groovebox-ruby/visualizer.html at main · asonas/groovebox-ruby · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Audio Waveform Visualizer</title>
  <style>
    body {
      margin: 0;
      overflow: hidden;
    }
    canvas {
      display: block;
      width: 100vw;
      height: 90vh;
    }
    #deviceSelector {
      position: absolute;
      top: 0;
      width: 100%;
      z-index: 10;
      background: white;
      padding: 10px;
    }
    select {
      font-size: 16px;
    }
  </style>
</head>
<body>
  <div id="deviceSelector">
    <label for="audioInput">Select Audio Input: </label>
    <select id="audioInput"></select>
  </div>
  <canvas id="glCanvas"></canvas>

  <script type="text/javascript">
    const canvas = document.getElementById("glCanvas");
    const gl = canvas.getContext("webgl");

    function resizeCanvas() {
      canvas.width = window.innerWidth;
      canvas.height = window.innerHeight * 0.9;
      gl.viewport(0, 0, canvas.width, canvas.height);
    }

    const vertexShaderSource = `
      attribute float aSample;
      attribute float aIndex;
      uniform float uResolution;
      uniform float uHeight;
      varying float vSample;

      void main() {
        vSample = aSample;
        float x = aIndex / uResolution * 2.0 - 1.0; // Normalize to [-1, 1]
        float y = aSample * uHeight; // Scale to canvas height
        gl_Position = vec4(x, y, 0.0, 1.0);
      }
    `;

    const fragmentShaderSource = `
      precision mediump float;
      varying float vSample;

      void main() {
        gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0); // Black color
      }
    `;

    function createShader(gl, type, source) {
      const shader = gl.createShader(type);
      gl.shaderSource(shader, source);
      gl.compileShader(shader);
      if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
        console.error("Shader compile failed with: " + gl.getShaderInfoLog(shader));
        gl.deleteShader(shader);
        return null;
      }
      return shader;
    }

    const vertexShader = createShader(gl, gl.VERTEX_SHADER, vertexShaderSource);
    const fragmentShader = createShader(gl, gl.FRAGMENT_SHADER, fragmentShaderSource);

    const program = gl.createProgram();
    gl.attachShader(program, vertexShader);
    gl.attachShader(program, fragmentShader);
    gl.linkProgram(program);
    if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
      console.error("Program failed to link: " + gl.getProgramInfoLog(program));
    }

    gl.useProgram(program);

    const resolution = 512; // Number of samples to visualize
    const samples = new Float32Array(resolution).fill(0);
    const indices = new Float32Array(resolution).map((_, i) => i);

    const aSample = gl.getAttribLocation(program, "aSample");
    const aIndex = gl.getAttribLocation(program, "aIndex");
    const uResolution = gl.getUniformLocation(program, "uResolution");
    const uHeight = gl.getUniformLocation(program, "uHeight");

    const sampleBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, sampleBuffer);
    gl.bufferData(gl.ARRAY_BUFFER, samples, gl.DYNAMIC_DRAW);
    gl.vertexAttribPointer(aSample, 1, gl.FLOAT, false, 0, 0);
    gl.enableVertexAttribArray(aSample);

    const indexBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, indexBuffer);
    gl.bufferData(gl.ARRAY_BUFFER, indices, gl.STATIC_DRAW);
    gl.vertexAttribPointer(aIndex, 1, gl.FLOAT, false, 0, 0);
    gl.enableVertexAttribArray(aIndex);

    gl.uniform1f(uResolution, resolution);

    const deviceSelector = document.getElementById("audioInput");

    async function updateDeviceList() {
      const devices = await navigator.mediaDevices.enumerateDevices();
      const audioDevices = devices.filter(device => device.kind === "audioinput");

      deviceSelector.innerHTML = ""; // Clear existing options
      audioDevices.forEach(device => {
        const option = document.createElement("option");
        option.value = device.deviceId;
        option.textContent = device.label || `Microphone ${device.deviceId}`;
        deviceSelector.appendChild(option);
      });
    }

    async function startAudio(deviceId) {
      const constraints = { audio: { deviceId: deviceId ? { exact: deviceId } : undefined } };
      const stream = await navigator.mediaDevices.getUserMedia(constraints);
      const audioContext = new AudioContext();
      const analyser = audioContext.createAnalyser();
      analyser.fftSize = resolution * 2;
      const audioData = new Float32Array(analyser.fftSize);

      const source = audioContext.createMediaStreamSource(stream);
      source.connect(analyser);

      function render() {
        analyser.getFloatTimeDomainData(audioData);
        samples.set(audioData.slice(0, resolution));
        gl.bindBuffer(gl.ARRAY_BUFFER, sampleBuffer);
        gl.bufferSubData(gl.ARRAY_BUFFER, 0, samples);

        gl.clear(gl.COLOR_BUFFER_BIT);
        gl.drawArrays(gl.LINE_STRIP, 0, resolution);

        requestAnimationFrame(render);
      }

      gl.clearColor(1.0, 1.0, 1.0, 1.0); // Set white background
      gl.uniform1f(uHeight, 1.0); // Normalize sample height to [-1, 1]
      render();
    }

    deviceSelector.addEventListener("change", () => {
      const selectedDeviceId = deviceSelector.value;
      startAudio(selectedDeviceId);
    });

    window.addEventListener("load", async () => {
      resizeCanvas(); // Adjust canvas size at load
      await updateDeviceList();
      const initialDeviceId = deviceSelector.value;
      startAudio(initialDeviceId);
    });

    window.addEventListener("resize", resizeCanvas); // Adjust canvas size on resize
  </script>
</body>
</html>