08163: dogfgt: [possible] Probable graphics corruption

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08163	Graphics	Minor	Sometimes	Dec 22, 2021, 17:25	1 day ago

Tester	brainskis	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Open	OS	Windows 10/11 (64-bit)
Status [?]	Acknowledged			Driver	technos/dogfgt.cpp
Version	0.238	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	08163: dogfgt: [possible] Probable graphics corruption
Description	I have been testing this game a fair bit and think I'm seeing graphics corruptions at different times. I created some videos to capture the bugs. I apologise in advance - I was a bit heavy handed with the Fast Forward key trying to capture all this... not noticing the glitches were being caught sometimes or just pure muscle memory. So, the videos. This one speaks for itself. These enemies come in a couple minutes into the game: Here it looks like the shrapnel graphics from the explosion are mixed up (could be by design, I guess, but seems unlikely): Next video is a bit of everything. Notice that the UFO-style enemies in this one sort of split into section sometimes - momentarily separated by the the blue background. Game seems to slow when they are hit and the glitchiness kicks in. Notice, again, the glitchy shrapnel on exploding. The main thing here for me his how jittery and spastic the other enemy planes become after the UFO starts glitching. I don't think that's meant to happen - it isn't how the game gets more difficult. Finally, I am pretty sure I have managed to glitch the screen out a few times when commandeering vehicles like in this next video. I cannot for the life of me capture the bug on video... I'm just able to capture the event when it's working. It's one to watch out for. But if anyone else ever notices this ingame maneuver going south sometimes, they ain't making it up :) On a completely different note - does anyone know what the purpose of pushing 'up' is when on foot? It looks like it triggers an evasion move but it doesn't seem to have any practical use.
Steps To Reproduce	A little inconsistent to reproduce. When the UFO enemies start appearing and shots are exchanged - the glitchy graphics tend to kick in.
Additional Information
Github Commit

Flags	Possible
Regression Version
Affected Sets / Systems	dogfgt

Attached Files

No.19590 Tafoid Administrator Dec 23, 2021, 17:36	Acknowledging pending some investigation and original PCB recordings/observations proving this is valid or not (flagged as possible for now)
No.19595 brainskis Tester Dec 23, 2021, 20:29	Agreed, Tafoid. There's a small but reasonable possibility this is just how the orignal game is, in my opinion. Lovely game, though.
No.22456 hap Developer 1 day ago	I haven't seen a full playthrough video (not MAME) that show these enemies. My observation/opinion: UFO 1 shuffling around: intentional UFO 1 shrapnel: intentional UFO 2 opening up to shoot laser: intentional UFO 2 pausing to shoot laser: probably normal jittery enemies later in game: intentional (evasive maneuvers to make it harder to shoot them?)