Alien Swarm SDK - Hammer (640)

Compatibility Report

• Name of the game with compatibility issues: Alien Swarm - SDK
• Steam AppID of the game: 640

System Information

• GPU: RTX 2070
• Driver/LLVM version: nvidia 495.44
• Kernel version: 5.10.79-1-MANJARO
• Full system information report: Gist:
• Proton version: 6.3-8 (also tried experimental, same issue)

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

Log:

steam-640.log

Symptoms

When using hammer, it's unusually slow and stuttery, for the performance tier my machine is at.
In addition to that, the viewports tend to flicker black, and hide/show their text at random times, but especially the textured 3D view when selecting an object. the entire window can also go black, and buttons reveal themselves when hovering

Reproduction

1. Launch the Alien Swarm SDK
2. Launch hammer
3. Create or open a map
4. Try to edit it, if time won't trigger it, trying to switch the brush texture will

Extra notes

• Loading with OBS open, and nvidia's framebuffer capture enabled via a driver patch, and hooked into it, seems to mitigate the problem sometimes, to where the window won't go black from time (still from opening brushes), and it's faster (not as fast as windows though) but still flickers
• On my laptop (I5-5300U, Intel HD 5500, mesa drivers) the flickering and black window issues are there, however it runs much faster, again not as fast as native though

Demonstration Video

https://user-images.githubusercontent.com/16214950/144529061-cd8261cc-bafa-4077-9704-fba90abdfb82.mp4

Start by reproducing the issue with Alien Swarm SDK Hammer using the listed steps, then inspect steam-640.log alongside the demonstration video and system information. Done would mean identifying and resolving the slow rendering, black viewport/window flickering, and hidden controls under the reported Proton environment.