[Request] Lower the OpenGL version requeriments to reach more hardware?

[vanfanel]

Hi there,

The SonicMania decomp built for the GLFW subsystem requires OpenGL 3.3 (as specified in https://github.com/Rubberduckycooly/RSDKv5-Decompilation/blob/4a458a043dfd6122d11782ad190aac45867e1245/RSDKv5/RSDK/Graphics/GLFW/GLFWRenderDevice.cpp#L53)

However, it can be run in GNU/Linux systems like the Raspberry Pi 4 where the max OpenGL version is 2.1, with: MESA_GL_VERSION_OVERRIDE=3.3 MESA_GLSL_VERSION_OVERRIDE=330 ./RSDKv5

Everything works good that way: There are no features that are missing with OpenGL 2.1, and I believe the OpenGL 3.3 decision was a bit too much, even for the basic CRT-like shaders that the engine supports.

So, would it be possible to have the OpenGL version lowered to 2.1 instead of 3.x? Devices supporting OpenGL 2.1 are much more numerous, and in fact the original game executable runs in them.

NOTE that lowering the GLSL version would also be necessary.