W3C home > Mailing lists > Public > www-svg@w3.org > June 2001

Re: question on spec

From: David Turner <david.turner@freetype.org>
Date: Wed, 27 Jun 2001 19:43:07 +0200
Message-ID: <3B3A1B2B.822FE0CF@freetype.org>
To: Jon Ferraiolo <jferraio@Adobe.COM>
CC: Wendell Piez <wapiez@mulberrytech.com>, www-svg@w3.org
Hello,

> 
> 1) On the outermost 'svg' element, you can define the instrinsic
> width/height of the graphic in "px" units. In this use case, a "px" is
> generally an system-dependent unit of measure. On many systems, a "px" will
> map to one device pixel, and different devices have different resolutions,
> so "px" might cause different sizes rendering on different systems. Also,
> on very high-res monitors or on printers, a "px" might be an abstract
> measurement typically in the range of 1/72 to 1/120 inch, again possibly
> causes different rendering sizes on different systems.
> 
> This case is the reason for the words: "...use of px units ... can cause
> inconsistent visual results on different viewing environments since the
> size of '1px' may map to a different number of user units on different
> systems..." But now that you bring this up, I think some additional
> rewording may be warranted.
> 
> 2) Otherwise, "A px unit and a user unit are defined to be equivalent in SVG."
> 
The following makes me wonder. Isn't it simpler to say that:

  A - a "px" is always equal to a user unit

  B - the initial/outermost viewport transform should typically
      map 1 user unit to 1 screen pixels (with variation for
      printers, etc..)

It seems to me that what's currently happening..

Comments ?

- David Turner
Received on Wednesday, 27 June 2001 13:40:23 GMT

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