Someone is working on a multi-core, OpenGL ES Saturn emulator

[dankcushions]

…and it’s playable on android!

it looks like the main breakthroughs have come from using Open GL ES 3.0 (pi only has 2.0, but still), and asynchronously using cores (pi 2 has 4!), so that sounds good!

I’ve done some digging, and it looks like the source isn’t available, but at least it shows that there’s a glimmer of hope for saturn emulation on the pi :)

[dankcushions]

looks like the source is available:
https://github.com/devmiyax/yabause

this appears to be a fork from standard yabause:
https://github.com/Yabause/yabause

and the libretro version (on retropie) appears to be a fork from the standard:
https://github.com/libretro/yabause

it seems like the libretro version had a merge from the standard version a while back, and the standard version is getting the new stuff merged in when it’s stable (from the comments in https://github.com/Yabause/yabause/issues/17)

not sure if it’s worth me opening an issue in the libretro version to request a merge when it’s all still in flux – don’t want to step on anyone’s toes! :)

[machtroid]

That’s good news! That means we can bring Panzer Dragoon Saga and Radiant Silvergun to the Pi! I haven’t tried the experimental Yabause up to now because I heard it wasn’t in a very good state, but this seems like the improvement needed to get Saturn emulation moving in the right direction.

[Anonymous]

Ooooo!!!!! I hope it works well!

[dankcushions]

small update on this:

bad news: the android open gl es version of yabause is using opengl es 3.0. the raspberry pi’s videocore IV GPU has only opengl es 2.0 support. i asked devmiyax (the guy coding it) if it would be possible to port it to opengl es 2.0, and the answer is no (https://github.com/devmiyax/yabause/issues/36) – it seems it needs a specific es 3.0 command that is proving difficult (impossible?) to replicate in es 2.0 – gl_FragDepth.

good news: eric anholt and others have been working on an open graphics driver for the raspberry pi – http://dri.freedesktop.org/wiki/VC4/ – i have hope that this new driver will allow for the possibility of gl extensions that can paper over these gaps in the existing open gl spec. eg: GL_EXT_frag_depth, or maybe even a full ES 3.0 implementation. i believe this driver is already open gl 2.0 (NOT ES) capable, which possibly allows for different approaches.

anyone interested in open gl programming? could be an interesting project for someone :)

also, there are improvements that devmiyax is doing to the saturn emulator that should already prove helpful to the pi – eg, using multicore CPUs at full capacity. we may still see a good improvement.

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