From b5b866a89455f3a6a1d2e40afec22ec6ce9b598c Mon Sep 17 00:00:00 2001
From: Jade Rowland <jaderowlanddev@gmail.com>
Date: Sat, 19 Aug 2023 01:08:41 -0400
Subject: [PATCH] time clock improvements

---
 packages/midi/midi.mjs | 67 ++++++++++++++++++++++++------------------
 1 file changed, 39 insertions(+), 28 deletions(-)

diff --git a/packages/midi/midi.mjs b/packages/midi/midi.mjs
index 29abf21b..9d110b63 100644
--- a/packages/midi/midi.mjs
+++ b/packages/midi/midi.mjs
@@ -6,8 +6,8 @@ This program is free software: you can redistribute it and/or modify it under th
 
 import * as _WebMidi from 'webmidi';
 import { Pattern, isPattern, logger } from '@strudel.cycles/core';
-import { getAudioContext } from '@strudel.cycles/webaudio';
 import { noteToMidi } from '@strudel.cycles/core';
+import { Note } from 'webmidi';
 
 // if you use WebMidi from outside of this package, make sure to import that instance:
 export const { WebMidi } = _WebMidi;
@@ -47,7 +47,8 @@ export function enableWebMidi(options = {}) {
 // const outputByName = (name: string) => WebMidi.getOutputByName(name);
 const outputByName = (name) => WebMidi.getOutputByName(name);
 
-let midiReady;
+let midiReady = false;
+let prevTime = 0;
 
 // output?: string | number, outputs: typeof WebMidi.outputs
 function getDevice(output, outputs) {
@@ -60,7 +61,9 @@ function getDevice(output, outputs) {
   if (typeof output === 'string') {
     return outputByName(output);
   }
-  return outputs[0];
+  // attempt to default to IAC device if none is specified
+  const IACOutput = outputs.find((output) => output.name.includes('IAC'));
+  return IACOutput ?? outputs[0];
 }
 
 // Pattern.prototype.midi = function (output: string | number, channel = 1) {
@@ -68,21 +71,6 @@ Pattern.prototype.midi = function (output) {
   if (!supportsMidi()) {
     throw new Error(`🎹 WebMidi is not enabled. Supported Browsers: https://caniuse.com/?search=webmidi`);
   }
-  /* await */ enableWebMidi({
-    onConnected: ({ outputs }) =>
-      logger(`Midi device connected! Available: ${outputs.map((o) => `'${o.name}'`).join(', ')}`),
-    onDisconnected: ({ outputs }) =>
-      logger(`Midi device disconnected! Available: ${outputs.map((o) => `'${o.name}'`).join(', ')}`),
-    onReady: ({ outputs }) => {
-      const device = getDevice(output, outputs);
-      const otherOutputs = outputs
-        .filter((o) => o.name !== device.name)
-        .map((o) => `'${o.name}'`)
-        .join(' | ');
-      midiReady = true;
-      logger(`Midi connected! Using "${device.name}". ${otherOutputs ? `Also available: ${otherOutputs}` : ''}`);
-    },
-  });
   if (isPattern(output)) {
     throw new Error(
       `.midi does not accept Pattern input. Make sure to pass device name with single quotes. Example: .midi('${
@@ -90,11 +78,34 @@ Pattern.prototype.midi = function (output) {
       }')`,
     );
   }
-  return this.onTrigger((time, hap) => {
+
+  if (midiReady === false) {
+    enableWebMidi({
+      onConnected: ({ outputs }) => {
+        const device = getDevice(output, outputs);
+        const otherOutputs = outputs
+          .filter((o) => o.name !== device.name)
+          .map((o) => `'${o.name}'`)
+          .join(' | ');
+
+        midiReady = true;
+        logger(`Midi connected! Using "${device.name}". ${otherOutputs ? `Also available: ${otherOutputs}` : ''}`);
+      },
+      onDisconnected: ({ outputs }) =>
+        logger(`Midi device disconnected! Available: ${outputs.map((o) => `'${o.name}'`).join(', ')}`),
+    });
+  }
+
+  return this.onTrigger((time, hap, currentTime, cps = 1) => {
     if (!midiReady) {
       return;
     }
+
     const device = getDevice(output, WebMidi.outputs);
+    const current = performance.now();
+    // console.log(current - prevTime);
+    prevTime = current;
+
     if (!device) {
       throw new Error(
         `🔌 MIDI device '${output ? output : ''}' not found. Use one of ${WebMidi.outputs
@@ -104,21 +115,21 @@ Pattern.prototype.midi = function (output) {
     }
     hap.ensureObjectValue();
 
-    // calculate time
-    const timingOffset = WebMidi.time - getAudioContext().getOutputTimestamp().contextTime * 1000;
-    time = time * 1000 + timingOffset;
+    const offset = (time - currentTime) * 1000;
+
+    // passing a string with a +num into the webmidi api adds an offset to the current time https://webmidijs.org/api/classes/Output
+    const timeOffsetString = `+${offset}`;
 
     // destructure value
     const { note, nrpnn, nrpv, ccn, ccv, midichan = 1 } = hap.value;
     const velocity = hap.context?.velocity ?? 0.9; // TODO: refactor velocity
-    const duration = hap.duration.valueOf() * 1000 - 5;
+    const duration = Math.round(hap.duration.valueOf() * 1000 - 5);
 
     if (note != null) {
       const midiNumber = typeof note === 'number' ? note : noteToMidi(note);
-      device.playNote(midiNumber, midichan, {
-        time,
-        duration,
-        attack: velocity,
+      const midiNote = new Note(midiNumber, { attack: velocity, duration });
+      device.playNote(midiNote, midichan, {
+        time: timeOffsetString,
       });
     }
     if (ccv && ccn) {
@@ -129,7 +140,7 @@ Pattern.prototype.midi = function (output) {
         throw new Error('expected ccn to be a number or a string');
       }
       const scaled = Math.round(ccv * 127);
-      device.sendControlChange(ccn, scaled, midichan, { time });
+      device.sendControlChange(ccn, scaled, midichan, { time: timeOffsetString });
     }
   });
 };