Update January 2019: MAME 206 corrects the HLSL shader, so the purple screen is gone.
The 'Scale' values as described below are now in lines 186 and 191. Now I need to head for the new phosphor settings and update the below table for HLSL settings (I still do not like the default settings that much). Below you find the updated table of my current HLSL settings plus the Scale values for the lines 186 and 191.
Update December 2018: Since the October 2018 release, the HLSL shader has been updated by phosphor settings. As a result, BGFX/HLSL produces a purple picture, at least on my Mac in both MacOS and Linux - is this an SDL MAME problem? I am still investigating into that, and for the time being, I stay with BGFX/CRT-GEOM-Deluxe, which still provides very decent results.
|HLSL under Windows (Bootcamp)|
|HLSL under MacOS and Ubuntu|