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Re: Making pt a non-physical unit

From: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Date: Fri, 15 Jan 2010 19:08:55 +0100
Message-ID: <cb7bb73a1001151008s4669889br6383d28bcd1fbc22@mail.gmail.com>
To: Brad Kemper <brad.kemper@gmail.com>
Cc: "Tab Atkins Jr." <jackalmage@gmail.com>, "robert@ocallahan.org" <robert@ocallahan.org>, www-style <www-style@w3.org>
On Fri, Jan 15, 2010 at 6:29 PM, Brad Kemper <brad.kemper@gmail.com> wrote:
> I understand the reasoning of the current definition of px, and after thinking about it I think it may help to simply deal with those "2 device pixels = 1px" situations as **zoom**. Thus, "(1px:1 pixel ratio) = zoom:1" and "(1px : 2 pixel ratio) = zoom:2". Then when we provide that guidance about "0.0213 degrees" pixel sizes, we can say that whenever one device pixel would be bigger or smaller than 1px (after rounding to nearest integer), then a 'zoom' should be used to indicate this difference, and the user should have clear controls for changing the zoom level. Then, if the author really wants the one to one relationship for their page, they can set something like this:
> body { zoom:1; }
> That authored zoom level should then be reflected in any UA menu that showed the zoom level, and the user could override it if they want.

That's more or less what my CSS-to-real units ratio directive aimed at
obtaining, but rather than present it as 'zoom', by expressing the
actual intended relationship. When the designer expects 1px to match 1
device pixel, he'd write body { reference-length: 1px = 1px }; if the
designer expects 1in to match 1 physical inch, he'd write body {
reference-length: 1in = 1in} (or whatever other syntax is chosen).
This way, rather than talking about zoom levels (which is still rather
abstract, since no inference about the physical dimensions is
considered) the accent is put about physical-to-CSS units ratio, which
is what is actually intended (no?)

Giuseppe "Oblomov" Bilotta
Received on Friday, 15 January 2010 18:09:48 UTC

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