Need help for shader comparison... RA vs. MAME

RetroArch Additions Shaders
#1

Hello Folks,

like the topic says, i need help for a shader comparison of RA vs. MAME. I encountered some issues, if i use some special cases games, like “Poitto”. This game has a unusual resolution of 360x224 pixels and if you make a screenshot of a unfiltered (no shaders applied) and original size scaled output in MAME, you will get this:

So far, so good. Now, if i want to do the same with RA, i will get this:

AFAIK, Mame dumps screenshots as the raw pixels before any aspect correction and it looks like RA does aspect correction before dumping a screenshot. Correct me, if i am wrong here. The only way to have the same result/screenshot like MAME, was to enable the “alternate rendering” method inside the MAME core options of RA:

This “alternate rendering” method, will sadly produce very different shader results :frowning: . Its important for me (and for my comparison) to know how RA handles such cases, i.e. what goes into a shader and what comes out. I need to be sure that MAME and RA handles the input of a shader in the same way and thats why i need your help here.

thx in advance

#2

The latest MAME core has some issues with rendering. If you’re wanting a pixel-perfect image to compare, you’re better off using the mame2014 core, which doesn’t have these issues.

#3

Thank you so much Hunter K., indeed worked like a charm. Your help is always welcome. I guess it has to do with the new invented integer scaling in MAME 0174. It will be fixed soon ( hopefully )… :slight_smile:

#4

My pleasure.

Hmm, that could be related, yeah. We don’t actually have any clue as to what caused it, just that it crept in when they switched their build system around. We took a snapshot (i.e., mame2014) and then rebased and it’s been like that ever since :confused:

#5

I was thinking it was something that changed in 0.172 with unevenstretch, since setting it to 0 at least helps with missing pixels.

#6

Yeah, it all has to do with the changes that are coming from Calamity (GroovyMAME author) who joined the MAME dev team. He wants to merge GroovyMAME into official MAME and can do this only in steps. Unevenstretch and integer scaling, was the first step. I know that some fixes for the integer scaling (unevenstretch included) will be included in 0179. These functions are crucial for proper CRT presentation, which is the main thing of GroovyMAME.

#7

Ah, that’s great that GroovyMAME is merging into mainline.

#8

that is great to hear