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Re: [css3-values] New WD for Values & Units

From: Laurens Holst <lholst@students.cs.uu.nl>
Date: Sat, 30 Jul 2005 20:29:42 +0200
Message-ID: <42EBC716.2030106@students.cs.uu.nl>
To: Christoph Päper <christoph.paeper@tu-clausthal.de>
CC: www-style@w3.org

Christoph Päper schreef:

> Actually I think it would have been a valid option to make 'px' the 
> device's pixel, like many people assume anyway, and instead allow 
> angular units for relative lengths, representing the visual angle of 
> the user. For example:

I disagree. To give an example to illustrate, on e.g. an MSX computer, 
there are screenmodes which have pixels which are not angular at all. 
Among the possible screen resolutions are 512 x 212 and 256 x 424 (on a 
regular 4:3 TV). These will result in non-square pixels (they are twice 
as high as they are wide and vice versa). Treating ‘px’ units as device 
pixels for those is unacceptable, it would distort the image 
unacceptably too much, they need to be compensated for instead by saying 
that e.g. 1px is 2 device pixels horizontally, or half a device pixel 
vertically, etc.

Also, pixels aren’t device pixels anyway - when the dots per inch are 
too high, their size is a multiple of device pixels.

Additionally, consider a regular 768 x 576 resolution on a widescreen 
TV. Instead of just stretching everything, I think it may be more 
desirable to compensate for the different aspect ratio. However, a safe 
margin is desirable, so that pixels are still pixels no matter whether 
they are used on a VGA, NTSC or PAL display (while they are only truly 
square on - most - VGA displays).

Received on Saturday, 30 July 2005 18:29:48 UTC

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