arcball: directly interleave the cube data w/o any allocations.
arcball: directly interleave the cube data w/o any allocations.

And use the new buffer-filling shorthand.

mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples