Beatmap with storyboards that replace background often look wrong where there is content behind them

[bdach]

Opening mostly for tracking as a fix for this was attempted before this was even properly reported (#22035).

The case where this reproduces include:

1. Have screen scaling on, have storyboards fully dimmed. Play beatmap whose storyboard replaces background; the dimmed background that appears when scaling is on will appear behind player.
2. Go to multi spectator, have storyboards fully dimmed. Watch beatmap that has translucent storyboard that replaces background. Current game background will appear behind all players.
3. Enable beatmap backgrounds, enable screen scaling, switch to map with translucent storyboard, go to main menu.

etc. etc. For now the fix is probably to draw a black box behind everything if the storyboard replaces background (although that is pretty expensive).

Discussed in #22211

^{Originally posted by Inconsist January 15, 2023}
The video speaks for itself, is this an issue or my fault? It happend right after I left a lobby and then joined back in to spectate, my dim setting is at 100% and everything worked as intended 5 min. prior to the recording within the same session.

2.prefix00221219.mp4

2.prefix00222084.mp4

[Inconsist]

In case this adds any other info for you, I had screenscaling off during that recording, so it seems to be possible to encounter this even without it.

my settings where it happened

[bdach]

Yeah we're aware thanks. There are many distinct scenarios where this reproduces.

[Inconsist]

alright just wanted to make sure :)

[Inconsist]

https://osu.ppy.sh/beatmapsets/1544600#osu/3157178 another map where this reproduces

[cdwcgt]

I actually think the easiest way is to add a black background behind the storyboard, because storyboarders always assume the background is black

[frenzibyte]

That is not adding anything, re-read #22238 (comment), it's expensive, needs some level of profiling.