Bug 73316
| Summary: | Losing text sharpness (blur) when scaling div over a fixed position element (on mobile safari / webkit browser) | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | breakphreak |
| Component: | Layout and Rendering | Assignee: | Nobody <webkit-unassigned> |
| Status: | UNCONFIRMED | ||
| Severity: | Normal | CC: | cofturkiye |
| Priority: | P2 | ||
| Version: | 528+ (Nightly build) | ||
| Hardware: | Other | ||
| OS: | Other | ||
| URL: | http://stackoverflow.com/questions/8298696/losing-text-sharpness-blur-when-scaling-div-over-a-fixed-position-element-on | ||
breakphreak
The repro code is attached. It (basically) contains two div elements: red (fixed) and black (with text). When clicking on the black div, it is up-scaled and the text on it stays sharp. However, in 4 seconds the z-index of the black div changes and the black div becomes to be over the red div. Boom! Here the text becomes blurry (which is a big problem).
The "effect" is especially visible on iPhone 3GS, less noticeable on iPhone 4 / iPad.
The question is: is there a solution/workaround to tweak every code, but not the red div code, so that the text on the black div will remain sharp?
I am here for any questions / clarification requests.
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html><head><meta http-equiv="Content-Type" content="text/html; charset=windows-1255">
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js" type="text/javascript"></script>
<script>
$(function() {
$("#main_div").bind("click", function() {
$("#wrapper").css({"z-index": -1});
$("#main_div").css({"-webkit-transform": "scale(1.4)"});
setTimeout(function() {
$("#wrapper").css({"z-index": 2});
}, 4000);
return true;
});
});
</script>
<title>Title</title>
</head>
<body>
<div id="wrapper" style="position: absolute; z-index: 2; visibility: visible; height: 598px; top: 150px; width: 972px; left: 20px;">
<div style="position: absolute; width: 972px; height: 598px; ">
<div id="main_div" style="position: relative; height: 375px; width: 610px; background-color:rgb(2,2,2); -webkit-transform-origin-x: 0px; -webkit-transform-origin-y: 0px;">
<div style="position: relative; padding-top: 26px; padding-right: 10px; padding-bottom: 26px; padding-left: 10px; font-size: 10px; ">
<div style="display: inline; font: normal normal normal 14px/normal arial; color: rgb(150, 150, 150); ">
<span>Here is some TEXT</span>
</div>
</div>
</div>
</div>
</div>
<div style="position: fixed; visibility: visible; height: 598px; top: 150px; width: 972px; left: 20px;">
<div style="position:fixed; bottom:0; right:0; width:70%; height:30%; background-color: red;"></div>
</div>
</body></html>
| Attachments | ||
|---|---|---|
| Add attachment proposed patch, testcase, etc. |
cofturkiye
I have a bug like this, ocurs when I use preserve-3d & 3d transforms, that element become blurry. Not only fonts become blurry but also borders, background, shadows, etc. Firefox, Chrome has this problem too.
If I use -webkit-filter:blur(0px); rendered element become pixelated and loses it's blur, but it's never become sharp.
These problems are like my problem:
https://stackoverflow.com/questions/10417890/css3-animations-with-transform-causes-blurred-elements-on-webkit
https://stackoverflow.com/questions/4641522/how-to-force-re-render-after-a-webkit-3d-transform-in-safari/4847445#4847445