Python: Add to_curve method to the object API

This patch adds a to_curve method to the Object ID. This method is
analogous to the to_mesh method. The method can operate on curve and
text objects. For text objects, the text is converted into a 3D Curve ID
and that curve is returned. For curve objects, if apply_modifiers is
true, the spline deform modifiers will be applied and a Curve ID with
the result will be returned, otherwise a copy of the curve will be
returned.

The goal of this addition is to allow the developer to access the splines
of text objects and to get the result of modifier applications which was
otherwise not possible.

Reviewed By: Brecht

Differential Revision: https://developer.blender.org/D10354

1 files changed, 20 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index 9b5a1614dc0..04071282a52 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -1742,6 +1742,7 @@ void BKE_object_free_derived_caches(Object *ob)
   }
 
   BKE_object_to_mesh_clear(ob);
+  BKE_object_to_curve_clear(ob);
   BKE_object_free_curve_cache(ob);
 
   /* Clear grease pencil data. */
@@ -5057,6 +5058,7 @@ void BKE_object_runtime_reset_on_copy(Object *object, const int UNUSED(flag))
   runtime->mesh_deform_eval = NULL;
   runtime->curve_cache = NULL;
   runtime->object_as_temp_mesh = NULL;
+  runtime->object_as_temp_curve = NULL;
   runtime->geometry_set_eval = NULL;
 }
 
@@ -5615,6 +5617,24 @@ void BKE_object_to_mesh_clear(Object *object)
   object->runtime.object_as_temp_mesh = NULL;
 }
 
+Curve *BKE_object_to_curve(Object *object, Depsgraph *depsgraph, bool apply_modifiers)
+{
+  BKE_object_to_curve_clear(object);
+
+  Curve *curve = BKE_curve_new_from_object(object, depsgraph, apply_modifiers);
+  object->runtime.object_as_temp_curve = curve;
+  return curve;
+}
+
+void BKE_object_to_curve_clear(Object *object)
+{
+  if (object->runtime.object_as_temp_curve == NULL) {
+    return;
+  }
+  BKE_id_free(NULL, object->runtime.object_as_temp_curve);
+  object->runtime.object_as_temp_curve = NULL;
+}
+
 void BKE_object_check_uuids_unique_and_report(const Object *object)
 {
   BKE_pose_check_uuids_unique_and_report(object->pose);