- From: Lea Verou <leaverou@gmail.com>
- Date: Wed, 15 Feb 2012 21:34:32 +0200
- To: Sylvain Galineau <sylvaing@microsoft.com>
- CC: Boris Zbarsky <bzbarsky@MIT.EDU>, "www-style@w3.org" <www-style@w3.org>
On 15/2/12 21:17, Sylvain Galineau wrote: > [Boris Zbarsky:] >> On 2/15/12 12:00 PM, Sylvain Galineau wrote: >>> OK, sorry for being slow. If the DPI causes the UA to get its inches >>> completely wrong, how does it get it right with MQs? >> CSS.1 requires that UAs ignore the real DPI to some extent and set inches >> to exactly 96 CSS px. >> > Yes, I recall that fun discussion. A CSS pixel is 1/96 of an inch. But if > the UA can't get its CSS pixels right, how can you assume dpi/dpcm works? If I recall the css3-values prose correctly, a pixel is 1/96 of a CSS inch, but a CSS inch is based on the assumption of a 96dpi resolution. So, it's the inches/cm that CSS gets wrong, not the pixels. If some devices use pixel ratios like 4 physical pixels for each CSS pixel, it's exactly because CSS never provided a mechanism to define something with physical dimensions. As a result, authors make designs that are based on pixel lengths, and thus, would be way too small on high-dpi devices such as iPhone 4.
Received on Wednesday, 15 February 2012 19:35:06 UTC