Greetings guys. I’m just looking up for any suggestions that you could ever help me with to use video filters on DOS games.
I would appreciate any suggestion you could ever bring.
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Filters and shaders are actually two different things in Retroarch. The filters wouldn’t be very useful I suppose if you’re trying to keep it semi-realistic for anything DOS though. DOS game can mean anything from monochrome, composite (usually CGA, unless you want try to mimic some kind of TV-out of later cards), and clear RGB of varying resolution. So you can have potentially a lot of variations.
I mean shader presets, most likely. Any suggestion is welcome and appreciated.
Duimon’s pack has a whole folder full of DOS presets. I use the adv-guest-monitor version, but I’m sure you could find one in there you like.
The original IBM VGA card employed a technique called line-doubling which rendered a 240p image on a 480p monitor. That said, not all VGA-compatible cards did this. When line-doubling is used, you wouldn’t see scanlines on a standard VGA monitor.
Computer monitors used shadow masks which gave a rather soft image, exasperated by the line doubling. I’m not sure if there were any Trinitron monitors for PCs in the early 90s, though Apple’s were Trinitron.
You also want to avoid too much geometric distortion (or none at all), because computer monitors employed techniques to ensure the entire picture was visible and legible. If you were alive to remember CRT computer monitors you may recall how they had a black border around the screen with stock settings. This was to ensure that the edges were not too distorted.
All this goes out the window for CGA games, particularly in composite mode, because those games relied on the user supplying their own television as a monitor. But 99% of the time people are playing VGA+ games on DOS.
You can find a lot of good discussion about all this on Vogons. My own shader can be configured to give a good VGA display, but my presets aren’t ready yet. The manual has some recommendations for how to set parameters for VGA.