dom/canvas/test/webgl-conf/checkout/conformance/rendering/negative-one-index.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>-1 Index Rendering 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 function init()
  39 {
  40     description(document.title);
  41
  42     var wtu = WebGLTestUtils;
  43     var gl = wtu.create3DContext("example");
  44     var contextVersion = wtu.getDefault3DContextVersion();
  45     var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["vPosition"]);
  46
  47     var vertexObject = gl.createBuffer();
  48     gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
  49     var vertexData = new Float32Array(65536 * 3);
  50     vertexData[0 * 3 + 0] = 0.0;
  51     vertexData[0 * 3 + 1] = 0.5;
  52     vertexData[0 * 3 + 2] = 0.0;
  53     vertexData[1 * 3 + 0] = -0.5;
  54     vertexData[1 * 3 + 1] = -0.5;
  55     vertexData[1 * 3 + 2] = 0.0;
  56     vertexData[65535 * 3 + 0] = 0.5;
  57     vertexData[65535 * 3 + 1] = -0.5;
  58     vertexData[65535 * 3 + 2] = 0.0;
  59     gl.bufferData(gl.ARRAY_BUFFER, vertexData, gl.STATIC_DRAW);
  60     gl.enableVertexAttribArray(0);
  61     gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
  62
  63     var indices = new Uint16Array([0, 1, -1]);
  64     var indexBuffer = gl.createBuffer();
  65     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuffer);
  66     gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
  67
  68     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
  69     gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_SHORT, 0);
  70
  71     if (contextVersion <= 1) {
  72         // This should render a green triangle in the middle of the canvas.
  73         // Some implementations may incorrectly interpret the -1 index as
  74         // a primitive restart and not render anything.
  75
  76         // Test several locations
  77         // First line should be all black
  78         wtu.checkCanvasRect(gl, 0, 0, 50, 1, [0, 0, 0, 0]);
  79
  80         // Line 15 should be green for at least 10 pixels starting from row 20
  81         wtu.checkCanvasRect(gl, 20, 15, 10, 1, [0, 255, 0, 255]);
  82
  83         // Last line should be all black
  84         wtu.checkCanvasRect(gl, 0, 49, 50, 1, [0, 0, 0, 0]);
  85     } else {
  86         // For WebGL 2, PRIMITIVE_RESTART_FIXED_INDEX is always enabled.
  87         // Nothing should be drawn on the canvas.
  88         wtu.checkCanvasRect(gl, 0, 0, 50, 50, [0, 0, 0, 0]);
  89     }
  90 }
  91
  92 init();
  93 var successfullyParsed = true;
  94 </script>
  95 <script src="../../js/js-test-post.js"></script>
  96
  97 </body>
  98 </html>