Curves: Interpolate point count in add brush

This commit adds an option to interpolate the number of control points
in new curves based on the count in neighboring existing curves. The
idea is to provide a more automatic default than manually controlling
the number of points in a curve, so users don't have to think about
the resolution quite as much.

Internally, some utilities for creating new curves are extracted to a
new header file. These can be used for the various nodes and operators
that create new curves.

The top-bar UI will be adjusted in a separate patch, probably moving
all of the settings that affect the size and shape of the new curves
into a popover.

Differential Revision: https://developer.blender.org/D14877

1 files changed, 5 insertions, 35 deletions

diff --git a/source/blender/geometry/intern/resample_curves.cc b/source/blender/geometry/intern/resample_curves.cc
index 5eba3ff3b3a..7895225a189 100644
--- a/source/blender/geometry/intern/resample_curves.cc
+++ b/source/blender/geometry/intern/resample_curves.cc
@@ -8,6 +8,7 @@
 
 #include "BKE_attribute_math.hh"
 #include "BKE_curves.hh"
+#include "BKE_curves_utils.hh"
 #include "BKE_geometry_fields.hh"
 
 #include "GEO_resample_curves.hh"
@@ -196,37 +197,6 @@ static void copy_between_curves(const bke::CurvesGeometry &src_curves,
   });
 }
 
-/**
- * Copy the size of every curve in #curve_ranges to the corresponding index in #counts.
- */
-static void fill_curve_counts(const bke::CurvesGeometry &src_curves,
-                              const Span<IndexRange> curve_ranges,
-                              MutableSpan<int> counts)
-{
-  threading::parallel_for(curve_ranges.index_range(), 512, [&](IndexRange ranges_range) {
-    for (const IndexRange curves_range : curve_ranges.slice(ranges_range)) {
-      for (const int i : curves_range) {
-        counts[i] = src_curves.points_for_curve(i).size();
-      }
-    }
-  });
-}
-
-/**
- * Turn an array of sizes into the offset at each index including all previous sizes.
- */
-static void accumulate_counts_to_offsets(MutableSpan<int> counts_to_offsets)
-{
-  int total = 0;
-  for (const int i : counts_to_offsets.index_range().drop_back(1)) {
-    const int count = counts_to_offsets[i];
-    BLI_assert(count > 0);
-    counts_to_offsets[i] = total;
-    total += count;
-  }
-  counts_to_offsets.last() = total;
-}
-
 static Curves *resample_to_uniform(const CurveComponent &src_component,
                                    const fn::Field<bool> &selection_field,
                                    const fn::Field<int> &count_field)
@@ -257,8 +227,8 @@ static Curves *resample_to_uniform(const CurveComponent &src_component,
       src_curves.curves_range(), nullptr);
 
   /* Fill the counts for the curves that aren't selected and accumulate the counts into offsets. */
-  fill_curve_counts(src_curves, unselected_ranges, dst_offsets);
-  accumulate_counts_to_offsets(dst_offsets);
+  bke::curves::fill_curve_counts(src_curves, unselected_ranges, dst_offsets);
+  bke::curves::accumulate_counts_to_offsets(dst_offsets);
   dst_curves.resize(dst_offsets.last(), dst_curves.curves_num());
 
   /* All resampled curves are poly curves. */
@@ -428,8 +398,8 @@ Curves *resample_to_evaluated(const CurveComponent &src_component,
       dst_offsets[i] = src_curves.evaluated_points_for_curve(i).size();
     }
   });
-  fill_curve_counts(src_curves, unselected_ranges, dst_offsets);
-  accumulate_counts_to_offsets(dst_offsets);
+  bke::curves::fill_curve_counts(src_curves, unselected_ranges, dst_offsets);
+  bke::curves::accumulate_counts_to_offsets(dst_offsets);
 
   dst_curves.resize(dst_offsets.last(), dst_curves.curves_num());