New chorus

- sf2 compliant chorus (respects the generators)
- maintaining legacy system
- the synth will now use the legacy system if the website is served over insecure context
- update README accordingly
- finally added the event system to the documentation

README.md

@@ -19,6 +19,7 @@ SoundFont2 based realtime synthetizer and MIDI player written in JavaScript usin
 - Reverb and chorus support
 - A few custom modulators to support some additional controllers (see `modulators.js`)
 - Written using AudioWorklets (Firefox and Chrome both work perfectly)
+- Legacy system that doesn't use AudioWorklets (Available to use over HTTP and will switch automatically)
 - Can load really large soundfonts (4GB!) (but only on Firefox, Chromium has a memory limit)
 - Multi-port MIDIs support (more than 16 channels)
 - MIDI Controller Support (Default supported controllers can be found [here](../../wiki/Synthetizer-Class#supported-controllers))
@@ -37,6 +38,8 @@ SoundFont2 based realtime synthetizer and MIDI player written in JavaScript usin
 
 ### Limitations
 - It might not sound as good as other synthetizers (e.g. FluidSynth or BASSMIDI)
+- The modulation envelope needs some work
+- the modulators need some work
 
 ## Installation
 ***When you're loading a large (>4GB) SoundFont, use Firefox because chromium has a 4GB memory limit***
@@ -77,6 +80,8 @@ The program is divided into parts:
 #### todo
 - make the worklet system perform good
 - port the worklet system to emscripten (maybe)
-- 
+- fix modenv
+- fix rare clicking in volenv
+- fix attenuation modulators
 ### License
 Copyright © 2024 Spessasus. Licensed under the MIT License.

src/spessasynth_lib/soundfont/chunk/modulators.js

@@ -122,6 +122,9 @@ export const defaultModulators = [
     // reverb effects to send
     new Modulator({srcEnum: 0x00DB, dest: generatorTypes.reverbEffectsSend, amt: 500, secSrcEnum: 0x0, transform: 0}),
 
+    // chorus effects to send
+    new Modulator({srcEnum: 0x00DD, dest: generatorTypes.chorusEffectsSend, amt: 200, secSrcEnum: 0x0, transform: 0}),
+
     // custom modulators heck yeah
     // cc 92 (tremolo) to modLFO volume
     new Modulator({

src/spessasynth_lib/synthetizer/fancy_chorus.js

@@ -0,0 +1,41 @@
+const DEFAULT_DELAY = 0.02;
+const DELAY_VARIATION = 0.015;
+
+const OSC_FREQ = 1.5;
+const OSC_GAIN = 0.001;
+export class FancyChorus
+{
+    /**
+     * @param output {AudioNode}
+     */
+    constructor(output) {
+        const context = output.context;
+
+        this.input = new GainNode(context,
+            {
+                gain: 1
+            });
+
+        const osc = new OscillatorNode(context, {
+            type: 'sine',
+            frequency: OSC_FREQ
+        });
+
+        const oscGain = new GainNode(context, {
+            gain: OSC_GAIN
+        });
+        osc.connect(oscGain);
+        osc.start();
+        const delayOne = new DelayNode(context, {
+            delayTime: DEFAULT_DELAY
+        });
+        const delayTwo = new DelayNode(context, {
+            delayTime: DEFAULT_DELAY + DELAY_VARIATION
+        });
+        oscGain.connect(delayOne.delayTime);
+        this.input.connect(delayOne);
+        this.input.connect(delayTwo);
+        delayTwo.connect(output);
+        delayOne.connect(output);
+    }
+}

