[GEM-dev] bicubic curve

[cyrille henry]

hello,

i finally had time to work on a new primitive for Gem. I wanted it for almost 10 years!
so, i'm glad to present the surface3d that is a bi-cubic curve.
it's almost like the curve3d primitive, except that the curve pass throw all control points.
(well, i choose not to draw the curve between control point 0 and 1, and control_point_max-1 to control_point_max, because the cubic interpolation is not well defined on this intervals)
an other advantage is that this object is not hardware limited for the number of control point.

the drawback is that it can be quite slow to compute normals.


code is maybe not as clean as one can expect, but it should work.

surface3d is on gem svn.  any comment are welcome.

Cheers
Cyrille