Zoom Correction Factor and Zoom Info improvements

[Bastien Dejean]

When I zoom to '1:1' what shows up in the lower right 'Z:' box is the value of the zoom correction factor.
I would expect it to show '100%' instead.

[su_v (suv-lp)]

> what shows up in the lower right 'Z:' box is the value of the zoom correction factor.

No, the box in the lower right does show the actual zoom level, relative to Inkscape's internal resolution. It has no relation to the zoom correction factor as defined in the preferences.

> I would expect it to show '100%' instead.

That's not how the zoom correction factor works (see also the tooltip of the preference setting): the zoom correction factor does not change the internal resolution - it is simply applied as correction factor to the available preset zoom commands [1]. Displaying a "corrected" zoom value in the GUI for those presets (1:1, 1:2, 2:1) would be misleading and inconsistent with other zoom levels.

Proposing to close this specific feature request as 'Won't Fix' - you probably want a different implementation of a zoom correction factor than currently offered by Inkscape.

---
[1] References:
<http://tavmjong.free.fr/INKSCAPE/MANUAL/html/View-Zoom.html>
<http://wiki.inkscape.org/wiki/index.php/Release_notes/0.47#Zoom_correction_factor>
<http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/view/head:/src/verbs.cpp#L1757>

[LucaDC (lucadc)]

All these considerations about the zoom keep happily ignoring that Inkscape's internal resolution _is_not_ an absolute unit measurement and has been _arbitrarily_ chosen between all possible ones.
The truth (that's coming out from other reports also) is that Inkscape isn't able to deal correctly with units different than its internal one (which I still can't understand for how many people is useful, while I see many people, like me, that work with _real_ units like mm).
If I'm working on a document in mm, there's no discussion on what I expect when setting a 100% zoom: if I place a ruler on my LCD screen I want (almost) correct measurements. The correction factor should take into account different monitor _pixel_dimensions_ (which are _real_ units, not supposed or imposed ones) and make the result correct for different hardwares. It's the user responsibility setting the correct correction factor but after this has been made, 100% is an absolute concept. Writing 107% (in my case) is just wrong and trying to justify it or make people believe it's correct is is even worse.
Better answer that Inkscape needs a complete refactoring in managing real units before such things can be fixed (but also others like storing correct measures in SVGs and not horrible 9-decimals numbers for page sizes that get eventually rounded somewhere and lead to 9-decimals numbers in input fields where people just wrote '2', so they complain that there are too many decimals and ask for taking them out so they can believe their numbers are stored correctly just because they don't see the error).
Sorry for complaining but this "internal-unit" argument keep sounding like an excuse to me. I understand that it's a complex issue to fix but, please, don't try to pass it as the correct approach. I'd accept it only if in Inkscape all references to real units were taken away: either you manage them correctly or you don't manage them at all (or, while you are still trying to fix problems just say the truth and tell users to wait or help for fixing).

@~suv:
>> what shows up in the lower right 'Z:' box is the value of the zoom correction factor.
>No, [...] It has no relation to the zoom correction factor as defined in the preferences.
View->Zoom->Zoom 1:1 shows the correction factor. That's what the reporter intended and what all people using Inkscape with real unit know and are used to take into account. It's not intuitive and completely misleading for new users that come from other programs where the zoom concept is correctly implemented with regard to the current unit in use.

>Displaying a "corrected" zoom value in the GUI for those presets (1:1, 1:2, 2:1) would be
>misleading and inconsistent with other zoom levels.
Of course: showing different zoom values for the presets would be completely wrong! I had to read the sentence more than twice to realize it was true as the proposal is completely absurd.
The point is that there's no need to show different values for the preset: people just expect the corrected value being always displayed and understood when input (so if I write 50% I get a 1:2 zoom).
What is misleading is the current implementation as users are not aware of Inksca...

[LucaDC (lucadc)]

Please, don't mark as "won't fix" because it would be burying the head in the sand.
And it's neither a feature request.
It's a request to fix a now misleading implementation. Being it a non obvious fix for developers doesn't change that the incorrectness of the field is obvious to users (at least to those that take their time to set the correction factor because they care about it).

[ScislaC (scislac)]

I just ran across this and yes, I completely agree that 100% /should/ show it scaled correctly on screen when you're dealing with real world units. I had actually never messed with zoom correction factor before and busted out my tape measure to set it. I was then really confused when on-canvas it wasn't the "right" size at 100%. I understand the implementation vs my intuition, but this report existing says I'm not the only person who came to that conclusion.

[Dale Walton (dale-walton)]

I just reported this as well, but it seems that now the Zoom correction factor does nothing (not even affect preset Zooms).

To me this setting should essentially be a screen display factor and thus should affect both the preset Zooms and the lower right zoom box.

I don't see why the display value of that box can't be simply divided by the preference value - my report is Bug 1482877.

[Hachmann (marenhachmann)]

I also ran into this on several occasions.

I find the intended behaviour counter-intuitive (I'd expect this setting to correct the zoom globally - I don't see a difference between 1:1 and 100%), and Dale is right, it is not applied to the preset zoom factors in 0.91, so it's currently completely without effect.

I think this could now get a different importance than 'wishlist', as even the intended way doesn't work any more.

[su_v (suv-lp)]

On 2015-08-16 16:05 (+0200), Hachmann wrote:
> I think this could now get a different importance than 'wishlist',
> as even the intended way doesn't work any more.

The regression or change in behavior in Inkscape 0.91 (the commit by Martin seems to have been intentional) is tracked in Dale's original report:
* Bug #1482877 “Changing the Zoom correction factor has no effect in the editing window”
  https://bugs.launchpad.net/inkscape/+bug/1482877

[Hachmann (marenhachmann)]

Ah okay, thanks!

[Jonathan Hofinger (jhofinger)]

Hi, this issue has also been reported to Gitlab (https://gitlab.com/inkscape/ux/-/issues/9) and we'll continue the discussion over there.

Closed by: https://gitlab.com/jhofinger