David Haywood’s MAME(tm) WIP

Sengeki Striker has had very glitchy sprites in MAME since it was added. When I last spent time updating the Kaneko Supernova driver I made a note of a flag that was set on those sprites which apparently altered the zooming behavior, but was unable to fix it properly.

Recently a seemingly unrelated report appeared on Mametesters, which reported that the Input Test in Gals Panic S2 appeared corrupt.

A qucik check, and it was indeed setting the same flag as Sengeki Striker. This however made for an easier test case because it was more obvious how it should look.

After a couple of experiments, I figured out what the flag did, it put the sprites in a ’shrink only’ mode, allowing for better precision when shrinking, but disabling growth. Having quikcly fixed the Gals Panic S2 test mode, I fired up Sengeki Striker and found that it also looked much better with the fix, and now enemies which you shoot down correctly shrink until they hit the ground and explode rather than simply glitching all over the screen.

The screenshots below show this fix

Overall Sengeki Striker looks much better now thsn it did before. I also took a look at the precision errors causing gaps with the zooming graphics in some games using the Super Nova graphics hardware (most noticable in Jackie Chan and Gals Panic 4) but I was unable to find an acceptable solution.