Bad graphics performance

[Unrud]

Games run with a low frame rate. In the host's (Ubuntu 20.04) version of DOSBox they run twice as fast.

Results from DOS Benchmark Pack:

Benchmark	Flatpak	Host
Chris's 3D Benchmark 640x480	34.4	58.3
PC Player Benchmark 640x480	18.1	42.4
Doom max. details	66.9	110.2
Quake timedemo 640x80	9.2	22.0

Both versions use the same dosbox-0.74-3.conf and the output to stderr/stdout when running is identical.

[AsciiWolf]

Hmm, this is weird. I am not sure what is causing this regression. What GPU and drivers do you use? Are there any errors/warnings on stdout of the Flatpak version?

[Unrud]

What GPU and drivers do you use?

Intel.

Are there any errors/warnings on stdout of the Flatpak version?

No. When running the benchmark they just print DOSBox switched to max cycles....

[Unrud]

Workaround: Change the setting output=surface to output=opengl.

Benchmark	Flatpak	Host
Chris's 3D Benchmark 640x480	66.7	97.0
PC Player Benchmark 640x480	42.3	58.1
Doom max. details	135.3	139.3
Quake timedemo 640x80	28.2	30.0

The numbers are much close now.

[AsciiWolf]

Hmm, that's interesting! Maybe the non-Flatpak version of DOSBox has OpenGL renderer as default? However, the numbers are still lower than the native ones. I unfortunately did not have enough time to look into this. :-/

[Unrud]

Maybe the non-Flatpak version of DOSBox has OpenGL renderer as default?

No, both use surface as default.

I tried running the host version of dosbox together with the host libraries (other than libc.so.6, libdl.so.2, libpthread.so.0 and librt.so.1) using LD_LIBRARY_PATH inside of Flatpak. It did not solve the problem.