47 lines
1.5 KiB
JavaScript
47 lines
1.5 KiB
JavaScript
class TransportProcessor extends AudioWorkletProcessor {
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constructor(options) {
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super(options);
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this.port.addEventListener("message", this.handleMessage);
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this.port.start();
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this.started = false;
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this.bpm = 120;
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this.ppqn = 48;
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this.currentPulsePosition = 0;
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}
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handleMessage = (message) => {
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if(message.data && message.data.type === "ping") {
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this.port.postMessage(message.data);
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} else if (message.data === "start") {
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this.started = true;
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} else if(message.data === "pause") {
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this.started = false;
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} else if(message.data === "stop") {
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this.started = false;
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} else if(message.data.type === 'bpm') {
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this.bpm = message.data.value;
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this.currentPulsePosition = 0;
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} else if(message.data.type === 'ppqn') {
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this.ppqn = message.data.value;
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this.currentPulsePosition = 0;
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}
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};
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process(inputs, outputs, parameters) {
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if (this.started) {
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const beatNumber = currentTime / (60 / this.bpm);
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const currentPulsePosition = Math.ceil(beatNumber * this.ppqn);
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if(currentPulsePosition > this.currentPulsePosition) {
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this.currentPulsePosition = currentPulsePosition;
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this.port.postMessage({ type: "bang" });
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}
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}
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return true;
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}
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}
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registerProcessor(
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"transport",
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TransportProcessor
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); |