examples/constant-attributes.html

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    <title>twgl.js - constant attributes</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> - constant attributes</div>
  </body>
  <script id="vs" type="notjs">
uniform mat4 u_worldViewProjection;

attribute vec4 position;
attribute vec4 color;

varying vec4 v_color;

void main() {
  gl_Position = u_worldViewProjection * position;
  v_color = color;
}
  </script>
  <script id="fs" type="notjs">
precision mediump float;

varying vec4 v_color;

void main() {
  gl_FragColor = v_color;
}
  </script>
  <script src="../dist/6.x/twgl-full.js"></script>
  <script type="module">
    import * as twgl from '../dist/6.x/twgl-full.module.js';
    const m4 = twgl.m4;
    const gl = document.querySelector("#c").getContext("webgl", { alpha: false });
    const programInfo = twgl.createProgramInfo(gl, ["vs", "fs"]);

    const redBufferInfo = twgl.createBufferInfoFromArrays(gl, {
      position: [
        -1, -1, 0,
         1, -1, 0,
        -1,  1, 0,
         1,  1, 0,
      ],
      color: { value: [1, 0, 0, 1], },
      indices:  [
        0, 1, 2,
        2, 1, 3,
      ],
    });
    const greenBufferInfo = twgl.createBufferInfoFromArrays(gl, {
      color: { value: [0, 1, 0, 1], },
    }, redBufferInfo);
    const blueBufferInfo = twgl.createBufferInfoFromArrays(gl, {
      color: { value: [0, 0, 1, 1], },
    }, redBufferInfo);
    const yellowBufferInfo = twgl.createBufferInfoFromArrays(gl, {
      color: { value: [1, 1, 0, 1], },
    }, redBufferInfo);


    const bufferInfos = [
      redBufferInfo,
      greenBufferInfo,
      blueBufferInfo,
      yellowBufferInfo,
    ];

    twgl.resizeCanvasToDisplaySize(gl.canvas);
    gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);

    gl.useProgram(programInfo.program);
    for (let i = 0; i < 100; ++i) {
      const bufferInfo = bufferInfos[r(bufferInfos.length) | 0];

      twgl.setBuffersAndAttributes(gl, programInfo, bufferInfo);

      let matrix = m4.translation([r(-1, 1), r(-1, 1), 0]);
      matrix = m4.scale(matrix, [0.1, 0.1, 0.1]);
      twgl.setUniforms(programInfo, {
        u_worldViewProjection: matrix,
      });
      twgl.drawBufferInfo(gl, bufferInfo);
    }

    function r(min, max) {
      if (max === undefined) {
        max = min;
        min = 0;
      }
      return min + Math.random() * (max - min);
    }

  </script>
</html>