Curves: Port resample node to the new data-block

This commit re-implements the resample curve node to use the new curves
type instead of CurveEval. The largest changes come from the need to
keep track of offsets into the point attribute arrays, and the fact
that the attributes for all curves are stored in a flat array.

Another difference is that a bit more of the logic is handled by
building of the field network inputs. The idea is to let the field
evaluator handle potential optimizations while making the rest of the
code simpler.

When resampling 1 million small poly curves,the node is about 6
times faster compared to 3.1 on my hardware (500ms to 80ms).

This also adds support for Catmull Rom curve inputs.

Differential Revision: https://developer.blender.org/D14435

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/nodes/geometry/node_geometry_util.hh b/source/blender/nodes/geometry/node_geometry_util.hh
index 5b7211e44b4..7af3159bbf8 100644
--- a/source/blender/nodes/geometry/node_geometry_util.hh
+++ b/source/blender/nodes/geometry/node_geometry_util.hh
@@ -81,4 +81,14 @@ void separate_geometry(GeometrySet &geometry_set,
 std::optional<CustomDataType> node_data_type_to_custom_data_type(eNodeSocketDatatype type);
 std::optional<CustomDataType> node_socket_to_custom_data_type(const bNodeSocket &socket);
 
+class SplineLengthFieldInput final : public GeometryFieldInput {
+ public:
+  SplineLengthFieldInput();
+  GVArray get_varray_for_context(const GeometryComponent &component,
+                                 AttributeDomain domain,
+                                 IndexMask mask) const final;
+  uint64_t hash() const override;
+  bool is_equal_to(const fn::FieldNode &other) const override;
+};
+
 }  // namespace blender::nodes