Slam! - Graphical glitches when puck/players are in fast movement

[mskrzynski]

Slam! works fine but the graphics seem to be glitching where parts of the puck and players go missing while in fast movement. You can see it in the video I've recorded here: https://streamable.com/ebtzrx

It should be solid all the time.
I am using latest version - otvdm-master-2246.

[cracyc]

I don't see this, it might be a video driver/dwm issue. What display adapter do you have?

[mskrzynski]

Compare this to how it looks on other videos like here:
https://youtu.be/RIgQrWYQX_E?t=14
https://youtu.be/CHp6SGm0-Os?t=149

I have AMD Radeon R7 265, but I've noticed the same thing using GeForce drivers with RTX 2060/GTX 660.

The game can be downloaded here for reference: https://www.classicdosgames.com/game/Slam!.html

[cracyc]

Since I can't repo it I really can't debug it. The program uses GDI primitive calls for everything so it's highly likely the problem is in the GDI or below not in winevdm. I believe that the GDI is single buffered so the problem could be with the display driver or dwm not syncing to vblank and thus causing tearing.

[ArguaBILL]

I have a completely different issue with this game, and that is that the samples you can hear in mskrzynski's provided video aren't playing (and yes I do have the sound option enabled)

[otya128]

Tearing is also occurring in that video


.

[mskrzynski]

It is not as severe, and it looks different than in my video. Here it is cut horizontally, but in my video parts are missing like a square being cut off. I have played this game before on Windows 98/XP and do not recall such an issue, hence my report. Will recheck on other OS and with DWM enabled/disabled and do more throughout testing.

[ArguaBILL]

The ultimate test would be to build a genuine Windows 3.11 machine with a decent video card (one of those "Windows accelerators" or something.)

Also, I have reason to believe that the screen tearing could be caused by that guy's VGA capture device as there's some light tearing in his WinTrek video too

[mskrzynski]

Using the latest version at the time of writing this (otvdm-master-2411) and with changes to the hardware since the issue was created (Radeon RX 6600, Acer K243Y monitor at 75Hz with Freesync, updating to Windows 11) I tested it again and the issue seems to be resolved, both the blue players and the purple puck are rendered fully in fast motion (not in chunks like in the video) as intended.
The sound effects are working correctly as they always were.