Geometry Nodes: Curve Set Spline Type

This node sets the selected (or all) splines in curve to a chosen target
spline type. Poly, Bezier, and NURB splines can be converted to any of
the other types. This is meant to be a building block node, useful in
many procedural situations.

In the future the node could be optimized with multi-threading, or by
avoiding copying in many cases, either by retrieving the curve for write
access or by passing the raw vectors to the new splines where possible.

With edits from Hans Goudey (@HooglyBoogly)

Differential Revision: https://developer.blender.org/D12013

source/blender/blenkernel/intern/node.cc

@@ -5149,6 +5149,7 @@ static void registerGeometryNodes()
   register_node_type_geo_curve_resample();
   register_node_type_geo_curve_reverse();
   register_node_type_geo_curve_set_handles();
+  register_node_type_geo_curve_spline_type();
   register_node_type_geo_curve_subdivide();
   register_node_type_geo_curve_to_mesh();
   register_node_type_geo_curve_to_points();