dom/canvas/test/webgl-conf/checkout/conformance/glsl/variables/gl-fragcoord.html

   1 <!--
   2 Copyright (c) 2019 The Khronos Group Inc.
   3 Use of this source code is governed by an MIT-style license that can be
   4 found in the LICENSE.txt file.
   5 -->
   6
   7 <!DOCTYPE html>
   8 <html>
   9 <head>
  10 <meta charset="utf-8">
  11 <title>gl-fragcoord Test</title>
  12 <link rel="stylesheet" href="../../../resources/js-test-style.css"/>
  13 <script src="../../../js/js-test-pre.js"></script>
  14 <script src="../../../js/webgl-test-utils.js"> </script>
  15 </head>
  16 <body>
  17 <canvas id="example" width="32" height="32">
  18 </canvas>
  19 <div id="description"></div>
  20 <div id="console"></div>
  21 <script id="vshader" type="x-shader/x-vertex">
  22 attribute vec4 vPosition;
  23 void main()
  24 {
  25   gl_Position = vPosition;
  26 }
  27 </script>
  28
  29 <script id="fshader" type="x-shader/x-fragment">
  30 precision mediump float;
  31 void main()
  32 {
  33   gl_FragColor = vec4(
  34       floor(gl_FragCoord.x * 4.0 / 32.0) / 4.0,
  35       floor(gl_FragCoord.y * 4.0 / 32.0) / 4.0,
  36       floor(gl_FragCoord.z * 4.0) / 4.0,
  37       1);
  38 }
  39 </script>
  40
  41 <script>
  42 "use strict";
  43 function init()
  44 {
  45   description("tests gl_FragCoord");
  46
  47   var wtu = WebGLTestUtils;
  48   var gl = wtu.create3DContext("example");
  49   var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["vPosition"]);
  50
  51   var vertexObject = gl.createBuffer();
  52   gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
  53   gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(
  54       [-1, -1, -1,  1, -1,  0, -1,  1,  0,
  55        -1,  1,  0,  1, -1,  0,  1,  1,  1]),
  56       gl.STATIC_DRAW);
  57   gl.enableVertexAttribArray(0);
  58   gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
  59
  60   gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
  61   gl.drawArrays(gl.TRIANGLES, 0, 6);
  62   wtu.glErrorShouldBe(gl, gl.NO_ERROR, "no errors from draw");
  63
  64   for (var xx = 0; xx < 32; xx += 4) {
  65     for (var yy = 0; yy < 32; yy += 4) {
  66       var zz = (xx / 64) + (yy / 64);
  67       var color = [
  68         Math.floor(Math.floor(xx * 4.0 / 32.0) / 4 * 256),
  69         Math.floor(Math.floor(yy * 4.0 / 32.0) / 4 * 256),
  70         Math.floor(Math.floor(zz * 4.0) / 4 * 256)
  71       ];
  72       var msg = "should be " + color;
  73       wtu.checkCanvasRect(gl, xx, yy, 1, 1, color, msg, 4);
  74     }
  75   }
  76 }
  77
  78 init();
  79 var successfullyParsed = true;
  80 </script>
  81 <script src="../../../js/js-test-post.js"></script>
  82
  83 </body>
  84 </html>