Barend, thanx for Your answer but I'm still surprized. Maybe I'm stupid or limited but look:
If I use Visual Basic (I know, it's awful) I've got a Screen object there. Screen object gives me an attribute TwipsPerPixel for both vertical and horizontal directions. And it is exactly what I thought. It gives me a real ratio to go from device units to real world units. And I'm pretty surre for the C (C++) there must be API to get these ratio. Of course it is applicable for MS Windows (what I'm interested in actually). But nonetheless thank you for the explanation that Adobe SVG doesn't support it. It's good to know. Another question is: why is this real world unit posibility included in the standard if it is not supported at all. I thing it is natural that if I write 100mm, I see 100mm and not anything else. By the way. If I say <svg width="100mm" height="100mm" viewBox="0 0 100 100"> <rect x="0" y="0" width="100" height="100"/> </svg> what am I suposed to get? 100 pixels wide rect? How the Adobe calculates the size in pixels of the rect? regards Maciek --- In svg-developers@yahoogroups.com, Barend Köbben <[EMAIL PROTECTED]> wrote: > I am sorry to see that you got surprised by it, but please note that it's NOT an SVG issue, it's true for any screen-drawing... > > If you state that "mm (...) must be displayed exactly so on the > screen - independent of the screen resolution or the display device", you are asking an impossible thing. > > It might calculate how many pixels theoreticaaly would go into a mm if the screen is supposed to have a 72 dpi resolution, but how is the application to know how big a pixel REALLY is on your screen...? It might be able (depending on the OS and so on) to find out to what resolution your graphics card is set and maybe even how large the screen is "supposed" to be, but as soon as somebody fiddles for example with the screen controls and changes the horizontal or vertical sync, or connects another type of monitor, the size of you rectangle would change! > > > ____________________________ > Barend Köbben > International Institute for Geo-information Sciences and Earth Observation (ITC) > PO Box 6, 7500AA Enschede (The Netherlands) > ph: +31 (0)53 4874253; fax: +31 (0)53 4874335 > _____________________________ > ----- To unsubscribe send a message to: [EMAIL PROTECTED] -or- visit http://groups.yahoo.com/group/svg-developers and click "edit my membership" ---- Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/svg-developers/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
