Rotate and perspective sliders swapping places between horizontal and vertical images

[Hpbirkeland]

Describe the bug

In the rotate and perspective module, the sliders for lens shift (vertical) an lens shift (horizontal) swap places depending on the orientation of the image. First of all it is confusing to not always find the same slider in the same place. Also, assigning dynamic shortcuts to those sliders does not make sense. If I assign a shortcut to "lens shift (vertical)" on a landscape oriented image, this shortcut will adjust "lens shift (horizontal)" on a portrait oriented image.

Steps to reproduce

1. Open a landscape oriented image
2. Open the rotate and perspective module
3. See that Lens shift (vertical) is listed first, thne Lens shift (horizontal)
4. Open a portrait oriented image
5. Watch the two sliders swap places

Expected behavior

The horizontal and vertical sliders should always stay in the same place and have the same practical effect regardless of image orientation.

Logfile | Screenshot | Screencast

No response

Commit

No response

Where did you obtain darktable from?

OBS

darktable version

5.0.0

What OS are you using?

Linux

What is the version of your OS?

Mint 22 Cinnamon

Describe your system?

No response

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

Nvidia RTX 4060 Max-Q/Mobile,

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

[ralfbrown]

That's because the orientation module runs after rotate and perspective (notice how orientation is above r&p in the active modules tab). So r&p is always operating on a landscape-orientation image unless you have one of the rare early cameras which actually rotated the image data instead of merely putting a metadata tag in the file.

If it's an issue for you, you can drag one of the modules past the other to reorder them in the pixelpipe.

[dterrahe]

There are two ways the mismatch between the shortcut name and the current slider label could be resolved:

• the introspection descriptions of the two sliders (which are used to name the shortcuts) could be renamed to something more abstract, like lens shift (top/bottom), lens shift (first/second) or lens shift (short/long side) This would be done here
  

  darktable/src/iop/ashift.c

  Lines 280 to 281 in e4b105e

  	float lensshift_v; // $MIN: -LENSSHIFT_RANGE_SOFT $MAX: LENSSHIFT_RANGE_SOFT $DEFAULT: 0.0 $DESCRIPTION: "lens shift (vertical)"
  	float lensshift_h; // $MIN: -LENSSHIFT_RANGE_SOFT $MAX: LENSSHIFT_RANGE_SOFT $DEFAULT: 0.0 $DESCRIPTION: "lens shift (horizontal)"

  
  The gui of the module would still show horizontal/vertical based on current orientation and the same shortcut would still impact varying sides.
• the sliders could be reconnected to different internal variables, instead of relabeling them, using dt_bauhaus_widget_set_field (and updating the sliders from the current values of the lensshift_v/lensshift_h fields).

[Hpbirkeland]

I understand that I could place the module after orientation, but then I would have to navigate to the module anyway, and then I could just use the sliders directly and there is no point in having shortcuts. This is also about consistency. As long as shortcuts are possible for sliders, they should be equally possible for all sliders. And I still don't quite understand why r&p could not just be after orientation in the first place.

[ralfbrown]

You can make an auto-apply preset in the "module order" module.

[Hpbirkeland]

I tried that, but didn't get it to autoapply. Maybe I should try again. And Happy New Year to all of you🎉

[github-actions]

This issue has been marked as stale due to inactivity for the last 60 days. It will be automatically closed in 300 days if no update occurs. Please check if the master branch has fixed it and report again or close the issue.