dom/canvas/test/webgl-conf/checkout/conformance2/attribs/gl-vertex-attrib-normalized-int.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 <!DOCTYPE html>
   7 <html>
   8 <head>
   9     <title>WebGL 2 Normalized Vertex Attributes Conformance Test</title>
  10     <meta charset="utf-8">
  11     <link rel="stylesheet" href="../../resources/js-test-style.css"/>
  12 </head>
  13 <body>
  14     <canvas width=1 height=1></canvas>
  15     <div id="description"></div>
  16     <div id="console"></div>
  17     <script id="vertex-shader" type="x-shader/x-vertex">#version 300 es
  18         layout(location = 0) in vec3 vertex;
  19
  20         out float normAttrib;
  21
  22         void main(void) {
  23             gl_Position = vec4(vertex.xy, 0, 1);
  24             normAttrib = vertex.z;
  25         }
  26     </script>
  27     <script id="fragment-shader" type="x-shader/x-fragment">#version 300 es
  28         in lowp float normAttrib;
  29
  30         layout(location=0) out lowp vec4 fragColor;
  31
  32         void main(void) {
  33             fragColor = vec4(vec3(normAttrib == -1.0 ? 1.0 : 0.0), 1);
  34         }
  35     </script>
  36     <script src="../../js/js-test-pre.js"></script>
  37     <script src="../../js/webgl-test-utils.js"></script>
  38     <script>
  39         (function () {
  40             'use strict';
  41
  42             var wtu = WebGLTestUtils;
  43
  44             var gl = wtu.create3DContext(document.querySelector('canvas'), null, 2);
  45
  46             var program = wtu.setupProgram(gl, ['vertex-shader', 'fragment-shader']);
  47
  48             gl.useProgram(program);
  49
  50             var buffer = gl.createBuffer();
  51             gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
  52             gl.bufferData(gl.ARRAY_BUFFER, new Int8Array([
  53                 // Here we set the third component (the one that's actually tested)
  54                 // to (MIN_INT + 1). If non-zero-preserving rules are used, it'll be
  55                 // converted to a float that's slightly greater than -1. If zero-preserving
  56                 // rules are used, as the GLES 3 spec requires, result of conversion
  57                 // should be exactly -1.
  58                 -0x80,  0x7f, -0x7f,
  59                  0x7f,  0x7f, -0x7f,
  60                 -0x80, -0x7f, -0x7f,
  61                 -0x80, -0x7f, -0x7f,
  62                  0x7f,  0x7f, -0x7f,
  63                  0x7f, -0x80, -0x7f
  64             ]), gl.STATIC_DRAW);
  65
  66             gl.enableVertexAttribArray(0);
  67             gl.vertexAttribPointer(0, 3, gl.BYTE, true, 0, 0);
  68
  69             gl.drawArrays(gl.TRIANGLE_STRIP, 0, 6);
  70
  71             wtu.checkCanvas(gl, [255, 255, 255, 255], "should be opaque white");
  72         }());
  73     </script>
  74     <script>
  75         description('Verify that conversion of normalized signed int attributes to floats uses zero-preserving rule.');
  76         window.successfullyParsed = true;
  77     </script>
  78     <script src="../../js/js-test-post.js"></script>
  79 </body>
  80 </html>