Curves: support symmetry in curves sculpting brushes

This adds support for X/Y/Z symmetry for all brushes in curves
sculpt mode. In theory this can be extended to support radial
symmetry, but that's not part of this patch.

It works by essentially applying a brush stroke multiple with
different transforms. This is similiar to how symmetry works in
mesh sculpt mode, but is quite different from how it worked in
the old hair system (there it tried to find matching hair strands
on both sides of the surface; if none was found, symmetry did
not work).

Differential Revision: https://developer.blender.org/D14795

1 files changed, 16 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_curves.c b/source/blender/makesrna/intern/rna_curves.c
index 7a1a368551f..2dc568d0b8a 100644
--- a/source/blender/makesrna/intern/rna_curves.c
+++ b/source/blender/makesrna/intern/rna_curves.c
@@ -274,6 +274,22 @@ static void rna_def_curves(BlenderRNA *brna)
   RNA_def_property_ui_text(prop, "Surface", "Mesh object that the curves can be attached to");
   RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, NULL);
 
+  /* Symmetry. */
+  prop = RNA_def_property(srna, "use_mirror_x", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "symmetry", CURVES_SYMMETRY_X);
+  RNA_def_property_ui_text(prop, "X", "Enable symmetry in the X axis");
+  RNA_def_property_update(prop, 0, "rna_Mesh_update_draw");
+
+  prop = RNA_def_property(srna, "use_mirror_y", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "symmetry", CURVES_SYMMETRY_Y);
+  RNA_def_property_ui_text(prop, "Y", "Enable symmetry in the Y axis");
+  RNA_def_property_update(prop, 0, "rna_Mesh_update_draw");
+
+  prop = RNA_def_property(srna, "use_mirror_z", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "symmetry", CURVES_SYMMETRY_Z);
+  RNA_def_property_ui_text(prop, "Z", "Enable symmetry in the Z axis");
+  RNA_def_property_update(prop, 0, "rna_Mesh_update_draw");
+
   /* attributes */
   rna_def_attributes_common(srna);