I'm doing some research on geometry shaders and am having problems finding code examples/tutorials that does not use one of the extensions introduced before it was core functionality of OpenGL.

I'm looking for more modern approaches that doesn't use an extension.

Can anyone point me in the right direction?

I've already read the spec, but am looking for actually code examples.

I'm doing some research on geometry shaders and am having problems finding code examples/tutorials that does not use one of the extensions introduced before it was core functionality of OpenGL 3.2.

I'm looking for more modern approaches that doesn't use an extension.

Can anyone point me in the right direction?

I've already read the spec, but am looking for actually code examples.