Opened 21 months ago

Last modified 6 months ago

#9967 new defect

OPENGL: FM Towns Zak McKracken shows no graphics in windowed mode

Reported by: angstsmurf Owned by:
Priority: normal Component: --Other--
Keywords: Cc:


Unlike #9945 and #9946, this happens in the nighly builds using SDL 1.2.14 as well: when using OpenGL graphics windowed mode, Zak McKracken FM Towns version (the one available from GOG) will only show a black screen, though the sound is working. Fullscreen works fine.

ScummVM 1.10.0git3962-g850dcdbdf8 and MacOS Sierra 10.12.5, on a Retina MacBook
Pro, 15 inch, mid 2014.

Change History (12)

comment:1 Changed 18 months ago by angstsmurf

I just tested this again with the latest build and SDL2 2-0-6, and now the screen is black when starting in fullscreen as well. Still works fine with any non-OpenGL mode.

comment:2 Changed 17 months ago by csnover

Does this happen with any other game, or is it only the FM Towns Zak McKracken?

comment:3 Changed 17 months ago by angstsmurf

It happens in FM Towns Loom as well. I'll keep checking.

EDIT: And now it happens in full screen mode as well.

Last edited 17 months ago by angstsmurf (previous) (diff)

comment:4 Changed 17 months ago by angstsmurf

… which means that the title should be changed, I suppose.

comment:5 Changed 17 months ago by csnover

I’m not able to reproduce this issue on rMBP mid-2012, macOS 10.12.6, SDL 2.0.6, OpenGL mode, filtering on or off, using the discrete (Nvidia) GPU. Do any games render using OpenGL mode for you? Do they work if you switch between integrated/discrete GPU?

comment:6 Changed 17 months ago by angstsmurf

I only have an integrated GPU (Intel Iris Pro) in this machine. Black screen on all Lucasarts FM Towns games in OpenGL mode, and only on those. Fine in all non-OpenGL modes.

comment:7 Changed 17 months ago by csnover

Yes, but what about games that are not FM-Towns?

comment:8 Changed 17 months ago by angstsmurf

All fine.

comment:9 Changed 17 months ago by angstsmurf

Happens in official 1.9.0 build as well.

comment:10 Changed 17 months ago by csnover

OK, so I guess what is probably happening here is that the GPU doesn’t support RGB555, which is the mode used by FM Towns. I’m unfamiliar with GPU programming so I’m not sure what options exist here yet to allow this to work (other than to convert in software, which is what SDL already does when you use the normal renderer). I’ll do some research when I have time, if someone else with the prerequisite knowledge doesn’t pipe in first with an answer.

comment:11 Changed 17 months ago by angstsmurf

Thanks for looking into this! I'll just assume that I was mistaken all along about that "in windowed mode" part, it really makes no sense.

comment:12 Changed 6 months ago by digitall

Component: --Unset----Other--
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