNELS; i++)
+            {
+                if (i + iMIDIOffsetFader > 127)
+                    break;
+                aMidiCtls[i + iMIDIOffsetFader] = { EMidiCtlType::Fader, i };
+            }
+            return;
+        }
+
+        // We have named controllers
+
+        for (int i = 1; i < slMIDIParams.count(); i++)
+        {
+            QString sParm = slMIDIParams[i].toLower ().remove ( ' ' );
+            if ( sParm.isEmpty() )
+                continue;
+
+            int iCtrl = QString ( sMidiCtlChar ).indexOf ( sParm[0] );
+            if (iCtrl < 0)
+                continue;
+            EMidiCtlType eTyp = static_cast<EMidiCtlType>( iCtrl );
+
+            const QStringList slP = sParm.mid ( 1 ).split ( '*' );
+            int iFirst = slP[0].toUInt ();
+            int iNum = ( slP.count() > 1 ) ? slP[1].toUInt () : 1;
+            for (int iOff = 0; iOff < iNum; iOff++)
+            {
+                if (iOff >= MAX_NUM_CHANNELS)
+                    break;
+                if (iFirst + iOff >= 128)
+                    break;
+                aMidiCtls[iFirst + iOff] = { eTyp, iOff };
+            }
         }
     }
 }