Geometry Nodes: Port most curve primitives to new data-block

Create `Curves` directly, instead of using the conversion from
`CurveEval`. This means that the `tilt` and `radius` attributes
don't need to be allocated. The old behavior is kept by using the
right defaults in the conversion to `CurveEval` later on.

The Bezier segment primitive isn't ported yet, because functions
to provide easy access to built-in attributes used for Bezier curves
haven't been added yet.

Differential Revision: https://developer.blender.org/D14212

1 files changed, 9 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/curves.cc b/source/blender/blenkernel/intern/curves.cc
index c7aaf4718fe..838f7f28e93 100644
--- a/source/blender/blenkernel/intern/curves.cc
+++ b/source/blender/blenkernel/intern/curves.cc
@@ -374,4 +374,13 @@ Curves *curves_new_nomain(const int point_size, const int curves_size)
   return curves;
 }
 
+Curves *curves_new_nomain_single(const int point_size, const CurveType type)
+{
+  Curves *curves = curves_new_nomain(point_size, 1);
+  CurvesGeometry &geometry = CurvesGeometry::wrap(curves->geometry);
+  geometry.offsets().last() = point_size;
+  geometry.curve_types().first() = type;
+  return curves;
+}
+
 }  // namespace blender::bke