Dither blending filter

[Nashismo]

Hi dear ekeeke:

I have seen something truly wonderfull on this Mega SG console where it has an option to do dither blending. Which is in summary to make real transparacy happening!

This work in games like Sonic (waterfalls), Shinobi (water) or Streets of Rage. But essentially in all games that use grid pattern like effects.

I know that using the option "composite" on GenPlusGX delivers this effect, but the image ends up looking horribly blurry, which of course is to be expected.

The point of this "Dither blending" option is that it works without making the whole image a blurry mess, only blending what needs to be blended.

Thank you so much for your time ekeeke, I will still be glad to hear what you think of this, or if it could be possible somehow!

My best regards,
Nashismo

[ekeeke]

There are quite a few CRT shaders in Retroarch that do this so you might want to try them out.

That said, it should be possible to do it using a software filter (I think the TV filter in Kega Fusion does something similar). It would indeed improve the rendering of some pixels patterns used in many games to fake transparencies or extra colors (although as I grew up with a French RGB Megadrive, I never saw those effects on original console).

The difficulty (also faced in existing shaders I think) is to properly detect the patterns that need to be color-mixed and avoid fake detections. It also does not help that Mega SG FPGA or Kega Fusion implementations are closed source.

[Nashismo]

Thank you for seeing this and for taking the time to answer back ekeeke!

I understand then that Mega SG and Kega Fusion are closed source mmm, how sad. But the problem is that the other option, which is to use Retroarch, won't work, as Retroarch Wii cannot use these shaders you mention! :( (probably the Wii is to weak for that, or simply hasn't been implemented).

Well, in case you ever want to try this out, I would be willing to test it out if you want me to. I have a Sony Wega CRT, and I have 2 different cables to connect my Wii, S-Video and Component.

Cheers and my best regards, I am always thankfull to you for this wonderful emu and port.

Nashismo.