开发者

Blurring borders in SVG (Raphael.js)

I'm working on a web based editor wh开发者_StackOverflow中文版ere one can drag and resize elements. I've faces a problem regarding displaying 1px borders and elements: instead of pixel-to-pixel displaying (e.g. 1px solid line) I got a blurring line.

I've found that if I use coords with .5 at the end (e.g. 10.5, 124.5) and integer sizes, everything is pixel perfect.

Here is the examples. The element before I've changed its coords:

Blurring borders in SVG (Raphael.js)

And after (with ".5" at the end of each and integer size):

Blurring borders in SVG (Raphael.js)

The question is how can I force Raphael.js to display everything in sharp?


I'm not sure how to do this in Raphael, but a tiny bit of CSS could help you:

.your_lines {
     shape-rendering: crispEdges;
}

Basically it turns off antialiasing for the lines, and the lines that are not horizontal or vertical may not look very pretty.

But probably you'd better stick to adding .5 to the lines' coordinates, because browsers do what they are told to: the line is on exact coordinates and the stroke is painted on both sides of the line, half pixel here and half pixel there.


This links take you point what's going wrong with integer coordinates and why +0.5 was fixed edge blurring (with nice pictures!!):

  • http://diveintohtml5.info/canvas.html#pixel-madness
  • http://kilianvalkhof.com/2010/design/the-problem-with-svg-and-canvas/

You can avoid +0.5 by:

SVG_Area.setAttribute("viewBox", "0.5 0.5 " + width + " " + height);

or by wrapper:

function fiXY(x) { return parseInt(x) + 0.5; }

var rect = document.createElementNS(SVGobj.svgNS, "rect");
rect.setAttribute("x", fiXY(x));
rect.setAttribute("y", fiXY(y));

or by:

SVG_Area.setAttribute("shape-rendering", "crispEdges");

which effect on all shapes in you SVG image....


Based on @gavenkoa's answer, you can do this with Raphael:

var paper = Raphael('#container');
if (Raphael.svg) {
    paper.setViewBox(0.5, 0.5, paper.width, paper.height);
}

Please note the Raphael.svg check as you should not apply the 0.5px shift to IE <=8 (where VML is used).

0

上一篇:

下一篇:

精彩评论

暂无评论...
验证码 换一张
取 消

最新问答

问答排行榜