Re: [boost] GUI coordinate units (Was: GUI foundations)

From: Martin Bonner (martin.bonner_at_[hidden])
Date: 2005-10-06 03:05:09

----Original Message----
From: Joel de Guzman [mailto:joel_at_[hidden]]
Sent: 06 October 2005 02:59
To: boost_at_[hidden]
Subject: Re: [boost] GUI coordinate units (Was: GUI foundations)

> Stefan Seefeld wrote:
>> Dave Harris wrote:
>> 
>> 
>>> Why millimeter rather than inch or point? For text, there is a
>>> strong argument for using imperial rather than metric units. A
>>> point is 1/72th of an inch, so it converts nicely. Points don't
>>> convert so well to millimeters.
> 
> A point is simply 0.35277777777777777777777777777778 millimeters :-)

So should we use boost::rational to store the positions?  Then a point is
254/720 millimetres.

Incidentally, the UK changed the legal definition of an inch to 25.4mm in (I
think) the 50's.  Does the US use the same definition, or a subtly different
one?

-- 
Martin Bonner
Martin.Bonner_at_[hidden]
Pi Technology, Milton Hall, Ely Road, Milton, Cambridge, CB4 6WZ,
ENGLAND Tel: [phone]