Other monitor turns off, terrain turns black

[Silken Healer]

Lix version: 0.10.31 64-bit (not the compile yourself version)
Operating System version: Windows 10 LTSC 2021 64-bit English-United Kingdom, Version 21H2 OS Build 19044.5854
Description: Recently, I was playing a two-player multi-player Lix netplay session with Simon from IRC. Whilst I was playing, I noticed one of my other monitors had a "this monitor hasn't had any activity, powering off soon, press OK to cancel"-type messages. The way I was sitting, it's a bit delicate to get up and get the TV remote to turn it off, so I decided to just let it power off, as I wasn't using it. After doing so, the terrain on Lix turned black. Also, I had two Lix windows open, I also had a second, windowed "neutrals" Lix instance, which this also applies too. I've also attached the replay to the post. After loading the next round, everything was fine agian.
Steps to reproduce:
I haven't tested if it's reproducible yet, but I suppose you should just

• Have a multi-monitor configuration
• Open Lix and load a level
• Turn one of your other monitors off
• The terrain should change black

Screenshots/Recordings:
Luckily, I like to record my Lix sessions from IRC with Simon to look back one, so I was recording this all, I will add a recording later once I figure out how to use FFMPEG to trim a recording based on two timestamps without re-encoding it, but for now, here is a screenshot.

[Simon]

Thanks for the report!

Lix is on monitor A, monitor B turns off, terrain in Lix (still on monitor A) becomes black. Yeah, I should investigate together with those other monitor bugs that you filed in 2025.

-- Simon

[Silken Healer]

Ah so terrain was what differentiated what turned black and didn't, I'll change the title and post to reflect that.

[Simon]

These monitor bugs -- wonder why nobody has run into them before, and you found 3 or 4 of them already this year. And you're not even using Windows 11, which is nowadays's easy blame target.

This one is particularly astounding. The already-loaded sprites, exits, hatches, ... all remain intact. Only the terrain layer becomes black or transparent, even though it's a VRAM bitmap like any other sprite/exit/hatch. Or is it? I should research. But then new terrain (the later-built staircases) can be painted onto the black/transparent as if nothing were out of the ordinary.

The terrain VRAM bitmap may be large (it's a single piece, 1:1 the size of the level), but the spritesheet is also large at 913 x 946, about the same order of magnitude as that map. That would rule out size.

No idea, must reproduce from first principles. And first find a multi-monitor setup.

-- Simon

[Silken Healer]

I think you can simulate a multi-monitor setup in virtual machines if you don't personally use a multi-monitor setup already and it would cost more time/money then is worth to get one to test this bug e.g. if you don't just have a spare TV you can plug in to your computer or something.