This was due to a missing endpoint case that wasn't handled in the port.
The last point still have to be discarded manually because of the
dot/stroke setting of the material.
The first test `ma1.x == -1` is not necessary anymore since the index
buffer do not contain this point (which was rendered using instance
rendering before.
Reviewed By: jbakker
Differential Revision: https://developer.blender.org/D16812
This library contains the needed functions to render GPencil object
geometry. Centralizing these will make it possible for other draw
engines (EEVEE, Overlay) to reuse the same vertex shader code and
possibly the same fragment rejection methods.
