Move MIDI parsing up from ALSA driver to platform independent driver.

Aims for more consistent MIDI support across Windows, MacOS, Linux and
to provide a base for adding MIDI drivers for other platforms.
Reworks the MIDIDriverALSAMidi MIDI parsing implementation as a platform
independent version in MIDIDriver::Parser.
Uses MIDIDriver::Parser to provide running status support in MacOS
MIDIDriverCoreMidi.
Collects connected input names at open, ensuring devices indices reported
in events match names in array returned from get_connected_inputs.

Fixes #77035.
Fixes #79811.

With code review changes by: A Thousand Ships (she/her)
<96648715+AThousandShips@users.noreply.github.com>

2 files changed, 28 insertions, 35 deletions

diff --git a/drivers/winmidi/midi_driver_winmidi.cpp b/drivers/winmidi/midi_driver_winmidi.cpp
index 07f0226c5d..0f37f63ccd 100644
--- a/drivers/winmidi/midi_driver_winmidi.cpp
+++ b/drivers/winmidi/midi_driver_winmidi.cpp
@@ -36,26 +36,42 @@
 
 void MIDIDriverWinMidi::read(HMIDIIN hMidiIn, UINT wMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2) {
 	if (wMsg == MIM_DATA) {
-		receive_input_packet((int)dwInstance, (uint64_t)dwParam2, (uint8_t *)&dwParam1, 3);
+		// For MIM_DATA: dwParam1 = wMidiMessage, dwParam2 = dwTimestamp.
+		// Windows implementation has already unpacked running status and dropped any SysEx,
+		// so we can just forward straight to the event.
+		const uint8_t *midi_msg = (uint8_t *)&dwParam1;
+		send_event((int)dwInstance, midi_msg[0], &midi_msg[1], 2);
 	}
 }
 
 Error MIDIDriverWinMidi::open() {
+	int device_index = 0;
 	for (UINT i = 0; i < midiInGetNumDevs(); i++) {
 		HMIDIIN midi_in;
+		MIDIINCAPS caps;
 
-		MMRESULT res = midiInOpen(&midi_in, i, (DWORD_PTR)read, (DWORD_PTR)i, CALLBACK_FUNCTION);
-		if (res == MMSYSERR_NOERROR) {
+		MMRESULT open_res = midiInOpen(&midi_in, i, (DWORD_PTR)read,
+				(DWORD_PTR)device_index, CALLBACK_FUNCTION);
+		MMRESULT caps_res = midiInGetDevCaps(i, &caps, sizeof(MIDIINCAPS));
+
+		if (open_res == MMSYSERR_NOERROR) {
 			midiInStart(midi_in);
-			connected_sources.insert(i, midi_in);
+			connected_sources.push_back(midi_in);
+			if (caps_res == MMSYSERR_NOERROR) {
+				connected_input_names.push_back(caps.szPname);
+			} else {
+				// Should push something even if we don't get a name,
+				// so that the IDs line up correctly on the script side.
+				connected_input_names.push_back("ERROR");
+			}
+			// Only increment device index for successfully connected devices.
+			device_index++;
 		} else {
 			char err[256];
-			midiInGetErrorText(res, err, 256);
+			midiInGetErrorText(open_res, err, 256);
 			ERR_PRINT("midiInOpen error: " + String(err));
 
-			MIDIINCAPS caps;
-			res = midiInGetDevCaps(i, &caps, sizeof(MIDIINCAPS));
-			if (res == MMSYSERR_NOERROR) {
+			if (caps_res == MMSYSERR_NOERROR) {
 				ERR_PRINT("Can't open MIDI device \"" + String(caps.szPname) + "\", is it being used by another application?");
 			}
 		}
@@ -64,25 +80,6 @@ Error MIDIDriverWinMidi::open() {
 	return OK;
 }
 
-PackedStringArray MIDIDriverWinMidi::get_connected_inputs() {
-	PackedStringArray list;
-
-	for (int i = 0; i < connected_sources.size(); i++) {
-		HMIDIIN midi_in = connected_sources[i];
-		UINT id = 0;
-		MMRESULT res = midiInGetID(midi_in, &id);
-		if (res == MMSYSERR_NOERROR) {
-			MIDIINCAPS caps;
-			res = midiInGetDevCaps(i, &caps, sizeof(MIDIINCAPS));
-			if (res == MMSYSERR_NOERROR) {
-				list.push_back(caps.szPname);
-			}
-		}
-	}
-
-	return list;
-}
-
 void MIDIDriverWinMidi::close() {
 	for (int i = 0; i < connected_sources.size(); i++) {
 		HMIDIIN midi_in = connected_sources[i];
@@ -90,9 +87,7 @@ void MIDIDriverWinMidi::close() {
 		midiInClose(midi_in);
 	}
 	connected_sources.clear();
-}
-
-MIDIDriverWinMidi::MIDIDriverWinMidi() {
+	connected_input_names.clear();
 }
 
 MIDIDriverWinMidi::~MIDIDriverWinMidi() {
diff --git a/drivers/winmidi/midi_driver_winmidi.h b/drivers/winmidi/midi_driver_winmidi.h
index f3e016f378..7a75252233 100644
--- a/drivers/winmidi/midi_driver_winmidi.h
+++ b/drivers/winmidi/midi_driver_winmidi.h
@@ -48,12 +48,10 @@ class MIDIDriverWinMidi : public MIDIDriver {
 	static void CALLBACK read(HMIDIIN hMidiIn, UINT wMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2);
 
 public:
-	virtual Error open();
-	virtual void close();
+	virtual Error open() override;
+	virtual void close() override;
 
-	virtual PackedStringArray get_connected_inputs();
-
-	MIDIDriverWinMidi();
+	MIDIDriverWinMidi() = default;
 	virtual ~MIDIDriverWinMidi();
 };