Refactor writing MIDI events to buffers

include/MidiEventToByteSeq.h

@@ -0,0 +1,45 @@
+/*
+ * MidiEventToByteSeq.h - writeToByteSeq declaration
+ *
+ * Copyright (c) 2020-2020 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * 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 2 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 (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef MIDIEVENTTOBYTESEQ_H
+#define MIDIEVENTTOBYTESEQ_H
+
+#include <cstddef>
+#include <cstdint>
+
+/**
+	Write MIDI event into byte sequence.
+
+	Conforming to http://lv2plug.in/ns/ext/midi#MidiEvent
+
+	@param data Pointer to the target buffer for the byte sequence. Must
+		point to existing memory with at least 3 bytes size.
+	@param bufsize Available size of the target buffer.
+	@return Used size of the target buffer, or 0 if the MidiEvent could not
+		be converted.
+*/
+std::size_t writeToByteSeq( const class MidiEvent& ev,
+							uint8_t* data, std::size_t bufsize );
+
+#endif // MIDIEVENTTOBYTESEQ_H

plugins/carlabase/carla.cpp

@@ -29,6 +29,7 @@
 #include "gui_templates.h"
 #include "InstrumentPlayHandle.h"
 #include "InstrumentTrack.h"
+#include "MidiEventToByteSeq.h"
 #include "Mixer.h"
 
 #include <QApplication>
@@ -372,69 +373,9 @@ bool CarlaInstrument::handleMidiEvent(const MidiEvent& event, const MidiTime&, f
 
     nEvent.port    = 0;
     nEvent.time    = offset;
-    nEvent.data[0] = event.type() | (event.channel() & 0x0F);
-
-    switch (event.type())
-    {
-    case MidiNoteOn:
-        if (event.velocity() > 0)
-        {
-            if (event.key() < 0 || event.key() > MidiMaxKey)
-                break;
-
-            nEvent.data[1] = event.key();
-            nEvent.data[2] = event.velocity();
-            nEvent.size    = 3;
-            break;
-        }
-        else
-        {
-            nEvent.data[0] = MidiNoteOff | (event.channel() & 0x0F);
-            // nobreak
-        }
-
-    case MidiNoteOff:
-        if (event.key() < 0 || event.key() > MidiMaxKey)
-            break;
-
-        nEvent.data[1] = event.key();
-        nEvent.data[2] = event.velocity();
-        nEvent.size    = 3;
-        break;
-
-    case MidiKeyPressure:
-        nEvent.data[1] = event.key();
-        nEvent.data[2] = event.velocity();
-        nEvent.size    = 3;
-        break;
-
-    case MidiControlChange:
-        nEvent.data[1] = event.controllerNumber();
-        nEvent.data[2] = event.controllerValue();
-        nEvent.size    = 3;
-        break;
-
-    case MidiProgramChange:
-        nEvent.data[1] = event.program();
-        nEvent.size    = 2;
-        break;
-
-    case MidiChannelPressure:
-        nEvent.data[1] = event.channelPressure();
-        nEvent.size    = 2;
-        break;
-
-    case MidiPitchBend:
-        nEvent.data[1] = event.pitchBend() & 0x7f;
-        nEvent.data[2] = event.pitchBend() >> 7;
-        nEvent.size    = 3;
-        break;
-
-    default:
-        // unhandled
-        --fMidiEventCount;
-        break;
-    }
+    std::size_t written = writeToByteSeq(event, nEvent.data, sizeof(NativeMidiEvent::data));
+    if(written) { nEvent.size = written; }
+    else { --fMidiEventCount; }
 
     return true;
 }

src/core/CMakeLists.txt

@@ -106,6 +106,7 @@ set(LMMS_SRCS
 	core/midi/MidiAlsaSeq.cpp
 	core/midi/MidiClient.cpp
 	core/midi/MidiController.cpp
+	core/midi/MidiEventToByteSeq.cpp
 	core/midi/MidiJack.cpp
 	core/midi/MidiOss.cpp
 	core/midi/MidiSndio.cpp

src/core/lv2/Lv2Proc.cpp

@@ -40,6 +40,7 @@
 #include "Lv2Manager.h"
 #include "Lv2Ports.h"
 #include "Lv2Evbuf.h"
+#include "MidiEventToByteSeq.h"
 #include "Mixer.h"
 
 
@@ -164,83 +165,6 @@ void Lv2Proc::dumpPorts()
 
 
 
