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, 12 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_generic_span.hh b/source/blender/blenlib/BLI_generic_span.hh
index f4f93735e06..4c0bfc83ba8 100644
--- a/source/blender/blenlib/BLI_generic_span.hh
+++ b/source/blender/blenlib/BLI_generic_span.hh
@@ -164,6 +164,18 @@ class GMutableSpan {
   {
     return this->slice(range.start(), range.size());
   }
+
+  /**
+   * Copy all values from another span into this span. This invokes undefined behavior when the
+   * destination contains uninitialized data and T is not trivially copy constructible.
+   * The size of both spans is expected to be the same.
+   */
+  void copy_from(GSpan values)
+  {
+    BLI_assert(type_ == &values.type());
+    BLI_assert(size_ == values.size());
+    type_->copy_assign_n(values.data(), data_, size_);
+  }
 };
 
 }  // namespace blender