Extension Submission - "MIDI Devices"

src/lib/extensions.js

@@ -453,6 +453,14 @@ export default [
         creatorAlias: "gaimerI17",
         note: "Extension thumbnail made by Dillon."
     },
+    {
+        name: "MIDI Devices",
+        description: "Extension for exposing MIDI devices.",
+        code: "jhub7682/MIDIdevices.js",
+        banner: "jhub7682/MIDI_devices_extention.png",
+        creator: "Jhub7682",
+        isGitHub: true,
+    },
     /* these extensions are completely dead as of now
     {
         name: "Online Captcha",

static/extensions/jhub7682/MIDIdevices.js

@@ -0,0 +1,212 @@
+// Name: Midi Devices
+// ID: jhub7682MidiDevices
+// Description: An extension that exposes MIDI devices
+// By: Jhub7682
+// License: MIT AND LGPL-3.0
+// Version: V.2
+
+class MidiDevicesExtension {
+  constructor() {
+    this.lastNote = 0;
+    this.lastVelocity = 0;
+    this.pressedNotes = new Set();
+    this.noteVelocities = new Map();
+    this.pitchBendValue = 0;
+    this.controlValues = new Map();
+    this.programNumber = 0;
+    this.aftertouchValue = 0;
+    this.polyAftertouchValues = new Map();
+    this.midiDeviceName = "None";
+
+    this.initializeMIDI();
+  }
+
+  initializeMIDI() {
+    navigator.requestMIDIAccess()
+      .then((midiAccess) => {
+        for (let input of midiAccess.inputs.values()) {
+          this.midiDeviceName = input.name;
+
+          input.onmidimessage = (msg) => {
+            const [status, data1, data2] = msg.data;
+            const command = status & 0xF0;
+
+            switch (command) {
+              case 0x90:
+                if (data2 > 0) {
+                  this.lastNote = data1;
+                  this.lastVelocity = data2;
+                  this.pressedNotes.add(data1);
+                  this.noteVelocities.set(data1, data2);
+                } else {
+                  this.pressedNotes.delete(data1);
+                  this.noteVelocities.delete(data1);
+                }
+                break;
+
+              case 0x80:
+                this.pressedNotes.delete(data1);
+                this.noteVelocities.delete(data1);
+                break;
+
+              case 0xB0:
+                this.controlValues.set(data1, data2);
+                break;
+
+              case 0xC0:
+                this.programNumber = data1;
+                break;
+
+              case 0xD0:
+                this.aftertouchValue = data1;
+                break;
+
+              case 0xE0:
+                this.pitchBendValue = ((data2 << 7) | data1) - 8192;
+                break;
+
+              case 0xA0:
+                this.polyAftertouchValues.set(data1, data2);
+                break;
+            }
+          };
+        }
+      })
+      .catch((err) => {
+        console.error("MIDI access error:", err);
+      });
+  }
+
+  getInfo() {
+    return {
+      id: "jhub7682MidiDevices",
+      name: "Midi Devices",
+      color1: "#ff2c2cff",
+      blocks: [
+        {
+          opcode: "midiNoteOn",
+          blockType: "reporter",
+          text: "last MIDI note"
+        },
+        {
+          opcode: "midiVelocity",
+          blockType: "reporter",
+          text: "last velocity"
+        },
+        {
+          opcode: "anyNotePressed",
+          blockType: "reporter",
+          text: "MIDI note pressed?"
+        },
+        {
+          opcode: "getCCValue",
+          blockType: "reporter",
+          text: "CC [CCNUM] value",
+          arguments: {
+            CCNUM: {
+              type: "number",
+              defaultValue: 1
+            }
+          }
+        },
+        {
+          opcode: "getPitchBend",
+          blockType: "reporter",
+          text: "pitch bend value"
+        },
+        {
+          opcode: "getProgramNumber",
+          blockType: "reporter",
+          text: "program number"
+        },
+        {
+          opcode: "getAftertouch",
+          blockType: "reporter",
+          text: "aftertouch value"
+        },
+        {
+          opcode: "getPolyAftertouch",
+          blockType: "reporter",
+          text: "poly aftertouch for note [NOTE]",
+          arguments: {
+            NOTE: {
+              type: "number",
+              defaultValue: 60
+            }
+          }
+        },
+        {
+          opcode: "getDeviceName",
+          blockType: "reporter",
+          text: "MIDI device name"
+        },
+        {
+          opcode: "midiOctave",
+          blockType: "reporter",
+          text: "last MIDI octave"
+        },
+        {
+          opcode: "getPressedNotes",
+          blockType: "reporter",
+          text: "pressed notes array"
+        },
+        {
+          opcode: "getPressedVelocities",
+          blockType: "reporter",
+          text: "pressed velocities array"
+        }
+      ]
+    };
+  }
+
+  midiNoteOn() {
+    return this.lastNote;
+  }
+
+  midiVelocity() {
+    return this.lastVelocity;
+  }
+
+  anyNotePressed() {
+    return this.pressedNotes.size > 0;
+  }
+
+  getCCValue(args) {
+    return this.controlValues.get(Number(args.CCNUM)) || 0;
+  }
+
+  getPitchBend() {
+    return this.pitchBendValue;
+  }
+
+  getProgramNumber() {
+    return this.programNumber;
+  }
+
+  getAftertouch() {
+    return this.aftertouchValue;
+  }
+
+  getPolyAftertouch(args) {
+    return this.polyAftertouchValues.get(Number(args.NOTE)) || 0;
+  }
+
+  getDeviceName() {
+    return this.midiDeviceName;
+  }
+
+  midiOctave() {
+    return Math.floor(this.lastNote / 12) - 1;
+  }
+
+  getPressedNotes() {
+    return Array.from(this.pressedNotes).sort((a, b) => a - b);
+  }
+
+  getPressedVelocities() {
+
+    return this.getPressedNotes().map(note => this.noteVelocities.get(note) || 0);
+  }
+}
+
+Scratch.extensions.register(new MidiDevicesExtension());