This makes it possible to create vertex attributes that efficiently
represent constant values without duplicating the constant for every
vertex. This adds the following new constructors for constant
attributes:
cogl_attribute_new_const_1f
cogl_attribute_new_const_2fv
cogl_attribute_new_const_3fv
cogl_attribute_new_const_4fv
cogl_attribute_new_const_2f
cogl_attribute_new_const_3f
cogl_attribute_new_const_4f
cogl_attribute_new_const_2x2fv
cogl_attribute_new_const_3x3fv
cogl_attribute_new_const_4x4fv
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 6507216f8030e84dcf2e63b8ecfe906ac47f2ca7)
6e379fb54e