(cffi:defcstruct frustum-t)  

The graphene:frustum-t structure represents a volume of space delimited by planes. It is usually employed to represent the field of view of a camera, and can be used to determine whether an object falls within that view, to efficiently remove invisible objects from the render process.

Use the graphene:with-frustum and graphene:with-frustums macros to create and initalize graphene:frustum-t instances.