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: "Extention 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 +1,182 @@
+// Name: Midi Devices
+// ID: mididevicesjhub7682
+// Description: An extention that exposes MIDI devices
+// By: Jhub7682
+// License: MIT AND LGPL-3.0
+
+// Version V.1
+
+let lastNote = 0;
+let lastVelocity = 0;
+let pressedNotes = new Set();
+let pitchBendValue = 0;
+let controlValues = new Map();
+let programNumber = 0;
+let aftertouchValue = 0;
+let polyAftertouchValues = new Map();
+let midiDeviceName = "None";
+
+navigator.requestMIDIAccess()
+  .then((midiAccess) => {
+    for (let input of midiAccess.inputs.values()) {
+      midiDeviceName = input.name;
+
+      input.onmidimessage = (msg) => {
+        const [status, data1, data2] = msg.data;
+        const command = status & 0xF0;
+
+        switch (command) {
+          case 0x90: // Note On
+            if (data2 > 0) {
+              lastNote = data1;
+              lastVelocity = data2;
+              pressedNotes.add(data1);
+            } else {
+              pressedNotes.delete(data1); // Note Off via velocity 0
+            }
+            break;
+
+          case 0x80: // Note Off
+            pressedNotes.delete(data1);
+            break;
+
+          case 0xB0: // Control Change
+            controlValues.set(data1, data2);
+            break;
+
+          case 0xC0: // Program Change
+            programNumber = data1;
+            break;
+
+          case 0xD0: // Channel Pressure (Aftertouch)
+            aftertouchValue = data1;
+            break;
+
+          case 0xE0: // Pitch Bend
+            pitchBendValue = ((data2 << 7) | data1) - 8192;
+            break;
+
+          case 0xA0: // Polyphonic Aftertouch
+            polyAftertouchValues.set(data1, data2);
+            break;
+        }
+      };
+    }
+
+    Scratch.extensions.register({
+      getInfo() {
+        return {
+          id: "MDjhub7682",
+          name: "Midi Devices",
+          color1: "#ff6363ff",
+          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"
+            }
+          ]
+        };
+      },
+
+      midiNoteOn() {
+        return lastNote;
+      },
+
+      midiVelocity() {
+        return lastVelocity;
+      },
+
+      anyNotePressed() {
+        return pressedNotes.size > 0;
+      },
+
+      getCCValue(args) {
+        return controlValues.get(Number(args.CCNUM)) || 0;
+      },
+
+      getPitchBend() {
+        return pitchBendValue;
+      },
+
+      getProgramNumber() {
+        return programNumber;
+      },
+
+      getAftertouch() {
+        return aftertouchValue;
+      },
+
+      getPolyAftertouch(args) {
+        return polyAftertouchValues.get(Number(args.NOTE)) || 0;
+      },
+
+      getDeviceName() {
+        return midiDeviceName;
+      },
+
+      midiOctave() {
+        return Math.floor(lastNote / 12) - 1;
+      }
+    });
+  })
+  .catch((err) => {
+    console.error("MIDI access error:", err);
+  });