-// this is almost completely copied from plugins/carlabase/carla.cpp
-static std::size_t midiInputEventToData(const MidiEvent& event, uint8_t* data)
-{
-	std::size_t size = 0;
-	data[0] = event.type() | (event.channel() & 0x0F);
-
-	switch (event.type())
-	{
-	case MidiNoteOn:
-		if (event.velocity() > 0)
-		{
-			if (event.key() < 0 || event.key() > MidiMaxKey)
-				break;
-
-			data[1] = event.key();
-			data[2] = event.velocity();
-			size    = 3;
-			break;
-		}
-		else
-		{
-			// Lv2 MIDI specs:
-			// "Note On messages with velocity 0 are not allowed.
-			// These messages are equivalent to Note Off in standard
-			// MIDI streams, but here only proper Note Off messages
-			// are allowed."
-			data[0] = MidiNoteOff | (event.channel() & 0x0F);
-			// nobreak
-		}
-
-	case MidiNoteOff:
-		if (event.key() < 0 || event.key() > MidiMaxKey)
-			break;
-		data[1] = event.key();
-		data[2] = event.velocity(); // release time
-		size    = 3;
-		break;
-
-	case MidiKeyPressure:
-		data[1] = event.key();
-		data[2] = event.velocity();
-		size    = 3;
-		break;
-
-	case MidiControlChange:
-		data[1] = event.controllerNumber();
-		data[2] = event.controllerValue();
-		size    = 3;
-		break;
-
-	case MidiProgramChange:
-		data[1] = event.program();
-		size    = 2;
-		break;
-
-	case MidiChannelPressure:
-		data[1] = event.channelPressure();
-		size    = 2;
-		break;
-
-	case MidiPitchBend:
-		data[1] = event.pitchBend() & 0x7f;
-		data[2] = event.pitchBend() >> 7;
-		size    = 3;
-		break;
-
-	default:
-		// unhandled
-		break;
-	}
-
-	return size;
-}
-
-
-
-
 void Lv2Proc::copyModelsFromCore()
 {
 	struct FloatFromModelVisitor : public ConstModelVisitor
@@ -302,13 +226,13 @@ void Lv2Proc::copyModelsFromCore()
 			// MIDI events waiting to go to the plugin?
 			while(m_midiInputReader.read_space() > 0)
 			{
-				MidiInputEvent ev = m_midiInputReader.read(1)[0];
+				const MidiInputEvent ev = m_midiInputReader.read(1)[0];
 				uint32_t atomStamp =
 					ev.time.frames(Engine::framesPerTick()) + ev.offset;
 				uint32_t type = Engine::getLv2Manager()->
 					uridCache()[Lv2UridCache::Id::midi_MidiEvent];
 				uint8_t buf[4];
-				std::size_t bufsize = midiInputEventToData(ev.ev, buf);
+				std::size_t bufsize = writeToByteSeq(ev.ev, buf, sizeof(buf));
 				if(bufsize)
 				{
 					lv2_evbuf_write(&iter, atomStamp, type, bufsize, buf);

src/core/midi/MidiEventToByteSeq.cpp

@@ -0,0 +1,107 @@
+/*
+ * MidiEventToByteSeq.cpp - writeToByteSeq implementation
+ *
+ * Copyright (c) 2020-2020 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * 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 2 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 (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "MidiEventToByteSeq.h"
+
+#include <QtGlobal>
+
+#include "MidiEvent.h"
+
+
+std::size_t writeToByteSeq(
+	const MidiEvent& ev, uint8_t *data, std::size_t bufsize)
+{
+	Q_ASSERT(bufsize >= 3);
+
+	std::size_t size = 0;
+	data[0] = ev.type() | (ev.channel() & 0x0F);
+
+	switch (ev.type())
+	{
+		case MidiNoteOn:
+			if (ev.velocity() > 0)
+			{
+				if (ev.key() < 0 || ev.key() > MidiMaxKey)
+					break;
+
+				data[1] = ev.key();
+				data[2] = ev.velocity();
+				size    = 3;
+				break;
+			}
+			else
+			{
+				// Lv2 MIDI specs:
+				// "Note On messages with velocity 0 are not allowed.
+				// These messages are equivalent to Note Off in standard
+				// MIDI streams, but here only proper Note Off messages
+				// are allowed."
+				data[0] = MidiNoteOff | (ev.channel() & 0x0F);
+				// nobreak
+			}
+
+		case MidiNoteOff:
+			if (ev.key() < 0 || ev.key() > MidiMaxKey)
+				break;
+			data[1] = ev.key();
+			data[2] = ev.velocity(); // release time
+			size    = 3;
+			break;
+
+		case MidiKeyPressure:
+			data[1] = ev.key();
+			data[2] = ev.velocity();
+			size    = 3;
+			break;
+
+		case MidiControlChange:
+			data[1] = ev.controllerNumber();
+			data[2] = ev.controllerValue();
+			size    = 3;
+			break;
+
+		case MidiProgramChange:
+			data[1] = ev.program();
+			size    = 2;
+			break;
+
+		case MidiChannelPressure:
+			data[1] = ev.channelPressure();
+			size    = 2;
+			break;
+
+		case MidiPitchBend:
+			data[1] = ev.pitchBend() & 0x7f;
+			data[2] = ev.pitchBend() >> 7;
+			size    = 3;
+			break;
+
+		default:
+			// unhandled
+			break;
+	}
+
+	return size;
+}
+