[MU4 Issue] Instruments are drawn outside the score if added a lot of instruments

[vshalkevich]

Describe the bug
Instruments go outside the score if added a lot of instruments on the Score Wizard

To Reproduce
Steps to reproduce the behavior:

1. Start creating a new score
2. Add a lot of instruments (about 10-15)
3. Click Done and observe created score view.

Expected behavior
Instruments should not be drawn outside the score if a lot of instruments added to the Score Wizard

Screenshots

Desktop (please complete the following information):
Windows 10

Additional context
Add any other context about the problem here.

[wizofaus]

Just for reference MU3 does the same except that it doesn't draw the staves onto the background (they're just not shown at all).
Wondering if it wouldn't be better to automatically adjust the scaling in the Page Settings to ensure all the staves always fit? But it shouldn't be too hard to prevent drawing onto the background at least.

[wizofaus]

Tried fixing this using QPainter setClipRegion (or setClipRect) while painting each page but no joy, not sure why it's not working. But MU3 does it by painting the background last using a clip region that's the full canvas area with the area needed for each page removed. To do that in MU4 would really require moving the background paint to the end of Notation::paint (it's currently in NotationPaintView::paint).
But would definitely be nicer if setClipRegion just worked as expected while painting each page.

[DmitryArefiev]

Happens again. Was broken in 4.1

bandicam.2024-03-29.14-15-04-248.mp4

[wizofaus]

If I can get my dev environment working I'm happy to refix this

[Jojo-Schmitz]

Seems from your old fix this here got lost: https://github.com/musescore/MuseScore/pull/8589/files#diff-b01b000c5ec45fd216a7232e61fffb6d5b2bdeefad8cbe917df441812dfae030, the entire file src/notation/internal/notation.cpp

[wizofaus]

The code's all still there, just that it's been moved to paint.cpp now. Looking into it.

[wizofaus]

@vshalkevich Can you confirm what you believe the expected behaviour is here - that the score should resize itself so the instruments fit? Or that the system is cropped to fit on the page, even though staves will be subsequently invisible?

[DmitryArefiev]

@wizofaus For this particular bug the expected result is the instruments outside score page should not be drawn (rendered)

[DmitryArefiev]

How it was in 4.0.0-4.0.2

[cbjeukendrup]

@DmitryArefiev But as discussed at the bottom of #22135, we realised that that is actually not desirable (see also the discussion on Slack)

[wizofaus]

V3.6 was the same as V4.0 FWIW.
The current fix is to only crop in publish mode.
In regular score view items that extend off the right of a page and on to the subsequent page are effectively cropped (because the background for that subsequent page is drawn later), but nothing else is. It's not what I would personally prefer but I can see the argument for it.