glGetError and other OpenGL functions are statically linked about remotery

[SoylentGraham]

Out of curiosity, which platforms is glGetError slow on?

[bkaradzic]

For example, extreme case is Native Client, where glGetError serializes GL client and server.

[dwilliamson]

This sounds good but I'm in the middle of Mexico right now and can't pull until we have a more stable internet connection. I'll get this through next week.

[dwilliamson]

OK, this isn't too much of an issue right now:

• On Windows, glGetError is linked if you can already call wglGetProcAddress.
• Native Client isn't hooked up to use OpenGL as its rmtGetProcAddress impl is empty.
• It's a much bigger problem. On Windows you still need to static link for wglGetProcAddress. There's also glXGetProcAddressARB and NSGLGetProcAddress which I have no idea about.

The whole thing does need a bit of a cleanup. How do you get around the wglGetProcAddress issue?

I'll open another issue for calls being slow as their complexities are very different.

[bkaradzic]

glGetError can be loaded with GetProcAddress.

See how I do dynamic loading of GL in bgfx:
https://github.com/bkaradzic/bgfx/blob/master/src/glcontext_wgl.cpp#L15

https://github.com/bkaradzic/bgfx/blob/master/src/glcontext_wgl.cpp#L109

This loads GL 1.0 symbols:
https://github.com/bkaradzic/bgfx/blob/master/src/glcontext_wgl.cpp#L367

[bkaradzic]

Btw, forgot to mention, the reason why I see this issue is because bgfx doesn't link with opengl32.lib (nor d3d9/11/etc.) at all. Everything is dynamically loaded.

[dwilliamson]

Yep, I get that. My game uses multiple DLLs and I want to be able to issue GPU samples outside of the graphics DLLs without linking to the graphics libraries.

Thanks for your help.

[dwilliamson]

Preliminary work on this 1f2c461

[bkaradzic]

What's wrong with GL in one change list. :)

[dwilliamson]

Only Linux left to fix now. Should be able to dlopen libgl.so by the looks of things: https://github.com/ApoorvaJ/Papaya/blob/3808e39b0f45d4ca4972621c847586e4060c042a/src/libs/gl_lite.h#L132

[dwilliamson]

Fixed in c66d2e8