fixes #83, load proper instrument on WASM

Author: yjpark

apps/notation_viewer/index.html

@@ -24,19 +24,31 @@
       }
     </style>
 		<script src='https://surikov.github.io/webaudiofont/npm/dist/WebAudioFontPlayer.js'></script>
-		<script src='https://surikov.github.io/webaudiofontdata/sound/0250_SoundBlasterOld_sf2.js'></script>
 		<script>
 			var AudioContextFunc = window.AudioContext || window.webkitAudioContext;
 			var audioContext = new AudioContextFunc();
+      var channels = new Map();
 			var player=new WebAudioFontPlayer();
-			player.loader.decodeAfterLoading(audioContext, '_tone_0250_SoundBlasterOld_sf2');
 
-			function play_note(semitones, seconds){
-				player.queueWaveTable(audioContext, audioContext.destination
-					, _tone_0250_SoundBlasterOld_sf2, 0, semitones, seconds);
+			function play_note(channel, semitones, seconds, volume){
+        const info = channels.get(channel);
+        if (info) {
+          player.queueWaveTable(audioContext, audioContext.destination, window[info.variable], 0, semitones, seconds, volume);
+        }
 			}
 
-      function load_instrument(program) {
+      function init_channel(channel, program) {
+				var nn = player.loader.findInstrument(program);
+        var info = player.loader.instrumentInfo(nn);
+        channels.set(channel, info);
+        console.log('init_channel(', channel, program, ') -> info:', info);
+        player.loader.startLoad(audioContext, info.url, info.variable);
+      }
+
+      function load_instruments() {
+        player.loader.waitLoad(function () {
+          console.log('load_instruments: finished', channels);
+        });
       }
 		</script>
   </head>

crates/notation_midi/src/midi_hub.rs

@@ -1,8 +1,8 @@
 use midir::{MidiOutput, MidiOutputConnection};
-use notation_model::prelude::PlaySpeed;
-use std::sync::Mutex;
+use notation_model::prelude::{PlaySpeed, Tab};
+use std::sync::{Arc, Mutex};
 
-use crate::prelude::{MidiMessage, MidiSettings, MidiSynth};
+use crate::prelude::{MidiMessage, MidiSettings, MidiState, MidiSynth};
 
 pub struct MidiHub {
     pub output_conn: Option<Mutex<MidiOutputConnection>>,
@@ -63,6 +63,16 @@ impl MidiHub {
             self.check_output_conn();
         }
     }
+    pub fn switch_tab(&mut self, settings: &MidiSettings, state: &mut MidiState, tab: Arc<Tab>) {
+        state.switch_tab(&settings, self, tab.clone());
+        self.init_channels(settings, state);
+    }
+    pub fn init_channels(&mut self, settings: &MidiSettings, state: &MidiState) {
+        self.check_output(settings);
+        if let Some(synth) = &self.output_synth {
+            synth.init_channels(settings, state);
+        }
+    }
     pub fn send(&mut self, settings: &MidiSettings, speed: &PlaySpeed, msg: &MidiMessage) {
         self.check_output(settings);
         if let Some(synth) = &self.output_synth {

crates/notation_midi/src/midi_plugin.rs

@@ -33,7 +33,7 @@ fn on_switch_tab(
     mut play_control_evts: EventWriter<PlayControlEvent>,
 ) {
     for evt in evts.iter() {
-        state.switch_tab(&settings, &mut hub, evt.tab.clone());
+        hub.switch_tab(&settings, &mut state, evt.tab.clone());
         _do_tick(
             &settings,
             &mut state,

crates/notation_midi/src/native/midi_synth.rs

@@ -1,6 +1,6 @@
 use helgoboss_midi::StructuredShortMessage;
 
-use crate::prelude::MidiMessage;
+use crate::prelude::{MidiMessage, MidiSettings, MidiState};
 use notation_model::prelude::PlaySpeed;
 
 use super::audio_stream::DoubleAudioBuffer;
@@ -42,6 +42,8 @@ impl MidiSynth {
             synth.write(data).unwrap();
         });
     }
+    pub fn init_channels(&self, _settings: &MidiSettings, _state: &MidiState) {
+    }
     pub fn send(&self, _speed: &PlaySpeed, msg: &MidiMessage) -> Result<(), String> {
         match msg.midi {
             StructuredShortMessage::NoteOff {

crates/notation_midi/src/wasm/midi_synth.rs

@@ -1,7 +1,7 @@
 use helgoboss_midi::StructuredShortMessage;
 use wasm_bindgen::prelude::*;
 
-use crate::prelude::MidiMessage;
+use crate::prelude::{MidiMessage, MidiSettings, MidiState};
 use notation_model::prelude::{Entry, PlaySpeed};
 
 pub struct MidiSynth {}
@@ -10,6 +10,14 @@ impl MidiSynth {
     pub fn try_new() -> Option<MidiSynth> {
         Some(MidiSynth {})
     }
+    pub fn init_channels(&self, _settings: &MidiSettings, state: &MidiState) {
+        for channel in state.channels.iter() {
+            if channel.track.is_some() {
+                init_channel(channel.channel.into(), channel.program.into());
+            }
+        }
+        load_instruments();
+    }
     pub fn send(&self, speed: &PlaySpeed, msg: &MidiMessage) -> Result<(), String> {
         match msg.midi {
             StructuredShortMessage::NoteOff {
@@ -22,8 +30,10 @@ impl MidiSynth {
                 key_number,
                 velocity,
             } => Ok(play_note(
+                channel.into(),
                 key_number.into(),
                 speed.calc_seconds(msg.entry.tied_units()),
+                u8::from(velocity) as f32 / 128.0,
             )),
             _ => Err("NOT_IMPLEMENTED".to_owned()),
         }
@@ -33,5 +43,17 @@ impl MidiSynth {
 #[wasm_bindgen]
 extern "C" {
     #[wasm_bindgen(js_namespace = window)]
-    fn play_note(seminones: u8, seconds: f32);
+    fn init_channel(channel: u8, program: u8);
+}
+
+#[wasm_bindgen]
+extern "C" {
+    #[wasm_bindgen(js_namespace = window)]
+    fn load_instruments();
+}
+
+#[wasm_bindgen]
+extern "C" {
+    #[wasm_bindgen(js_namespace = window)]
+    fn play_note(channel: u8, seminones: u8, seconds: f32, volume: f32);
 }