Geometry Nodes: Begin conversion to new curves

This commit changes `CurveComponent` to store the new curve
type by adding conversions to and from `CurveEval` in most nodes.
This will temporarily make performance of curves in geometry nodes
much worse, but as functionality is implemented for the new type
and it is used in more places, performance will become better than
before.

We still use `CurveEval` for drawing curves, because the new `Curves`
data-block has no evaluated points yet. So the `Curve` ID is still
generated for rendering in the same way as before. It's also still
needed for drawing curve object edit mode overlays.

The old curve component isn't removed yet, because it is still used
to implement the conversions to and from `CurveEval`.

A few more attributes are added to make this possible:
- `nurbs_weight`: The weight for each control point on NURBS curves.
- `nurbs_order`: The order of the NURBS curve
- `knots_mode`: Necessary for conversion, not defined yet.
- `handle_type_{left/right}`: An 8 bit integer attribute.

Differential Revision: https://developer.blender.org/D14145

1 files changed, 20 insertions, 19 deletions

diff --git a/source/blender/geometry/intern/realize_instances.cc b/source/blender/geometry/intern/realize_instances.cc
index c98bd9d6b74..149ae70dda1 100644
--- a/source/blender/geometry/intern/realize_instances.cc
+++ b/source/blender/geometry/intern/realize_instances.cc
@@ -13,6 +13,7 @@
 #include "BLI_task.hh"
 
 #include "BKE_collection.h"
+#include "BKE_curves.hh"
 #include "BKE_geometry_set_instances.hh"
 #include "BKE_material.h"
 #include "BKE_mesh.h"
@@ -118,7 +119,7 @@ struct RealizeMeshTask {
 };
 
 struct RealizeCurveInfo {
-  const CurveEval *curve = nullptr;
+  const Curves *curves;
   /**
    * Matches the order in #AllCurvesInfo.attributes. For point attributes, the `std::optional`
    * will be empty.
@@ -163,7 +164,7 @@ struct AllCurvesInfo {
   /** Ordering of all attributes that are propagated to the output curve generically. */
   OrderedAttributes attributes;
   /** Ordering of the original curves that are joined. */
-  VectorSet<const CurveEval *> order;
+  VectorSet<const Curves *> order;
   /** Preprocessed data about every original curve. This is ordered by #order. */
   Array<RealizeCurveInfo> realize_info;
   bool create_id_attribute = false;
@@ -443,16 +444,16 @@ static void gather_realize_tasks_recursive(GatherTasksInfo &gather_info,
       }
       case GEO_COMPONENT_TYPE_CURVE: {
         const CurveComponent &curve_component = *static_cast<const CurveComponent *>(component);
-        const CurveEval *curve = curve_component.get_for_read();
-        if (curve != nullptr && !curve->splines().is_empty()) {
-          const int curve_index = gather_info.curves.order.index_of(curve);
+        const Curves *curves = curve_component.get_for_read();
+        if (curves != nullptr && curves->geometry.curve_size > 0) {
+          const int curve_index = gather_info.curves.order.index_of(curves);
           const RealizeCurveInfo &curve_info = gather_info.curves.realize_info[curve_index];
           gather_info.r_tasks.curve_tasks.append({gather_info.r_offsets.spline_offset,
                                                   &curve_info,
                                                   base_transform,
                                                   base_instance_context.curves,
                                                   base_instance_context.id});
-          gather_info.r_offsets.spline_offset += curve->splines().size();
+          gather_info.r_offsets.spline_offset += curves->geometry.curve_size;
         }
         break;
       }
@@ -1038,11 +1039,11 @@ static OrderedAttributes gather_generic_curve_attributes_to_propagate(
 }
 
 static void gather_curves_to_realize(const GeometrySet &geometry_set,
-                                     VectorSet<const CurveEval *> &r_curves)
+                                     VectorSet<const Curves *> &r_curves)
 {
-  if (const CurveEval *curve = geometry_set.get_curve_for_read()) {
-    if (!curve->splines().is_empty()) {
-      r_curves.add(curve);
+  if (const Curves *curves = geometry_set.get_curve_for_read()) {
+    if (curves->geometry.curve_size != 0) {
+      r_curves.add(curves);
     }
   }
   if (const InstancesComponent *instances =
@@ -1064,12 +1065,12 @@ static AllCurvesInfo preprocess_curves(const GeometrySet &geometry_set,
   info.realize_info.reinitialize(info.order.size());
   for (const int curve_index : info.realize_info.index_range()) {
     RealizeCurveInfo &curve_info = info.realize_info[curve_index];
-    const CurveEval *curve = info.order[curve_index];
-    curve_info.curve = curve;
+    const Curves *curves = info.order[curve_index];
+    curve_info.curves = curves;
 
     /* Access attributes. */
     CurveComponent component;
-    component.replace(const_cast<CurveEval *>(curve), GeometryOwnershipType::ReadOnly);
+    component.replace(const_cast<Curves *>(curves), GeometryOwnershipType::ReadOnly);
     curve_info.spline_attributes.reinitialize(info.attributes.size());
     for (const int attribute_index : info.attributes.index_range()) {
       const AttributeDomain domain = info.attributes.kinds[attribute_index].domain;
@@ -1095,9 +1096,9 @@ static void execute_realize_curve_task(const RealizeInstancesOptions &options,
                                        MutableSpan<GMutableSpan> dst_spline_attributes)
 {
   const RealizeCurveInfo &curve_info = *task.curve_info;
-  const CurveEval &curve = *curve_info.curve;
+  const std::unique_ptr<CurveEval> curve = curves_to_curve_eval(*curve_info.curves);
 
-  const Span<SplinePtr> src_splines = curve.splines();
+  const Span<SplinePtr> src_splines = curve->splines();
 
   /* Initialize point attributes. */
   threading::parallel_for(src_splines.index_range(), 100, [&](const IndexRange src_spline_range) {
@@ -1206,12 +1207,12 @@ static void execute_realize_curve_tasks(const RealizeInstancesOptions &options,
   }
 
   const RealizeCurveTask &last_task = tasks.last();
-  const CurveEval &last_curve = *last_task.curve_info->curve;
-  const int tot_splines = last_task.start_spline_index + last_curve.splines().size();
+  const Curves &last_curves = *last_task.curve_info->curves;
+  const int tot_splines = last_task.start_spline_index + last_curves.geometry.curve_size;
 
   Array<SplinePtr> dst_splines(tot_splines);
 
-  CurveEval *dst_curve = new CurveEval();
+  std::unique_ptr<CurveEval> dst_curve = std::make_unique<CurveEval>();
   dst_curve->attributes.reallocate(tot_splines);
   CustomDataAttributes &spline_attributes = dst_curve->attributes;
 
@@ -1242,7 +1243,7 @@ static void execute_realize_curve_tasks(const RealizeInstancesOptions &options,
   dst_curve->add_splines(dst_splines);
 
   CurveComponent &dst_component = r_realized_geometry.get_component_for_write<CurveComponent>();
-  dst_component.replace(dst_curve);
+  dst_component.replace(curve_eval_to_curves(*dst_curve));
 }
 
 /** \} */