I can only guess here... but i highly bet, that the bloom of Lotte in RA is not well optimized or the shader in general. Bloom in a single pass, needs much power from GPU. This is a thing, that also needs to be optimized for the MAME versions. I really cant tell, because my RA is from Okt. 2014 and there is no Lotte shader
I dont believe, that we will have the CRT-Royale shader anytime soon. It is one of the most complex shader available and consists of 12 shaders in one package. There are no source files of it and you cant just take a RA shader and convert it, because its allready in a optimized language, that has not much in common with GLSL, even if the source was once GLSL.
I am happy that Hunter K. (RA Admin) even helped me, to convert the CRT-geom shader, because there is no really good friendship between RA and the MAME devs. CRT-Royale is one exclusive thing to RA and to ask for help in a conversion for it, would wear out one´s welcome
I dont want that, i want more friendly relationships
and Hunter K. is a nice dude. A conversion may sound easy, but it is not. GLSL for MAME has no real documentation and there is no debugging tool for GLSL in general. So most of the time, its hard trial and error.... and frustration
My own priority, is first to have a optimized and complete CRT-geom shader, that is like the current one we have, but with bloom and the interlace fix. Once this is done, i have more plans i dont want to talk about yet. Also there are more upcoming things for HLSL from the hardworking Jezze, who made HLSL so much better since v0161 and that keeps me busy too.
All in all, there where huge improvements in the first half of 2015, regarding shaders and MAME and there are not many people that are aware of this fact. A state that needs to be changed. It is worthless to put so much effort in a thing, that people not even know and you can do a way more things, that you could not do in the past.