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57 lines
2.1 KiB
Markdown
57 lines
2.1 KiB
Markdown
### Web MIDI
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#### Experimental!
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Hydra can be used with [Web MIDI](https://webaudio.github.io/web-midi-api/) for an extra layer of control to your visuals. At this time this requires some running of code on the
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browser console (Press F12 in Chrome to access). This page only considers MIDI Continuous Controllers (CC) but other types of data may be accessible.
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This is a generic script that doesn't care what Midi Channel you're broadcasting on and maps a normalized value 0.0-1.0 into an array named cc.
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### Console Script
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This portion should be ran in the console & will register Web MIDI & map the incoming CC data to a set of parameters. For simplicity, these
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parameters are named to match the CC number. The CC values are normally in a range from 0-127, but we've also normalized them to be in a range of 0.0-1.0.
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```
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// register WebMIDI
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navigator.requestMIDIAccess()
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.then(onMIDISuccess, onMIDIFailure);
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function onMIDISuccess(midiAccess) {
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console.log(midiAccess);
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var inputs = midiAccess.inputs;
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var outputs = midiAccess.outputs;
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for (var input of midiAccess.inputs.values()){
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input.onmidimessage = getMIDIMessage;
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}
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}
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function onMIDIFailure() {
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console.log('Could not access your MIDI devices.');
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}
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//create an array to hold our cc values and init to a normalized value
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var cc=Array(128).fill(0.5)
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getMIDIMessage = function(midiMessage) {
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var arr = midiMessage.data
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var index = arr[1]
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//console.log('Midi received on cc#' + index + ' value:' + arr[2]) // uncomment to monitor incoming Midi
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var val = (arr[2]+1)/128.0 // normalize CC values to 0.0 - 1.0
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cc[index]=val
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}
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```
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### Hydra script
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Now that these controls have been assigned to the cc[] array, we can start using them in Hydra. As we've normalized the values 0-1 we can use
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as-is with most functions or quickly remap them with various math.
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```
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// example midi mappings - Korg NanoKontrol2 CCs
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// color controls with first three knobs
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noise(4).color( ()=>cc[16], ()=>cc[17], ()=>cc[18] ).out()
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// rotate & scale with first two faders
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osc(10,0.2,0.5).rotate( ()=>(cc[0]*6.28)-3.14 ).scale( ()=>(cc[1]) ).out()
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```
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