test_vertexattrib4f_update.html

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<html>

  <head>

    <meta charset='utf-8'>

    <title>Bug 1426289 - vertexAttrib4f should actually update.</title>

    <script src='/tests/SimpleTest/SimpleTest.js'></script>

    <link rel='stylesheet' href='/tests/SimpleTest/test.css'>

    <script src='webgl-util.js'></script>

  </head>

  <body>

    <script id='eVertSource' type='none'>

attribute vec4 aColor;

varying vec4 vColor;

void main() {

  gl_PointSize = 64.0;

  gl_Position = vec4(vec3(0.0), 1.0);

  vColor = aColor;

    </script>

    <script id='eFragSource' type='none'>

precision mediump float;

varying vec4 vColor;

void main() {

  gl_FragColor = vColor;

    </script>

    <script>

const canvas = document.createElement('canvas');

canvas.width = 1;

canvas.height = 1;

const gl = canvas.getContext('webgl');

const prog = WebGLUtil.linkProgramByIds(gl, eVertSource, eFragSource);

gl.useProgram(prog);

function getRgb() {

  const data = new Uint32Array(1);

  gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, new Uint8Array(data.buffer));

  return data[0] & 0xffffff;

gl.clearColor(0.0, 0.0, 0.0, 1.0);

gl.clear(gl.COLOR_BUFFER_BIT);

let was = getRgb();

ok(was == 0x000000, '0x'+was.toString(16));

gl.disableVertexAttribArray(prog.aColor);

gl.vertexAttrib4f(prog.aColor, 1, 0, 0, 1);

gl.drawArrays(gl.POINTS, 0, 1);

was = getRgb();

ok(was == 0x0000ff, '0x'+was.toString(16));

gl.vertexAttrib4f(prog.aColor, 0, 1, 0, 1);

gl.drawArrays(gl.POINTS, 0, 1);

was = getRgb();

ok(was == 0x00ff00, '0x'+was.toString(16));

    </script>

  </body>

</html>