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Re: Making pt a non-physical unit

From: Felix Miata <mrmazda@earthlink.net>
Date: Wed, 06 Jan 2010 08:00:43 -0500
Message-ID: <4B44897B.50505@earthlink.net>
CC: www-style@w3.org
On 2010/01/06 00:05 (GMT+1300) Robert O'Callahan composed:

> Various Web sites specify font sizes for some content in pt [1]. They look
> fine in most browsers, but a length in pt that looked the same as a px
> length when DPI was 96 will be 50% longer than that px length when the DPI
> is 144. Consequently, if a browser strictly adheres to the spec and treats
> 1pt as 1/72in, these sites look bad, broken, or unusable. The problem is
> especially acute for mobile devices, because their screens are often both
> high-density and small.

> My understanding from a conversation I had on #webkit is that Webkit avoids
> the problem by treating 1pt as 4/3px regardless of the display DPI. I think
> we probably need to do this in Gecko for Web compatibility reasons, and so
> for the sake of honesty in Web specifications, I propose that the definition
> of pt in CSS be altered accordingly.

If pt/pc would be better off at some arbitrary size rather than a realistic
attempt at life size I suggest that choice be best left ultimately to users
in the form of a size based upon the desktop environment's application font
or general font or whatever the particular environment calls it. My first
choice would be 1pt = 1/12 of a root em, which would mean 12pt would still
equal 16 device px on systems where the DTE assumes 96 DPI and the user has
not changed any system defaults.

I think Webkit and IE are wrong and the spec should be left as it is.
-- 
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Felix Miata  ***  http://fm.no-ip.com/
Received on Wednesday, 6 January 2010 13:01:10 GMT

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