Geometry Nodes: Port the trim curve node to the new data-block

The trim functionality is implemented in the geometry module, and
generalized a bit to be potentially useful for bisecting in the future.
The implementation is based on a helper type called `IndexRangeCyclic`
which allows iteration over all control points between two points on a
curve.

Catmull Rom curves are now supported-- trimmed without resampling first.
However, maintaining the exact shape is not possible. NURBS splines are
still converted to polylines using the evaluated curve concept.

Performance is equivalent or faster then a 3.1 build with regards to
node timings. Compared to 3.3 and 3.2, it's easy to observe test cases
where the node is at least 3 or 4 times faster.

Differential Revision: https://developer.blender.org/D14481

1 files changed, 32 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/attribute_access.cc b/source/blender/blenkernel/intern/attribute_access.cc
index 27c54a3d4a7..1e237da8119 100644
--- a/source/blender/blenkernel/intern/attribute_access.cc
+++ b/source/blender/blenkernel/intern/attribute_access.cc
@@ -14,6 +14,7 @@
 #include "DNA_meshdata_types.h"
 #include "DNA_pointcloud_types.h"
 
+#include "BLI_array_utils.hh"
 #include "BLI_color.hh"
 #include "BLI_math_vec_types.hh"
 #include "BLI_span.hh"
@@ -974,6 +975,37 @@ Vector<AttributeTransferData> retrieve_attributes_for_transfer(
   return attributes;
 }
 
+void copy_attribute_domain(const AttributeAccessor src_attributes,
+                           MutableAttributeAccessor dst_attributes,
+                           const IndexMask selection,
+                           const eAttrDomain domain,
+                           const Set<std::string> &skip)
+{
+  src_attributes.for_all(
+      [&](const bke::AttributeIDRef &id, const bke::AttributeMetaData &meta_data) {
+        if (meta_data.domain != domain) {
+          return true;
+        }
+        if (id.is_named() && skip.contains(id.name())) {
+          return true;
+        }
+        if (!id.should_be_kept()) {
+          return true;
+        }
+
+        const GVArray src = src_attributes.lookup(id, meta_data.domain);
+        BLI_assert(src);
+
+        /* Copy attribute. */
+        GSpanAttributeWriter dst = dst_attributes.lookup_or_add_for_write_only_span(
+            id, domain, meta_data.data_type);
+        array_utils::copy(src, selection, dst.span);
+        dst.finish();
+
+        return true;
+      });
+}
+
 }  // namespace blender::bke
 
 /** \} */