examples/camera.html

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<html>
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    <!--

    @license twgl.js Copyright (c) 2015, Gregg Tavares All Rights Reserved.
    Available via the MIT license.
    see: http://github.com/greggman/twgl.js for details

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    <meta property="og:title" content="TWGL.js - camera" />
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    <meta property="og:image" content="http://twgljs.org/examples/screenshots/camera.png" />
    <meta property="og:description" content="TWGL.js - camera" />
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    <link href="/resources/images/twgljs-icon.png" rel="shortcut icon" type="image/png">

    <title>twgl.js - camera</title>
    <style>
      body {
          margin: 0;
          font-family: monospace;
      }
      canvas {
          display: block;
          width: 100vw;
          height: 100vh;
      }
      #b {
        position: absolute;
        top: 10px;
        width: 100%;
        text-align: center;
        z-index: 2;
      }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
    <div id="b"><a href="http://twgljs.org">twgl.js</a> - camera</div>
  </body>
  <script id="vs" type="notjs">
uniform mat4 u_worldViewProjection;

attribute vec4 a_position;
attribute vec2 a_texcoord;

varying vec2 v_texCoord;

void main() {
  v_texCoord = a_texcoord;
  gl_Position = u_worldViewProjection * a_position;
}
  </script>
  <script id="fs" type="notjs">
precision mediump float;

varying vec2 v_texCoord;

uniform sampler2D u_diffuse;

void main() {
  gl_FragColor = texture2D(u_diffuse, v_texCoord);
}
  </script>
  <script src="../3rdparty/chroma.min.js"></script>
  <script type="module">
    import * as twgl from '../dist/6.x/twgl-full.module.js';

    let playing = false;
    const video = document.createElement("video");
    video.autoPlay = true;
    if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
        navigator.mediaDevices.getUserMedia({ video: true })
        .then(function(stream) {
            video.addEventListener('playing', () => {
                playing = true;
            });
            video.srcObject = stream;
            video.onloadedmetadata = () => {
                video.play();
            };
        })
        .catch(function(error) {
          console.error(error); // eslint-disable-line
        });
    }

    twgl.setDefaults({attribPrefix: "a_"});
    const m4 = twgl.m4;
    const gl = document.querySelector("#c").getContext("webgl");
    const programInfo = twgl.createProgramInfo(gl, ["vs", "fs"]);

    const shapes = [
      twgl.primitives.createCubeBufferInfo(gl, 2),
    ];

    function rand(min, max) {
      return min + Math.random() * (max - min);
    }

    // Shared values
    const camera = m4.identity();
    const view = m4.identity();
    const viewProjection = m4.identity();
    const world = m4.identity();

    const tex = twgl.createTexture(gl, {
      minMag: gl.LINEAR,
      wrap: gl.CLAMP_TO_EDGE,
      src: [
        255, 255, 255, 255,
        192, 192, 192, 255,
        192, 192, 192, 255,
        255, 255, 255, 255,
      ],
    });

    const objects = [];
    const drawObjects = [];
    const numObjects = 100;
    for (let ii = 0; ii < numObjects; ++ii) {
      const uniforms = {
        u_diffuse: tex,
        u_worldViewProjection: m4.identity(),
      };
      drawObjects.push({
        programInfo: programInfo,
        bufferInfo: shapes[ii % shapes.length],
        uniforms: uniforms,
      });
      objects.push({
        translation: [rand(-5, 5), rand(-5, 5), rand(-5, 5)],
        ySpeed: rand(0.1, 0.3),
        zSpeed: rand(0.1, 0.3),
        uniforms: uniforms,
      });
    }

    function render(time) {
      time *= 0.001;
      twgl.resizeCanvasToDisplaySize(gl.canvas);
      gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);

      gl.enable(gl.DEPTH_TEST);
      gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

      if (playing) {
        gl.bindTexture(gl.TEXTURE_2D, tex);
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, video);
      }

      const projection = m4.perspective(30 * Math.PI / 180, gl.canvas.clientWidth / gl.canvas.clientHeight, 0.5, 100);
      const eye = [1, 2, -10];
      const target = [0, 0, 0];
      const up = [0, 1, 0];

      m4.lookAt(eye, target, up, camera);
      m4.inverse(camera, view);
      m4.multiply(projection, view, viewProjection);

      objects.forEach(function(obj) {
        const uni = obj.uniforms;
        m4.identity(world);
        m4.rotateY(world, time * obj.ySpeed, world);
        m4.rotateZ(world, time * obj.zSpeed, world);
        m4.translate(world, obj.translation, world);
        m4.rotateX(world, time, world);
        m4.multiply(viewProjection, world, uni.u_worldViewProjection);
      });

      twgl.drawObjectList(gl, drawObjects);

      requestAnimationFrame(render);
    }
    requestAnimationFrame(render);

  </script>
</html>