Waku Waku 7 flickering shadows

[Alturis]

Has anyone found a way to fix the shadows in Waku Waku 7? That cant be how the original arcade game was.

[lostless]

@alturis the shadows flicker at 60hz. They are there for one frame and gone on the next. It was that way in the arcade. On a crt, it would look more kinda transparent. The video you showed is only 30fps and is dropping every other frame, Making the shadows either all on or off. The pi3 has plenty of power to run at 60fps, so it won’t look like the video you showed.

[pjft]

Well, a bit more context: make sure your screen refresh rate is indeed set to 60Hz. In my case, since I'm in a PAL region, it somehow preferred to go for the 50Hz equivalent which obviously made things terrible.

When set to 60Hz, for the most part it now runs as intended - sometimes it drops a frame or something (59fps or so) but for the most part runs as intended.

[Alturis]

Hmmm... OK well then it sounds like people are seeing this issue not present which means I will have to fill in some more info.

I am using lr-fbalpha to emulate it
Running with crt-pi-curvature shader
Used runcommand to confirm that video mode is running at 60hz with 74mhz clock interlaced (CEA-5)

Seeing very flickery shadows still. Not so much flickery as much randomly on/off at different intervals.

Going to try a couple things including using mame2003 instead and disabling the shader.

[Alturis]

Disabling the crt-pi shader fixes it so it looks like what I imagine it is supposed to.

Also tried using zfast_crt_curve instead which seems to help a bit but still not solve it.

So looks like this game needs to run at full speed or the ugliness will ensue.

Other thoughts on how I might retain my crt-curve shader effect and keep it at 60hz?

[Alturis]

I played around with the various video options I found in retroarch.cfg and it seems like the best result I could achieve was simply turning on video_vsync and leaving the rest to their defaults:

video_vsync = true
#video_hard_sync = true
#video_max_swapchain_images = 1
#video_threaded = "false"
#video_frame_delay = 5
#video_swap_interval = 1
video_smooth = "false"
video_shader_enable = "true"
video_shader = "~/.config/retroarch/shaders/zfast_crt_curve.glslp"

It still flickers a bit more inconsistently than if running without the shader, but it is closer to the look without as much of the odd randomness feeling.

[pjft]

It's indeed related to the FPS it's capable of rendering at. If you're using a curved shader, that will affect that somewhat - I use the plain crt-pi shader (non-curved) and as I mentioned it works well-ish for the most part, only dropping the odd frame.

I'm not fully sure but I was under the impression that vsync doesn't work on the Pi.

I may be completely wrong here, but just raising that in case that option actually does nothing other than being a placebo in this specific case :)

If you want to troubleshoot that better, set the FPS to be visible in the video menu and see how they perform. The latter Samurai Showdowns are great examples of the flickering shadows thing as well - they even used some sort of transparency for the power bars which causes some offputting visuals when it's not really at 60fps.

[Alturis]

@pjft I am also wondering if I am still somehow not benefiting from overclocking like I think I am. I enabled the fba cpu neogeo overlocking at 200% and am running with my /boot/config.txt with the arm at 1400 and gpu at 500. But since doing that I cannot say that I have noticed any change at all in the performance of any game that runs slightly slow.

[dankcushions]

@alturis these shaders dance around the limit of the pi already. even the non curved version of crt-pi would slow down for me on certain nes emulator/game combinations. i believe the bottleneck for shaders is often the system bus, and i don’t think overclocking makes a meaningful difference there. maybe ram overclock would help a little bit?

[Alturis]

Well, I tested it out with RetroArch framerate being displayed and it runs at a solid 59.9 to 60.0 fps. This is also after I updated my /boot/config.txt to use sdram_freq=500

Still doesn't quite look as good as when shaders are disabled but I am thinking this is about as good as its going to get.

Edit: I also sacrificed the curvature and tweaked my overlay bezel art to push it as fast as it could go with at least the zfast_standard shader for both Waku Waku 7 and Samurai Shodown 4 (the only games I have installed that demonstrate this issue to my knowledge)