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Re: Making pt a non-physical unit

From: Thomas Phinney <tphinney@cal.berkeley.edu>
Date: Tue, 5 Jan 2010 12:04:53 -0800
Message-ID: <f49ae6ac1001051204i6243d5c3j84bfb13f54ca7308@mail.gmail.com>
To: fantasai <fantasai.lists@inkedblade.net>
Cc: robert@ocallahan.org, Alex Mogilevsky <alexmog@microsoft.com>, www-style <www-style@w3.org>, Melinda Grant <Melinda.Grant@gmx.com>
On Tue, Jan 5, 2010 at 11:45 AM, fantasai <fantasai.lists@inkedblade.net>wrote:

> Robert O'Callahan wrote:
>
>> On Wed, Jan 6, 2010 at 6:45 AM, Alex Mogilevsky <alexmog@microsoft.com<mailto:
>> alexmog@microsoft.com>> wrote:
>>  >  Robert O'Callahan wrote in <
>> http://lists.w3.org/Archives/Public/www-style/2010Jan/0058.html>
>>
>>  >  >   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
>>  >
>>  >  For the record, IE treats “pt” the way you propose for a number of
>>  >  versions already.
>>
>> Thanks for the info! Then we should definitely change the spec.
>>
>
> What about locking things the other way, 1px == 3/4pt? That seems
> less drastic, because at least you're keeping the 1pt = 1/72in.
>

That is indeed the definition of a point (1/72 of an inch, either
approximately or exactly, depending on where you're coming from). It's
always so exciting when word definitions need to be revised from their
historical meaning to match somebody's implementation.

Using the Windows ratio for pixels to points (4:3, vs Mac 1:1) combined with
the Mac ratio for pixels to the inch (72, vs Win 96) seems like an odd
combination, but maybe it's the most logical here.

Cheers,

T
Received on Tuesday, 5 January 2010 20:05:28 GMT

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