WIP: Alembic: Export new Curves object type

@@ -42,0 +56,4 @@
+    case OB_CURVES_LEGACY: {
+      Curve *cu = static_cast<Curve *>(context->object->data);
+      resolution_u = cu->resolu;
+    } break;

@@ -42,3 +67,3 @@
   OCompoundProperty user_props = abc_curve_schema_.getUserProperties();
   OInt16Property user_prop_resolu(user_props, ABC_CURVE_RESOLUTION_U_PROPNAME);
-  user_prop_resolu.set(cu->resolu);
+  user_prop_resolu.set(resolution_u);

@@ -57,3 +82,3 @@
 void ABCCurveWriter::do_write(HierarchyContext &context)
 {
-  Curve *curve = static_cast<Curve *>(context.object->data);
+  Curves *curves;

@@ -60,0 +87,4 @@
+  switch (context.object->type) {
+    case OB_CURVES_LEGACY: {
+      const Curve *legacy_curve = static_cast<Curve *>(context.object->data);
+      converted_curves = std::unique_ptr<Curves, std::function<void(Curves *)>>(

@@ -60,0 +100,4 @@
+      return;
+  }
+
+  const bke::CurvesGeometry &geometry = curves->geometry.wrap();

@@ -60,0 +118,4 @@
+
+  const VArray<bool> cyclic_values = geometry.cyclic();
+  const bool is_cyclic = cyclic_values[0];
+  bool all_same_cyclic_type = std::all_of(

@@ -60,0 +131,4 @@
+  Alembic::AbcGeom::CurveType curve_type = Alembic::AbcGeom::kVariableOrder;
+  Alembic::AbcGeom::CurvePeriodicity periodicity = is_cyclic ? Alembic::AbcGeom::kPeriodic :
+                                                               Alembic::AbcGeom::kNonPeriodic;
+  const int8_t blender_curve_type = geometry.curve_types().first();

@@ -79,2 +171,3 @@
+    const size_t current_vert_count = verts.size();
 
-      const int totpoint = nurbs->pntsu * nurbs->pntsv;
+    switch (blender_curve_type) {

@@ -105,0 +212,4 @@
+          verts.push_back(to_yup_V3f(handles_l[start_point_index]));
+        }
+
+      } break;

@@ -316,0 +343,4 @@
+                                     MutableSpan<float3> positions,
+                                     MutableSpan<float3> handles_left,
+                                     MutableSpan<float3> handles_right,
+                                     const Span<Imath::V3f> alembic_positions)

@@ -72,0 +162,4 @@
+  const Span<float> nurbs_weights = curves.nurbs_weights();
+  const VArray<int8_t> nurbs_orders = curves.nurbs_orders();
+  const bke::AttributeAccessor curve_attributes = curves.attributes();
+  const bke::AttributeReader<float> radii = curve_attributes.lookup<float>("radius",

@@ -60,0 +121,4 @@
+  }
+
+  const VArray<bool> cyclic_values = curves.cyclic();
+  const bool is_cyclic = cyclic_values.is_empty() ? false : cyclic_values.first();

@@ -89,0 +189,4 @@
+       *   control point 1(+ width), right handle 1, left handle 2,
+       *   control point 2(+ width), ...
+       * ] */
+      for (int i_point = start_point_index; i_point < last_point_index; i_point++) {

@@ -89,0 +191,4 @@
+       * ] */
+      for (int i_point = start_point_index; i_point < last_point_index; i_point++) {
+        verts.push_back(to_yup_V3f(positions[i_point]));
+        widths.push_back(radii[last_point_index] * 2.0f);