[Bf-blender-cvs] [6c4e3a9e517] master: Curves: Deduplicate and parallelize point to curve map creation

[Hans Goudey]

Commit: 6c4e3a9e517840bb69260f2ad46748e1dc655e32
Author: Hans Goudey
Date:   Wed Jan 18 16:41:10 2023 -0600
Branches: master
https://developer.blender.org/rB6c4e3a9e517840bb69260f2ad46748e1dc655e32

Curves: Deduplicate and parallelize point to curve map creation

There is a utility method on `CurvesGeometry` to build a map of the
curve for each point. Use that in two more places and make sure its
implementation is multithreaded, which gives a slight speedup
in a simple test file.

===================================================================

M	source/blender/blenkernel/intern/curves_geometry.cc
M	source/blender/nodes/geometry/nodes/node_geo_duplicate_elements.cc

===================================================================

diff --git a/source/blender/blenkernel/intern/curves_geometry.cc b/source/blender/blenkernel/intern/curves_geometry.cc
index b2cd7cf5cae..0f24d9ea640 100644
--- a/source/blender/blenkernel/intern/curves_geometry.cc
+++ b/source/blender/blenkernel/intern/curves_geometry.cc
@@ -536,9 +536,11 @@ Array<int> CurvesGeometry::point_to_curve_map() const
 {
   const OffsetIndices points_by_curve = this->points_by_curve();
   Array<int> map(this->points_num());
-  for (const int i : this->curves_range()) {
-    map.as_mutable_span().slice(points_by_curve[i]).fill(i);
-  }
+  threading::parallel_for(this->curves_range(), 1024, [&](const IndexRange range) {
+    for (const int i_curve : range) {
+      map.as_mutable_span().slice(points_by_curve[i_curve]).fill(i_curve);
+    }
+  });
   return map;
 }
 
@@ -1075,28 +1077,13 @@ static void copy_with_map(const GSpan src, const Span<int> map, GMutableSpan dst
   });
 }
 
-/**
- * Builds an array that for every point, contains the corresponding curve index.
- */
-static Array<int> build_point_to_curve_map(const CurvesGeometry &curves)
-{
-  const OffsetIndices points_by_curve = curves.points_by_curve();
-  Array<int> point_to_curve_map(curves.points_num());
-  threading::parallel_for(curves.curves_range(), 1024, [&](const IndexRange curves_range) {
-    for (const int i_curve : curves_range) {
-      point_to_curve_map.as_mutable_span().slice(points_by_curve[i_curve]).fill(i_curve);
-    }
-  });
-  return point_to_curve_map;
-}
-
 static CurvesGeometry copy_with_removed_points(
     const CurvesGeometry &curves,
     const IndexMask points_to_delete,
     const AnonymousAttributePropagationInfo &propagation_info)
 {
   /* Use a map from points to curves to facilitate using an #IndexMask input. */
-  const Array<int> point_to_curve_map = build_point_to_curve_map(curves);
+  const Array<int> point_to_curve_map = curves.point_to_curve_map();
 
   const Vector<IndexRange> copy_point_ranges = points_to_delete.extract_ranges_invert(
       curves.points_range());
diff --git a/source/blender/nodes/geometry/nodes/node_geo_duplicate_elements.cc b/source/blender/nodes/geometry/nodes/node_geo_duplicate_elements.cc
index b3017a569eb..480fd516360 100644
--- a/source/blender/nodes/geometry/nodes/node_geo_duplicate_elements.cc
+++ b/source/blender/nodes/geometry/nodes/node_geo_duplicate_elements.cc
@@ -821,14 +821,7 @@ static void duplicate_points_curve(GeometrySet &geometry_set,
   Array<int> offsets = accumulate_counts_to_offsets(selection, counts);
   const int dst_num = offsets.last();
 
-  const OffsetIndices src_points_by_curve = src_curves.points_by_curve();
-  Array<int> point_to_curve_map(src_curves.points_num());
-  threading::parallel_for(src_curves.curves_range(), 1024, [&](const IndexRange range) {
-    for (const int i_curve : range) {
-      const IndexRange points = src_points_by_curve[i_curve];
-      point_to_curve_map.as_mutable_span().slice(points).fill(i_curve);
-    }
-  });
+  const Array<int> point_to_curve_map = src_curves.point_to_curve_map();
 
   Curves *new_curves_id = bke::curves_new_nomain(dst_num, dst_num);
   bke::curves_copy_parameters(src_curves_id, *new_curves_id);