Lots + MIDI implementation

crates/forth/src/vm.rs

@@ -790,6 +790,75 @@ impl Forth {
                         val *= ratio;
                     }
                 }
+
+                // MIDI operations
+                Op::MidiEmit => {
+                    let (_, params) = cmd.snapshot().unwrap_or((None, &[]));
+                    let get_int = |name: &str| -> Option<i64> {
+                        params
+                            .iter()
+                            .rev()
+                            .find(|(k, _)| k == name)
+                            .and_then(|(_, v)| v.as_int().ok())
+                    };
+                    let get_float = |name: &str| -> Option<f64> {
+                        params
+                            .iter()
+                            .rev()
+                            .find(|(k, _)| k == name)
+                            .and_then(|(_, v)| v.as_float().ok())
+                    };
+                    let chan = get_int("chan")
+                        .map(|c| (c.clamp(1, 16) - 1) as u8)
+                        .unwrap_or(0);
+
+                    if let (Some(cc), Some(val)) = (get_int("ccnum"), get_int("ccout")) {
+                        let cc = cc.clamp(0, 127) as u8;
+                        let val = val.clamp(0, 127) as u8;
+                        outputs.push(format!("/midi/cc/{cc}/{val}/chan/{chan}"));
+                    } else if let Some(bend) = get_float("bend") {
+                        let bend_clamped = bend.clamp(-1.0, 1.0);
+                        let bend_14bit = ((bend_clamped + 1.0) * 8191.5) as u16;
+                        outputs.push(format!("/midi/bend/{bend_14bit}/chan/{chan}"));
+                    } else if let Some(pressure) = get_int("pressure") {
+                        let pressure = pressure.clamp(0, 127) as u8;
+                        outputs.push(format!("/midi/pressure/{pressure}/chan/{chan}"));
+                    } else if let Some(program) = get_int("program") {
+                        let program = program.clamp(0, 127) as u8;
+                        outputs.push(format!("/midi/program/{program}/chan/{chan}"));
+                    } else {
+                        let note = get_int("note").unwrap_or(60).clamp(0, 127) as u8;
+                        let velocity = get_int("velocity").unwrap_or(100).clamp(0, 127) as u8;
+                        let dur = get_float("dur").unwrap_or(1.0);
+                        let dur_secs = dur * ctx.step_duration();
+                        outputs.push(format!("/midi/note/{note}/vel/{velocity}/chan/{chan}/dur/{dur_secs}"));
+                    }
+                }
+                Op::MidiClock => {
+                    outputs.push("/midi/clock".to_string());
+                }
+                Op::MidiStart => {
+                    outputs.push("/midi/start".to_string());
+                }
+                Op::MidiStop => {
+                    outputs.push("/midi/stop".to_string());
+                }
+                Op::MidiContinue => {
+                    outputs.push("/midi/continue".to_string());
+                }
+                Op::GetMidiCC => {
+                    let chan = stack.pop().ok_or("stack underflow")?.as_int()?;
+                    let cc = stack.pop().ok_or("stack underflow")?.as_int()?;
+                    let cc_clamped = (cc.clamp(0, 127)) as usize;
+                    let chan_clamped = (chan.clamp(1, 16) - 1) as usize;
+                    let val = ctx
+                        .cc_memory
+                        .as_ref()
+                        .and_then(|mem| mem.lock().ok())
+                        .map(|mem| mem[chan_clamped][cc_clamped])
+                        .unwrap_or(0);
+                    stack.push(Value::Int(val as i64, None));
+                }
             }
             pc += 1;
         }