<!DOCTYPE HTML> <html> <!-- https://bugzilla.mozilla.org/show_bug.cgi?id=389366 --> <head> <title>Test for Bug 389366</title> <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script> <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" /> </head> <body> <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=389366">Mozilla Bug 389366</a> <p id="display"></p> <div id="content" style="display: none"> <h4>Canvas testcase</h4> Canvas, with pixel set to #ff0000 at 50% opacity:<br> <canvas id="canvas1" width="10" height="10"></canvas> <br> <canvas id="canvas2" width="10" height="10"></canvas> </div> <pre id="test"> <script class="testbody" type="text/javascript"> SimpleTest.waitForExplicitFinish(); function test() { // Draw to canvas1 var canvas1 = document.getElementById("canvas1"); var ctx1 = canvas1.getContext("2d"); ctx1.globalAlpha = 0.502; ctx1.fillStyle = "#FF0000"; ctx1.fillRect(0, 0, 10, 10); var data1 = ctx1.getImageData(0,0,1,1).data; isDeeply(data1, [255, 0, 0, 128], "expected half-transparent red canvas 1"); // half-transparent red 10x10 square var imgData = ctx1.createImageData(10, 10); var rgba = [ 255, 0, 0, 128 ]; for (i = 0; i < 50; ++i) { for (j = 0; j < 4; ++j) { imgData.data[(i * 4) + j] = rgba[j]; } } var canvas2 = document.getElementById("canvas2"); var ctx2 = canvas2.getContext("2d"); ctx2.putImageData(imgData, 0, 0); var data2 = ctx2.getImageData(0,0,1,1).data; isDeeply(data2, [255, 0, 0, 128], "expected half-transparent red canvas 2"); SimpleTest.finish(); } addLoadEvent(test); </script> </pre> </body> </html>