pygame.examples.glcube updated to use 'modern' API.

[MyreMylar]

My attempt to update the gl cube example to show how you can switch the context profile.

So it actually works I also included a modern gl version of the gl cube as close as I could make it to the original.

This finishes fixing issue #85

[lgtm-com]

This pull request introduces 2 alerts when merging aa98938 into ea4a028 - view on LGTM.com

new alerts:

• 2 for Unused import

[robertpfeiffer]

Looks good. I ported glcube to modernGL, but your example seems to be the better way to go.

[illume]

Nice one.

I wonder if we should just remove the old OpenGL style code in here so it's easier to read? Then the _modern parts could be removed.

I guess OpenGL.arrays.vbo could be used for the vertex buffers instead to avoid the ctypes import. Probably could use a few doc strings/comments in those transform functions.

[MyreMylar]

OpenGL.arrays.vbo

I looked at the source code for this and it imports ctypes:
https://bazaar.launchpad.net/~mcfletch/pyopengl/trunk/view/head:/OpenGL/arrays/vbo.py#L38

So I'm not sure we'd be gaining anything by switching - it seems to be pretty much the same code in a wrapper. Not an openGL expert though.

I wonder if we should just remove the old OpenGL style code in here so it's easier to read? Then the _modern parts could be removed.

The reason I kept the old parts is because the original point of updating the gl cube example was to show that you could switch the core context profile - in these lines:

gl_version = (2, 0)  # GL Version number (Major, Minor)

# By setting these attributes we can choose which Open GL Profile
# to use, profiles greater than 3.2 use a different rendering path
pg.display.gl_set_attribute(pg.GL_CONTEXT_MAJOR_VERSION, gl_version[0])
pg.display.gl_set_attribute(pg.GL_CONTEXT_MINOR_VERSION, gl_version[1])
pg.display.gl_set_attribute(pg.GL_CONTEXT_PROFILE_MASK,
                            pg.GL_CONTEXT_PROFILE_CORE)

..and I noticed that switching it higher than 3.1 didn't work because of the change between old gl and modern gl. If we remove the old style code, won't we just have the same problem in the other direction, where if you set the profile below 3 it won't work?

Probably could use a few doc strings/comments in those transform functions.

Yes, I will add some.

[illume]

Awesome :)