dom/canvas/test/webgl-conf/checkout/conformance/rendering/draw-with-changing-start-vertex-bug.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 <!--
   8 This bug would occur after the app would render several times with the
   9 same vertex attributes and buffers, but using a different start offset.
  10 One of the buffers would likely have to be DYNAMIC.
  11
  12 See http://anglebug.com/1327 and http://crbug.com/594509
  13 -->
  14
  15 <!DOCTYPE html>
  16 <html>
  17 <head>
  18 <meta charset="utf-8">
  19 <title>Draw with changing start vertex test</title>
  20 <link rel="stylesheet" href="../../resources/js-test-style.css"/>
  21 <script src="../../js/js-test-pre.js"></script>
  22 <script src="../../js/webgl-test-utils.js"></script>
  23 </head>
  24 <body>
  25 <canvas id="canvas" width="16" height="16"> </canvas>
  26 <div id="description"></div>
  27 <div id="console"></div>
  28 <script id="vshader" type="x-shader/x-vertex">
  29 attribute mediump vec4 position;
  30 attribute mediump vec4 test;
  31 attribute mediump vec4 expected;
  32 varying mediump vec4 color;
  33 void main(void)
  34 {
  35     gl_Position = position;
  36     vec4 threshold = max(abs(expected) * 0.01, 1.0 / 64.0);
  37     color = vec4(lessThanEqual(abs(test - expected), threshold));
  38 }
  39 </script>
  40
  41 <script id="fshader" type="x-shader/x-fragment">
  42 varying mediump vec4 color;
  43 void main(void)
  44 {
  45     gl_FragColor = color;
  46 }
  47 </script>
  48
  49 <script>
  50 "use strict";
  51 description("Test calling drawArrays with repeatedly with a different start vertex");
  52
  53 var wtu = WebGLTestUtils;
  54 var canvas = document.getElementById("canvas1");
  55 var gl = wtu.create3DContext(canvas);
  56
  57 var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["position", "test", "expected"]);
  58
  59 var vertexCount = 24;
  60 var testData = new Float32Array(vertexCount);
  61
  62 for (var index = 0; index < vertexCount; ++index) {
  63     testData[index] = index;
  64 }
  65
  66 var quadData = new Float32Array(14)
  67 quadData[0] = -1.0; quadData[1] = 1.0;
  68 quadData[2] = -1.0; quadData[3] = -1.0;
  69 quadData[4] = 1.0;  quadData[5] = -1.0;
  70 quadData[6] = -1.0; quadData[7] = 1.0;
  71 quadData[8] = 1.0;  quadData[9] = -1.0;
  72 quadData[10] = 1.0; quadData[11] = 1.0;
  73 quadData[12] = 0.0; quadData[13] = 0.0;
  74
  75 var quadBuffer = gl.createBuffer();
  76 gl.bindBuffer(gl.ARRAY_BUFFER, quadBuffer);
  77 gl.bufferData(gl.ARRAY_BUFFER, quadData, gl.STATIC_DRAW);
  78 gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);
  79 gl.enableVertexAttribArray(0);
  80
  81 // Must be STATIC to trigger the bug.
  82 var testBuffer = gl.createBuffer();
  83 gl.bindBuffer(gl.ARRAY_BUFFER, testBuffer);
  84 gl.bufferData(gl.ARRAY_BUFFER, testData, gl.STATIC_DRAW);
  85 gl.vertexAttribPointer(1, 1, gl.FLOAT, false, 0, 0);
  86 gl.enableVertexAttribArray(1);
  87
  88 // Must be DYNAMIC to trigger the bug.
  89 var expectedBuffer = gl.createBuffer();
  90 gl.bindBuffer(gl.ARRAY_BUFFER, expectedBuffer);
  91 gl.bufferData(gl.ARRAY_BUFFER, testData, gl.DYNAMIC_DRAW);
  92 gl.vertexAttribPointer(2, 1, gl.FLOAT, false, 0, 0);
  93 gl.enableVertexAttribArray(2);
  94
  95 function check() {
  96     wtu.checkCanvas(gl, [255, 255, 255, 255], "should be white");
  97 }
  98
  99 gl.drawArrays(gl.TRIANGLES, 0, 6);
 100 check()
 101
 102 gl.drawArrays(gl.TRIANGLES, 0, 6);
 103 check()
 104
 105 gl.drawArrays(gl.TRIANGLES, 1, 6);
 106 check()
 107
 108 debug("");
 109 var successfullyParsed = true;
 110 </script>
 111
 112 <script src="../../js/js-test-post.js"></script>
 113 </body>
 114 </html>