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

From: Andy Little (andy_at_[hidden])
Date: 2005-10-05 01:27:52

"Vladimir Prus" <ghost_at_[hidden]> wrote
> Andy Little wrote:

>> Just provide alternative unit systems. Then we can all choose the ones we
>> want, when we want.
>>
>> Hows that?   :-)
>
>    template<class CoordinateUnit>
>    class Widget {};
>
> ?
> Well, over my dead body ;-)

The cleanest way to deal with units would be as a world to device transform 
which is applied to the window at runtime as has been mentioned before. So it 
would be:

Transform  t;
Widget  w(t);

 ... code dealing with coordinates needs only use floats or ints ,

Now you can change the transform to whatever unit you wish. and your code will 
be units independent.  Of course the default could be pixels so that "old 
timers" such as yourself who may be slightly frightened of units dont ever have 
to see them. ;-)

regards
Andy Little