webgl-disable-test.html (1553B)
1 <!DOCTYPE html> 2 <html class="reftest-wait"> 3 <head> 4 <meta charset="UTF-8"> 5 6 <script type="text/javascript" src="webgl-utils.js"></script> 7 <script type="text/javascript"> 8 /* Disable Test 9 * 10 * If we succeed in getting a WebGL context, we will fill 11 * the canvas with red. If we fail to acquire a WebGL context, 12 * we will use Canvas2D to instead fill it with green. 13 * 14 * Note that this test differs from the others in that 15 * it will draw differently if it receives a WebGL context. 16 * Other tests are designed to fallback silently to Canvas2D. 17 * 18 * We use this test to assure that when we disable WebGL, 19 * WebGL does not function. This is trivially true for systems 20 * that don't support WebGL. This test is not viable for testing 21 * that WebGL works, as blocklisted systems will always draw green. 22 */ 23 24 "use strict"; 25 26 function renderGL(gl) { 27 gl.clearColor(1.0, 0.0, 0.0, 1.0); 28 gl.clear(gl.COLOR_BUFFER_BIT); 29 gl.finish(); 30 } 31 32 function renderBackup(canvas) { 33 var context = canvas.getContext("2d"); 34 context.fillStyle = "rgba(0, 255, 0, 1.0)"; 35 context.fillRect(0, 0, 256, 256); 36 } 37 38 function runTest() { 39 var canvas = document.getElementById("canvas"); 40 var gl = initGL(canvas); 41 42 if (gl) 43 renderGL(gl); 44 else 45 renderBackup(canvas); 46 47 waitForComposite(testComplete); 48 } 49 50 function testComplete() { 51 document.documentElement.removeAttribute("class"); 52 } 53 </script> 54 </head> 55 56 <body onload="rAF(runTest);"> 57 <canvas id="canvas" width="256" height="256"></canvas> 58 </body> 59 60 </html>