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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

Martin Bonner
Pi Technology, Milton Hall, Ely Road, Milton, Cambridge, CB4 6WZ,
ENGLAND Tel: +44 (0)1223 441434

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