From 069225be1515db97ad446c9fb7fa7b79a1720ded Mon Sep 17 00:00:00 2001
From: Elias Aebi <eyelash@users.noreply.github.com>
Date: Thu, 12 Sep 2024 15:08:29 +0200
Subject: [PATCH] MIDI

---
 gral.h           | 14 ++++++++++++
 gral_linux.c     | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
 gral_macos.m     | 14 ++++++++++++
 gral_windows.cpp | 14 ++++++++++++
 4 files changed, 99 insertions(+)

diff --git a/gral.h b/gral.h
index 3739290..b5c098d 100644
--- a/gral.h
+++ b/gral.h
@@ -98,6 +98,11 @@ struct gral_window_interface {
 struct gral_timer;
 struct gral_file;
 struct gral_directory_watcher;
+struct gral_midi;
+struct gral_midi_interface {
+	void (*note_on)(unsigned char note, unsigned char velocity, void *user_data);
+	void (*note_off)(unsigned char note, void *user_data);
+};
 
 
 /*================
@@ -207,6 +212,15 @@ double gral_time_get_monotonic(void);
 
 void gral_audio_play(int (*callback)(float *buffer, int frames, void *user_data), void *user_data);
 
+
+/*=========
+    MIDI
+ =========*/
+
+struct gral_midi *gral_midi_create(struct gral_application *application, char const *name, struct gral_midi_interface const *interface, void *user_data);
+void gral_midi_delete(struct gral_midi *midi);
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/gral_linux.c b/gral_linux.c
index 1668b0b..689e23a 100644
--- a/gral_linux.c
+++ b/gral_linux.c
@@ -860,3 +860,60 @@ void gral_audio_play(int (*callback)(float *buffer, int frames, void *user_data)
 	snd_pcm_drain(pcm);
 	snd_pcm_close(pcm);
 }
+
+
+/*=========
+    MIDI
+ =========*/
+
+struct gral_midi {
+	struct gral_midi_interface interface;
+	void *user_data;
+	snd_seq_t *seq;
+	int port;
+	guint source_id;
+};
+
+static void connect_midi() {
+
+}
+
+static gboolean midi_callback(gint fd, GIOCondition condition, gpointer user_data) {
+	struct gral_midi *midi = user_data;
+	snd_seq_event_t *event;
+	while (snd_seq_event_input(midi->seq, &event) > 0) {
+		switch (event->type) {
+		case SND_SEQ_EVENT_NOTEON:
+			midi->interface.note_on(event->data.note.note, event->data.note.velocity, midi->user_data);
+			break;
+		case SND_SEQ_EVENT_NOTEOFF:
+			midi->interface.note_off(event->data.note.note, midi->user_data);
+			break;
+		case SND_SEQ_EVENT_CONTROLLER:
+			break;
+		default:
+			break;
+		}
+	}
+	return G_SOURCE_CONTINUE;
+}
+
+struct gral_midi *gral_midi_create(struct gral_application *application, char const *name, struct gral_midi_interface const *interface, void *user_data) {
+	struct gral_midi *midi = malloc(sizeof(struct gral_midi));
+	midi->interface = *interface;
+	midi->user_data = user_data;
+	snd_seq_open(&midi->seq, "default", SND_SEQ_OPEN_INPUT, SND_SEQ_NONBLOCK);
+	snd_seq_set_client_name(midi->seq, name);
+	int client_id = snd_seq_client_id(midi->seq);
+	midi->port = snd_seq_create_simple_port(midi->seq, name, SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE, SND_SEQ_PORT_TYPE_MIDI_GENERIC);
+	struct pollfd pfd;
+	snd_seq_poll_descriptors(midi->seq, &pfd, 1, POLLIN);
+	midi->source_id = g_unix_fd_add(pfd.fd, pfd.events, &midi_callback, midi);
+	return midi;
+}
+
+void gral_midi_delete(struct gral_midi *midi) {
+	g_source_remove(midi->source_id);
+	snd_seq_close(midi->seq);
+	free(midi);
+}
diff --git a/gral_macos.m b/gral_macos.m
index ce6a33f..c28ec7c 100644
--- a/gral_macos.m
+++ b/gral_macos.m
@@ -921,3 +921,17 @@ void gral_audio_play(int (*callback)(float *buffer, int frames, void *user_data)
 	CFRunLoopRun();
 	AudioQueueDispose(queue, NO);
 }
+
+
+/*=========
+    MIDI
+ =========*/
+
+struct gral_midi *gral_midi_create(struct gral_application *application, char const *name, struct gral_midi_interface const *interface, void *user_data) {
+	// TODO
+	return NULL;
+}
+
+void gral_midi_delete(struct gral_midi *midi) {
+	// TODO
+}
diff --git a/gral_windows.cpp b/gral_windows.cpp
index 6c2125b..3ffeca3 100644
--- a/gral_windows.cpp
+++ b/gral_windows.cpp
@@ -1390,3 +1390,17 @@ void gral_audio_play(int (*callback)(float *buffer, int frames, void *user_data)
 	render_client->Release();
 	CoTaskMemFree(format);
 }
+
+
+/*=========
+    MIDI
+ =========*/
+
+gral_midi *gral_midi_create(gral_application *application, char const *name, gral_midi_interface const *interface, void *user_data) {
+	// TODO
+	return NULL;
+}
+
+void gral_midi_delete(gral_midi *midi) {
+	// TODO
+}