When associating indices with a CoglPrimitive you are now forced to
specify the number of indices that should be read when drawing.
It's easy to forget to call cogl_primitive_set_n_vertices() after
associating indices with a primitive (and anyway you can see that someone
could be led to believe Cogl can determine that implicitly somewhow) so
this should avoid a lot of mistakes with using the API.
We'd expect that setting indices and updating the n_vertices property
would go hand in hand 99% of the time anyway so this change should
be more convenient as well as less error prone.
This patch adds some documentation for cogl_primitive_set_indices and
cogl_primitive_get/set_n_vertices. It also tries to clarify how the
CoglPrimitive:n_vertices property is updated and what that property
means in relation to other functions too.
https://bugzilla.gnome.org/show_bug.cgi?id=661019
Reviewed-by: Neil Roberts <neil@linux.intel.com>
8cf76ee36b