Geometry Nodes: Trim curve node selection input and corrections

Correct trim for cyclical curves mentioned in T101379, splitting the
curves if the start/endpoint is at the 'loop point'.

Correct implementation based on comments in D14481, request was made to
use 'foreach_curve_by_type' to computing the point lookups.

Included corrections from D16066 as it may not be a adopted solution.

Exposed selection input by adding it as input to the node.
Note: This is disabled for 3.4 to avoid making UI changes in Bcon3.

Differential Revision: https://developer.blender.org/D16161

1 files changed, 29 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/curves_utils.cc b/source/blender/blenkernel/intern/curves_utils.cc
index f5a69a995a3..2b13a7d3c8a 100644
--- a/source/blender/blenkernel/intern/curves_utils.cc
+++ b/source/blender/blenkernel/intern/curves_utils.cc
@@ -128,6 +128,18 @@ IndexMask indices_for_type(const VArray<int8_t> &types,
       selection, 4096, r_indices, [&](const int index) { return types_span[index] == type; });
 }
 
+void indices_for_each_type(const VArray<int8_t> &types,
+                           const std::array<int, CURVE_TYPES_NUM> &counts,
+                           const IndexMask selection,
+                           std::array<IndexMask, CURVE_TYPES_NUM> &r_type_masks,
+                           std::array<Vector<int64_t>, CURVE_TYPES_NUM> &r_type_indices)
+{
+  for (const int64_t curve_type : IndexRange(CURVE_TYPES_NUM)) {
+    r_type_masks[curve_type] = indices_for_type(
+        types, counts, CurveType(curve_type), selection, r_type_indices[curve_type]);
+  }
+}
+
 void foreach_curve_by_type(const VArray<int8_t> &types,
                            const std::array<int, CURVE_TYPES_NUM> &counts,
                            const IndexMask selection,
@@ -150,4 +162,21 @@ void foreach_curve_by_type(const VArray<int8_t> &types,
   call_if_not_empty(CURVE_TYPE_NURBS, nurbs_fn);
 }
 
+void foreach_curve_by_type_mask(const std::array<IndexMask, CURVE_TYPES_NUM> &curve_type_mask,
+                                FunctionRef<void(IndexMask)> catmull_rom_fn,
+                                FunctionRef<void(IndexMask)> poly_fn,
+                                FunctionRef<void(IndexMask)> bezier_fn,
+                                FunctionRef<void(IndexMask)> nurbs_fn)
+{
+  auto call_if_not_empty = [&](const IndexMask curve_type_mask, FunctionRef<void(IndexMask)> fn) {
+    if (!curve_type_mask.is_empty()) {
+      fn(curve_type_mask);
+    }
+  };
+  call_if_not_empty(curve_type_mask[0], catmull_rom_fn);
+  call_if_not_empty(curve_type_mask[1], poly_fn);
+  call_if_not_empty(curve_type_mask[2], bezier_fn);
+  call_if_not_empty(curve_type_mask[3], nurbs_fn);
+}
+
 }  // namespace blender::bke::curves