I recently discovered an odd difference in emulation between RetroArch on my Windows 7 PC and Odroid Retro Arena (ORA) on my Odroid XU4, specifically in the games GoldenEye and the ROM hack, GoldenEye X. I used two different cores on each device, ParaLLEl and Mupen64Plus, each set to the same settings on each device (On my Windows 7 PC, I was using RetroArch 1.7.5. I have tested RetroArch 1.7.7 with Mupen64Plus Next, which seems to emulate the same as 1.7.5 with standard Mupen64Plus.). The games are running at a 640x480 resolution stretched to 16:9, with 16:9 selected in the in-game options. I took several screenshots for comparison, which is linked here; https://imgur.com/a/iLx9iiM . The main issue is fog not being displayed properly on ORA.
ParaLLEL GoldenEye: The main purpose of showing off ParaLLEl was to show the consistencies in emulation between RetroArch and ORA. In GoldenEye, both have the sky leaking in on the sides (Which happens to be blue. On different levels, the color changes depending on the sky). Both have black bars on the top and bottom (These should not be here in GoldenEye). All of these issues listed are fixed by Frame Buffer emulation, which you can see in Mupen64Plus with that setting on.
ParaLLEL GoldenEye X: In GoldenEye X, the main menu on both has an all black background. When in actual game-play, you can see there are not black bars on the top and bottom of the screen, which there should be (The reason there should be black bars in GoldenEye X and not GoldenEye, it’s because GoldenEye X is a ROM hack for Perfect Dark. Perfect Dark has these black bars on the top and bottom, while GoldenEye does not). All of these issues listed are fixed by Frame Buffer emulation, which you can see in Mupen64Plus with that setting on.
Mupen64Plus Frame Buffer Off GoldenEye: In GoldenEye, both have the sky leaking in on the sides. There are also black bars on the top and bottom. The only difference is that the fog effect is not working on ORA, but it is working on RetroArch. This issue is persistent on ORA even with Frame Buffer on.
Mupen64Plus Frame Buffer On GoldenEye: In both, the sky leaking in on the sides and the black bars have gone away. However, the fog is still not working on ORA. I originally thought it was a frame buffer issue, which is why I compared both. But clearly frame buffer has nothing to do with it.
Mupen64Plus Frame Buffer Off GoldenEye X: In GoldenEye X, the menu once again has an all black background on both. In game, the black bars on the top and bottom are missing.
Mupen64Plus Frame Buffer On GoldenEye X: In GoldenEye X, the menu now has a transparent, blurred out effect for the background in RetroArch. This is how it should be. However, in ORA, it is still a black background. That frame buffer effect is not being displayed properly. However, in game-play, both contain the black bars on the top and bottom. RetroArch can display both frame buffer effects, while ORA can only display one of them.
In conclusion, ORA is not displaying fog properly in GoldenEye. In GoldenEye X, the main menu background effect is all black and not a blurred out image. I have done further testing with Lakka on my Odroid XU4 and RetroArch on Android, which also have the same issues as ORA. I don’t know why these issues are occurring in the first place or how to fix them. Does anyone know how? Thank you.