Fix T66452: Convert Curve to Grease Pencil Strokes

This commit adds support to convert curves to Grease Pencil strokes and create the materials too.

Also, there is a new python API. This API is required by the modified SVG import addon to create strokes( see T67065).

All curves selected in one operation are converted in the same Grease Pencil object.

1 files changed, 21 insertions, 0 deletions

diff --git a/source/blender/editors/object/object_add.c b/source/blender/editors/object/object_add.c
index 80d150506ad..80fd137291b 100644
--- a/source/blender/editors/object/object_add.c
+++ b/source/blender/editors/object/object_add.c
@@ -2009,6 +2009,7 @@ void OBJECT_OT_duplicates_make_real(wmOperatorType *ot)
 static const EnumPropertyItem convert_target_items[] = {
     {OB_CURVE, "CURVE", ICON_OUTLINER_OB_CURVE, "Curve from Mesh/Text", ""},
     {OB_MESH, "MESH", ICON_OUTLINER_OB_MESH, "Mesh from Curve/Meta/Surf/Text", ""},
+    {OB_GPENCIL, "GPENCIL", ICON_OUTLINER_OB_GREASEPENCIL, "Grease Pencil from Curve", ""},
     {0, NULL, 0, NULL, NULL},
 };
 
@@ -2133,12 +2134,14 @@ static int convert_exec(bContext *C, wmOperator *op)
   Depsgraph *depsgraph = CTX_data_ensure_evaluated_depsgraph(C);
   Scene *scene = CTX_data_scene(C);
   ViewLayer *view_layer = CTX_data_view_layer(C);
+  View3D *v3d = CTX_wm_view3d(C);
   Base *basen = NULL, *basact = NULL;
   Object *ob1, *obact = CTX_data_active_object(C);
   Curve *cu;
   Nurb *nu;
   MetaBall *mb;
   Mesh *me;
+  Object *gpencil_ob = NULL;
   const short target = RNA_enum_get(op->ptr, "target");
   bool keep_original = RNA_boolean_get(op->ptr, "keep_original");
   int a, mballConverted = 0;
@@ -2380,6 +2383,24 @@ static int convert_exec(bContext *C, wmOperator *op)
         /* meshes doesn't use displist */
         BKE_object_free_curve_cache(newob);
       }
+      else if (target == OB_GPENCIL) {
+        if (ob->type != OB_CURVE) {
+          BKE_report(
+              op->reports, RPT_ERROR, "Convert Surfaces to Grease Pencil is not supported.");
+        }
+        else {
+          /* Create a new grease pencil object only if it was not created before.
+           * All curves selected are converted as strokes of the same grease pencil object.
+           * Nurbs Surface are not supported.
+           */
+          if (gpencil_ob == NULL) {
+            const float *cur = scene->cursor.location;
+            ushort local_view_bits = (v3d && v3d->localvd) ? v3d->local_view_uuid : 0;
+            gpencil_ob = ED_gpencil_add_object(C, scene, cur, local_view_bits);
+          }
+          BKE_gpencil_convert_curve(bmain, scene, gpencil_ob, ob, false, false, true);
+        }
+      }
     }
     else if (ob->type == OB_MBALL && target == OB_MESH) {
       Object *baseob;