dom/canvas/test/webgl-conf/checkout/conformance/manual/canvas-clear-on-zero-count-draw.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>Check that the canvas is NOT recomposited after unsucessful draw call</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 <style>
  16 canvas {
  17     border: 1px solid black;
  18 }
  19 .correct {
  20     border: 1px solid black;
  21     background-color: #ffffff;
  22 }
  23 </style>
  24 </head>
  25 <body>
  26 <pre>
  27 This test must be run manually.
  28
  29 This test tests that a canvas is cleared
  30 even when a draw call has a zero count.
  31
  32 You should see three <span class="correct">white rectangles</span>
  33 with black outlines on success.
  34 </pre>
  35 <canvas id='c1'></canvas>
  36 <canvas id='c2'></canvas>
  37 <canvas id='c3'></canvas>
  38 <div id="console"></div>
  39 <script id="vshader" type="x-shader/x-vertex">
  40 void main() {
  41   gl_Position = vec4(0,0,0,1);
  42 }
  43 </script>
  44 <script id="fshader" type="x-shader/x-fragment">
  45 precision mediump float;
  46 void main() {
  47   discard;
  48 }
  49 </script>
  50 <script>
  51 "use strict";
  52 var wtu = WebGLTestUtils;
  53 var c1 = document.getElementById("c1");
  54 var c2 = document.getElementById("c2");
  55 var c3 = document.getElementById("c2");
  56 var gl1 = wtu.create3DContext(c1);
  57 var gl2 = wtu.create3DContext(c2);
  58 var gl3 = wtu.create3DContext(c2);
  59 gl1.clearColor(0,1,0,1);
  60 gl1.clear(gl1.COLOR_BUFFER_BIT);
  61 gl2.clearColor(0,1,0,1);
  62 gl2.clear(gl2.COLOR_BUFFER_BIT);
  63 gl3.clearColor(0,1,0,1);
  64 gl3.clear(gl2.COLOR_BUFFER_BIT);
  65
  66 wtu.waitForComposite(function() {
  67   // test drawArrays
  68   gl1.drawArrays(gl1.TRIANGLES, 0, 0);
  69   wtu.glErrorShouldBe(gl1, gl1.NO_ERROR, "no errors");
  70 });
  71
  72 wtu.waitForComposite(function() {
  73   // test drawElements
  74   var buf = gl2.createBuffer();
  75   gl2.bindBuffer(gl2.ELEMENT_ARRAY_BUFFER, buf);
  76   gl2.bufferData(gl2.ELEMENT_ARRAY_BUFFER, new Uint8Array(1), gl2.STATIC_DRAW);
  77   gl2.drawElements(gl2.TRIANGLES, 0, gl2.UNSIGNED_SHORT, 0);
  78   wtu.glErrorShouldBe(gl2, gl2.NO_ERROR, "no errors");
  79 });
  80
  81 wtu.waitForComposite(function() {
  82   // test draw with program.
  83   wtu.setupProgram(gl3, ["vshader", "fshader"]);
  84   gl1.drawArrays(gl3.TRIANGLES, 0, 0);
  85   wtu.glErrorShouldBe(gl3, gl2.NO_ERROR, "no errors");
  86 });
  87
  88 </script>
  89 </body>
  90 </html>