dom/canvas/test/webgl-conf/checkout/conformance/attribs/gl-vertex-attrib-zero-issues.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>WebGL Enable Vertex Attrib Zero 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="50" height="50">
  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     void main()
  31     {
  32         gl_FragColor = vec4(0.0,1.0,0.0,1.0);
  33     }
  34 </script>
  35
  36 <script>
  37 "use strict";
  38 description("Test some of the issues of the difference between attrib 0 on OpenGL vs WebGL");
  39 debug("");
  40 var wtu = WebGLTestUtils;
  41 var gl = wtu.create3DContext("example");
  42 var g_program;
  43 var g_attribLocation;
  44 function setup(attribIndex) {
  45   var program = wtu.setupProgram(
  46       gl, ['vshader', 'fshader'], ['vPosition'], [attribIndex]);
  47   g_program = program;
  48   g_attribLocation = attribIndex;
  49   shouldBe("g_attribLocation", "gl.getAttribLocation(g_program, 'vPosition')");
  50   return program;
  51 }
  52
  53 function setupVerts(numVerts) {
  54   var verts = [
  55      1.0,  1.0, 0.0,
  56     -1.0,  1.0, 0.0,
  57     -1.0, -1.0, 0.0,
  58      1.0,  1.0, 0.0,
  59     -1.0, -1.0, 0.0,
  60      1.0, -1.0, 0.0
  61   ];
  62   var positions = new Float32Array(numVerts * 3);
  63   var indices = new Uint16Array(numVerts);
  64   for (var ii = 0; ii < numVerts; ++ii) {
  65     var ndx = ii % 6;
  66     var dst = ii * 3;
  67     var src = ndx * 3;
  68     for (var jj = 0; jj < 3; ++jj) {
  69       positions[dst + jj] = verts[src + jj];
  70     }
  71     indices[ii] = ii;
  72   }
  73   var vertexObject = gl.createBuffer();
  74   gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
  75   gl.bufferData(gl.ARRAY_BUFFER, positions, gl.STATIC_DRAW);
  76   var indexBuffer = gl.createBuffer();
  77   gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuffer);
  78   gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
  79 }
  80
  81 var p0 = setup(0);
  82 var p3 = setup(3);
  83 setupVerts(60000);
  84
  85 for (var ii = 0; ii < 5; ++ii) {
  86   // test drawing with attrib 0
  87   gl.useProgram(p0);
  88   gl.enableVertexAttribArray(0);
  89   gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
  90   gl.clear(gl.COLOR_BUFFER_BIT);
  91   gl.drawElements(gl.TRIANGLES, 60000, gl.UNSIGNED_SHORT, 0);
  92   wtu.glErrorShouldBe(
  93       gl, gl.NO_ERROR,
  94       "drawing using attrib 0 with 6 verts");
  95   wtu.checkCanvas(gl, [0, 255, 0, 255], "canvas should be green");
  96   gl.disableVertexAttribArray(0);
  97
  98   // test drawing without attrib 0
  99   gl.useProgram(p3);
 100   gl.enableVertexAttribArray(3);
 101   gl.vertexAttribPointer(3, 3, gl.FLOAT, false, 0, 0);
 102   gl.clear(gl.COLOR_BUFFER_BIT);
 103   gl.drawArrays(gl.TRIANGLES, 0, 60000);
 104   wtu.glErrorShouldBe(
 105       gl, gl.NO_ERROR,
 106       "drawing using attrib 3 with 60000 verts");
 107   wtu.checkCanvas(gl, [0, 255, 0, 255], "canvas should be green");
 108   gl.disableVertexAttribArray(3);
 109
 110   // This second test of drawing without attrib0 uncovered a bug in chrome
 111   // where after the draw without attrib0 the attrib 0 emulation code disabled
 112   // attrib 0 and it was never re-enabled so this next draw failed.
 113   gl.useProgram(p3);
 114   gl.enableVertexAttribArray(3);
 115   gl.clear(gl.COLOR_BUFFER_BIT);
 116   gl.drawElements(gl.TRIANGLES, 60000, gl.UNSIGNED_SHORT, 0);
 117   wtu.glErrorShouldBe(
 118       gl, gl.NO_ERROR,
 119       "drawing using attrib 3 with 60000 verts");
 120   wtu.checkCanvas(gl, [0, 255, 0, 255], "canvas should be green");
 121   gl.disableVertexAttribArray(3);
 122 }
 123
 124
 125 var successfullyParsed = true;
 126 </script>
 127 <script src="../../js/js-test-post.js"></script>
 128
 129 </body>
 130 </html>
 131