src/spessasynth_lib/synthetizer/native_system/README.md

@@ -1,25 +1,15 @@
 # This is the old synthesis system.
-It's not maintained anymore, but it's here for the HTTP websites which can't use AudioWorklets.
-To use this system, edit `synthetizer.js`:
+It's not updated anymore, but it's here for the HTTP websites which can't use AudioWorklets.
+To use this system, change the `synthesisMode` to `"legacy"`:
+
 ```js
-import { MidiChannel } from './native_system/midi_channel.js';
+synth.synthesisMode = "legacy";
 ```
-and change the class from `WorkletChannel` to `MidiChannel`
+it should automatically create the legacy channels.
+If you want to automatically use this mode, then
 ```js
-/**
- *  create 16 channels
- * @type {WorkletChannel[]|MidiChannel[]}
- */
-this.midiChannels = [...Array(DEFAULT_CHANNEL_COUNT).keys()].map(j => new MidiChannel(this.volumeController, this.defaultPreset, j + 1, false));
-
-// ...
+export const DEFAULT_SYNTHESIS_MODE = "legacy";
+```
 
-/**
- * Adds a new channel to the synthesizer
- */
-addNewChannel()
-{
-    this.midiChannels.push(new MidiChannel(this.volumeController, this.defaultPreset, this.midiChannels.length + 1, false));
-    this.eventHandler.callEvent("newchannel", this.midiChannels[this.midiChannels.length - 1]);
-}
-```
+Note:
+the synth will try to detect if the worklets are available. if not, then it should switch to legacy

src/spessasynth_lib/synthetizer/native_system/midi_channel.js

@@ -2,7 +2,6 @@ import {VoiceGroup} from "./voice_group.js";
 import {Preset} from "../../soundfont/chunk/presets.js";
 import { consoleColors } from '../../utils/other.js'
 import { midiControllers } from '../../midi_parser/midi_message.js'
-import { Chorus } from '../chorus.js'
 
 const CHANNEL_LOUDNESS = 0.3;
 
@@ -21,11 +20,12 @@ export class MidiChannel {
      * creates a midi channel
      * @param targetNode {AudioNode}
      * @param targetReverbNode {AudioNode}
+     * @param targetChorusNode {AudioNode}
      * @param defaultPreset {Preset}
      * @param channelNumber {number}
      * @param percussionChannel {boolean}
      */
-    constructor(targetNode, targetReverbNode, defaultPreset, channelNumber = -1, percussionChannel = false) {
+    constructor(targetNode, targetReverbNode, targetChorusNode, defaultPreset, channelNumber = -1, percussionChannel = false) {
         this.ctx = targetNode.context;
         this.outputNode = targetNode;
         this.channelNumber = channelNumber
@@ -65,12 +65,17 @@ export class MidiChannel {
         // note -> panner -> chorus -> gain -> reverb + passthrough)     -> out
 
         //const dummy = new GainNode(this.ctx, {gain: 1});
-        this.chorus = new Chorus(this.panner, this.gainController, 0);
+        this.chorus = new GainNode(this.ctx, {
+            gain: 0
+        });
+        this.chorus.connect(targetChorusNode)
         //this.reverb.input.connect(dummy);
         //this.reverb.connectOutput(this.gainController);
 
+        this.panner.connect(this.gainController);
         this.gainController.connect(this.outputNode);
         this.gainController.connect(this.reverb);
+        this.gainController.connect(this.chorus);
 
         this.resetControllers();
 
@@ -100,6 +105,18 @@ export class MidiChannel {
         this.lockVibrato = false;
     }
 
+    /**
+     * Kills the channel, disconnecting everything
+     */
+    killChannel()
+    {
+        this.gainController.disconnect();
+        this.stopAll(true);
+        this.muteChannel();
+        this.playingNotes = [];
+        this.stoppingNotes = [];
+    }
+
     /**
      * @param number {number}
      * @param value
@@ -335,7 +352,7 @@ export class MidiChannel {
      */
     setChorus(chorus)
     {
-        this.chorus.setChorusLevel(chorus);
+        this.chorus.gain.value = chorus / 127;
     }
 
     setReverb(reverbLevel)
@@ -578,11 +595,17 @@ export class MidiChannel {
 
     resetControllers()
     {
+        /**
+         * @type {number}
+         */
         this.channelVolume = 100 / 127; // per midi spec
+        /**
+         * @type {number}
+         */
         this.channelExpression = 1;
         this.channelTuningRatio = 1;
         this.channelPitchBendRange = 2;
-        this.chorus.setChorusLevel(0);
+        this.chorus.gain.value = 0;
         this.holdPedal = false;
         this.updateGain();
         this.panner.pan.value = 0;