Curves: Further implementation of new curves data structure

The general idea here is to wrap the `CurvesGeometry` DNA struct
with a C++ class that can do most of the heavy lifting for the curve
geometry. Using a C++ class allows easier ways to group methods, easier
const correctness, and code that's more readable and faster to write.
This way, it works much more like a version of `CurveEval` that uses
more efficient attribute storage.

This commit adds the structure of some yet-to-be-implemented code,
the largest thing being mutexes and vectors meant to hold lazily
calculated evaluated positions, tangents, and normals. That part might
change slightly, but it's helpful to be able to see the direction this
commit is aiming in. In particular, the inherently single-threaded
accumulated lengths and Bezier evaluated point offsets might be cached.

Ref T95355

Differential Revision: https://developer.blender.org/D14054

1 files changed, 3 insertions, 5 deletions

diff --git a/source/blender/blenkernel/BKE_curves.h b/source/blender/blenkernel/BKE_curves.h
index 2cce15fbfd6..88bb1c67fd1 100644
--- a/source/blender/blenkernel/BKE_curves.h
+++ b/source/blender/blenkernel/BKE_curves.h
@@ -2,9 +2,11 @@
 
 #pragma once
 
+#include "DNA_curves_types.h"
+
 /** \file
  * \ingroup bke
- * \brief Low-level operations for curves.
+ * \brief Low-level operations for curves that cannot be defined in the C++ header yet.
  */
 
 #ifdef __cplusplus
@@ -23,14 +25,10 @@ void *BKE_curves_add(struct Main *bmain, const char *name);
 
 struct BoundBox *BKE_curves_boundbox_get(struct Object *ob);
 
-void BKE_curves_update_customdata_pointers(struct Curves *curves);
 bool BKE_curves_customdata_required(struct Curves *curves, struct CustomDataLayer *layer);
 
 /* Depsgraph */
 
-struct Curves *BKE_curves_new_for_eval(const struct Curves *curves_src,
-                                       int totpoint,
-                                       int totcurve);
 struct Curves *BKE_curves_copy_for_eval(struct Curves *curves_src, bool reference);
 
 void BKE_curves_data_update(struct Depsgraph *depsgraph,