canvas-clear-on-zero-count-draw.html (2329B)
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>