libretro / flycast

Flycast is a multiplatform Sega Dreamcast emulator. NOTE: No longer actively developed, use upstream repo for libretro from now on - https://github.com/flyinghead/flycast
http://reicast.com
GNU General Public License v2.0
152 stars 77 forks source link

Ninja Assault, Stuttering #1132

Open F0xH0L3 opened 2 years ago

F0xH0L3 commented 2 years ago

Hi. Using the latest version of the core (13/02/2022) the inputs for ninja assault seem to be fixed and p2 even works now, but it seems to have introduce a new issue... Stutter. Specifically it stutters every time you shoot or reload, easy to reproduce just by spamming the trigger or offscreen reload. Not sure if related but on the older versions of flycast, with the old input issues requiring to set the aux button as the trigger, there was zero stutter if frame rate was set to normal. On the latest version the option for framerate seems to have been removed, unfortunately, so i can't test it that fixes it. Tested on 2 setups, Win 10 With RTX3080 and I9-10900kf and Win 7 with HD7850 and I7-7700K (using for crt 15khz).

F0xH0L3 commented 2 years ago

Well, made some more tests and realized what the issue is. It happens only when the video driver is Vulkan. With GL it works just fine. Basically what's happening is with Vulkan there's no white flash when shooting as opposed to GL driver, so instead there's a hiccup when there's supposed to be a white flash frame. Edit: after using frame advance i was able to see exactly what's happening. what is supposed to happen is that after pressing the trigger, three frames afterwards there should be a white flash, with GL that is the case and that is how it's supposed to be. But with vulkan, on the third frame after pressing the trigger, instead of showing the white flash frame it instead goes back to first frame after pressing the trigger, causing the stutter/hiccup.