Initial commit of project.

2026-03-13 15:09:17 -04:00
commit 48ee8c2c75
7 changed files with 485 additions and 0 deletions
--- a/source/midi.c
+++ b/source/midi.c
@@ -0,0 +1,111 @@
+#include "midi.h"
+#include <stdio.h>
+#include <poll.h>
+#include <stdatomic.h>
+#include <alloca.h>
+
+extern atomic_int gRunning;
+
+int midiInit(MidiState *m, Synth *synth)
+{
+    if (snd_seq_open(&m->seq, "default", SND_SEQ_OPEN_INPUT | SND_SEQ_NONBLOCK, 0) < 0) {
+        fprintf(stderr, "Failed to open ALSA sequencer\n");
+        return 0;
+    }
+    snd_seq_nonblock(m->seq, 1);
+    snd_seq_set_client_name(m->seq, "soundThing");
+    m->client = snd_seq_client_id(m->seq);
+    m->port   = snd_seq_create_simple_port(m->seq, "MIDI In",
+                                           SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE,
+                                           SND_SEQ_PORT_TYPE_APPLICATION);
+    m->synth  = synth;
+    return 1;
+}
+
+void midiListInputs(MidiState *m)
+{
+    snd_seq_client_info_t *cinfo;
+    snd_seq_port_info_t   *pinfo;
+    snd_seq_client_info_alloca(&cinfo);
+    snd_seq_port_info_alloca(&pinfo);
+
+    printf("\nAvailable MIDI inputs:\n");
+    snd_seq_client_info_set_client(cinfo, -1);
+    while (snd_seq_query_next_client(m->seq, cinfo) >= 0) {
+        int client = snd_seq_client_info_get_client(cinfo);
+        if (client == m->client) continue;
+
+        snd_seq_port_info_set_client(pinfo, client);
+        snd_seq_port_info_set_port(pinfo, -1);
+        while (snd_seq_query_next_port(m->seq, pinfo) >= 0) {
+            unsigned int caps = snd_seq_port_info_get_capability(pinfo);
+            if (caps & SND_SEQ_PORT_CAP_READ && caps & SND_SEQ_PORT_CAP_SUBS_READ) {
+                printf("  [%d:%d] %s — %s\n",
+                       client,
+                       snd_seq_port_info_get_port(pinfo),
+                       snd_seq_client_info_get_name(cinfo),
+                       snd_seq_port_info_get_name(pinfo));
+            }
+        }
+    }
+}
+
+void midiConnect(MidiState *m, int srcClient, int srcPort)
+{
+    snd_seq_port_subscribe_t *sub;
+    snd_seq_addr_t sender, dest;
+
+    sender.client = srcClient;
+    sender.port   = srcPort;
+    dest.client   = m->client;
+    dest.port     = m->port;
+
+    snd_seq_port_subscribe_alloca(&sub);
+    snd_seq_port_subscribe_set_sender(sub, &sender);
+    snd_seq_port_subscribe_set_dest(sub, &dest);
+    snd_seq_subscribe_port(m->seq, sub);
+
+    printf("Connected [%d:%d] to Cricket\n", srcClient, srcPort);
+}
+
+void midiClose(MidiState *m)
+{
+    snd_seq_close(m->seq);
+}
+
+void *midiThread(void *arg)
+{
+    MidiState      *m = (MidiState *)arg;
+    struct pollfd   pfd;
+    snd_seq_poll_descriptors(m->seq, &pfd, 1, POLLIN);
+
+    while (gRunning) {
+        int ready = poll(&pfd, 1, 50);
+        if (ready <= 0) continue;
+
+        snd_seq_event_t *ev = NULL;
+        while (snd_seq_event_input(m->seq, &ev) >= 0 && ev) {
+            switch (ev->type) {
+                case SND_SEQ_EVENT_NOTEON:
+                    if (ev->data.note.velocity == 0)
+                        synthNoteOff(m->synth, ev->data.note.note);
+                else
+                    synthNoteOn(m->synth, ev->data.note.note);
+                break;
+                case SND_SEQ_EVENT_NOTEOFF:
+                    synthNoteOff(m->synth, ev->data.note.note);
+                    break;
+                case SND_SEQ_EVENT_CONTROLLER:
+                    if (ev->data.control.param == 70)
+                        m->synth->waveform = ev->data.control.value % WAVE_COUNT;
+                break;
+                case SND_SEQ_EVENT_PITCHBEND:
+                    m->synth->pitchBend = ev->data.control.value / 8191.0f;
+                break;
+            }
+            snd_seq_free_event(ev);
+            ev = NULL;
+        }
+    }
+    return NULL;
+}