Search found 24 matches

by Calamity
16 May 2018, 15:58
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Is groovymame with 120fps BFI still a good option ?
Replies: 24
Views: 10659

Re: Is groovymame with 120fps BFI still a good option ?

Thanks for the superinformative post. Fastest QFT acceleration I have done is a VBI 3x the size of Active, transmitting a fixed 60Hz signal in a mere 1/240sec. But you can just do the 180Hz trick (for improved software BFI + hardware strobing) to get blur reduction with a hell lot less input lag, if...
by Calamity
15 May 2018, 15:39
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Is groovymame with 120fps BFI still a good option ?
Replies: 24
Views: 10659

Re: Is groovymame with 120fps BFI still a good option ?

Jimmer is an old member of BYOAC, we know each other. Well yes, the idea is that run ahead is effective for games that have internal lag. With regards to Defender, I think I tried it with beam raced GroovyMAME and I couldn't make it react any sooner than without it. Maybe the emulation still can't r...
by Calamity
15 May 2018, 13:45
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Is groovymame with 120fps BFI still a good option ?
Replies: 24
Views: 10659

Re: Is groovymame with 120fps BFI still a good option ?

My main interest is Defender which polls inputs every 8ms and writes to the 'other half' of the screen memory, that just doesn't fit into the MAME paradigm of reading the inputs once per frame. Despite Mark's passionate description, the run ahead thing won't help you with Defender. Only a frame-sli...
by Calamity
26 Apr 2018, 12:49
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Emulator Developers: Lagless VSYNC ON Algorithm
Replies: 93
Views: 46088

Re: Emulator Developers: Lagless VSYNC ON Algorithm

Alright, but the driver's frame queue can be bypassed by just polling vblank directly and presenting with vsync off, once. You don't need the added complexity of beam racing for that. ---------- With regards to frame delay, since we were the first ones to conceptualize and implement it, I feel I nee...
by Calamity
26 Apr 2018, 10:45
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Emulator Developers: Lagless VSYNC ON Algorithm
Replies: 93
Views: 46088

Re: Emulator Developers: Lagless VSYNC ON Algorithm

I'm probably missing something here. My understanding is that although beam raced run ahead is possible on the paper, the "logic" of this method would require back propagation of the mid-frame fresh input to the past frames, and then fastforwarding again to the present point, and do this for each sl...
by Calamity
26 Apr 2018, 03:25
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Emulator Developers: Lagless VSYNC ON Algorithm
Replies: 93
Views: 46088

Re: Emulator Developers: Lagless VSYNC ON Algorithm

Hi Mark, Could you clarify what do you mean exactly by "Driver's VSYNC ON delay that's beyond our control"? Is it the host video driver's lag? Or the emulated game built-in lag that the run-ahead trick tries to compensate for? Also, by "inputdelay VSYNC ON", do you mean the frame delay method? EDIT:...
by Calamity
05 Apr 2018, 12:19
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Emulator Developers: Lagless VSYNC ON Algorithm
Replies: 93
Views: 46088

Re: Emulator Developers: Lagless VSYNC ON Algorithm

But fuggedaboudit, we don't have easy access to a front buffer (yet).... You want front buffer access? Use DirectDraw :D Promise, DirectDraw allows front buffer access. Too bad the api is totally broken/emulated since 8. NVIDIA/AMD, front buffer, pretty-pretty-pretty-please? ;) This is something th...
by Calamity
05 Apr 2018, 10:45
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Emulator Developers: Lagless VSYNC ON Algorithm
Replies: 93
Views: 46088

Re: Emulator Developers: Lagless VSYNC ON Algorithm

UPDATE (for all readers), useful tip posted in WinUAE forums by mark_k. Could increase frameslice throughput. Interesting tip. I'll have to research this if this will increase frameslice throughput to achieve single-scanline-height frameslices. :D D3D9 also allows dirty rectangles with Present(), b...
by Calamity
03 Apr 2018, 10:33
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Emulator Developers: Lagless VSYNC ON Algorithm
Replies: 93
Views: 46088

Re: Emulator Developers: Lagless VSYNC ON Algorithm

Your second video (de-jittered vsync) is truly amazing. Specially considering how bad the actual vsync is based on your first video. I wouldn't have thought that was possible.
by Calamity
28 Mar 2018, 16:27
Forum: Software Developers / Low-Lag Code / Game Programming
Topic: Emulator Developers: Lagless VSYNC ON Algorithm
Replies: 93
Views: 46088

Re: Emulator Developers: Lagless VSYNC ON Algorithm

I've done some progress today. Now I can finally set an arbitrary number of slices. I can't seem to get much higher than 20 slices on my current hardware though. I'm also trying to implement an algorithm to figure out the right value of vsync offset on the fly, with little success so far.