@Isaiah
If I understand the code correctly, your solution would call the
getProcAddress with every OpenGL call.
This wouldn't be very desirable, even if getProcAddress is fast...
Using the native getProcAddress is a nice idea though, with which I played
around as well.
But I think in the end it's better to leave this to a third party library.
I played around with it a little and run into a few platform dependent
inconsistencies quite quickly.
Maybe we can use this as a fall back, if no getProcAddress function is
defined.
@ Mike Innes
Cool, that seems to be exactly what I need. =)
I tried something similar, but it seems like I didn't understand Julia
macros well enough to make it work...
Your solution at least satisfies my simple test case that I came up with.
Good thing is, that I should be able to quickly emit code for the whole
OpenGL package, as I generate all the code automatically anyways.
I keep you updated, if this works out alright!
Best,
Simon
Am Dienstag, 1. April 2014 14:30:12 UTC+2 schrieb Simon Danisch:
>
> Hi,
> I’m working on the OpenGL package and I want to make it finally usable in
> a nice and clean way on all platforms.
> The problem is, that one needs pointer for the GL functions, which you can
> only get, after initialization of the OpenGL context.
> But initializing the context and creating a window shouldn’t be part of
> the OpenGL package.
>
> So I tried two different approaches, which both seem to have their
> downsides:
>
> 1.
> Initialize OpenGL context when including the OpenGL package
> This is bad, because this makes the OpenGL package dependent on some third
> party OpenGL context creation library.
>
> 2.
> Load the functions later with a loading Function.
> Bad, because the function definitions are not visible for any other
> module, that relies on the OpenGL package.
>
> My ideal solution would be, to evaluate a macro when the function is
> called and not when the module is included.
> Like this, I can define all the OpenGL functions already in the OpenGL
> module, and when you call them the first time,
> the right function ptr gets inserted into the ccall, or an error is
> raised, when OpenGL context is not initialized.
>
> this could look like this:
>
>
> module OpenGL
>
> macro getFuncPointer(name::ASCIIString)
> return getProcAddress(name)
> end
>
> glGetString(name::GLenum) = ccall(@getFuncPointer("glGetString"), ...., ....,
> name)
> export glGetString
> end
>
>
> using OpenGL
> ...create OpenGL context
> #define getProcAddress
> global const getProcAddress = glutGetProcAddress # If using GLUT for GL
> context creation
> #call gl Functions
> glGetString(GL_VERSION)
>
> Any ideas how to do this in a clean way?
>
>
> Cheers,
>
> Simon
>
