GPencil: Only brushes with pinned materials have materials

Using GP_BRUSH_MATERIAL_PINNED to switch between active material and brush material, instead of updating all brushes on active material changes. This will allow brushes to have no material and therefore to not inflate the user count.

This fix T62465.

Patch contributed by @matc
Reviewers: @brecht @antoniov @billreynish @mendio

1 files changed, 5 insertions, 25 deletions

diff --git a/source/blender/editors/gpencil/gpencil_data.c b/source/blender/editors/gpencil/gpencil_data.c
index 2cdd772f726..a8b31b20182 100644
--- a/source/blender/editors/gpencil/gpencil_data.c
+++ b/source/blender/editors/gpencil/gpencil_data.c
@@ -514,15 +514,10 @@ static int gp_layer_duplicate_object_exec(bContext *C, wmOperator *op)
 			 * otherwise add the slot with the material
 			 */
 			Material *ma_src = give_current_material(ob_src, gps_src->mat_nr + 1);
-			int idx = BKE_gpencil_get_material_index(ob_dst, ma_src);
-			if (idx == 0) {
-				BKE_object_material_slot_add(bmain, ob_dst);
-				assign_material(bmain, ob_dst, ma_src, ob_dst->totcol, BKE_MAT_ASSIGN_USERPREF);
-				idx = ob_dst->totcol;
-			}
+			int idx = BKE_gpencil_handle_material(bmain, ob_dst, ma_src);
 
 			/* reasign the stroke material to the right slot in destination object */
-			gps_dst->mat_nr = idx - 1;
+			gps_dst->mat_nr = idx;
 
 			/* add new stroke to frame */
 			BLI_addtail(&gpf_dst->strokes, gps_dst);
@@ -1377,7 +1372,7 @@ static int gp_stroke_change_color_exec(bContext *C, wmOperator *op)
 		}
 	}
 	/* try to find slot */
-	int idx = BKE_gpencil_get_material_index(ob, ma) - 1;
+	int idx = BKE_gpencil_get_material_index(ob, ma);
 	if (idx < 0) {
 		return OPERATOR_CANCELLED;
 	}
@@ -2052,10 +2047,7 @@ int ED_gpencil_join_objects_exec(bContext *C, wmOperator *op)
 
 				for (short i = 0; i < *totcol; i++) {
 					Material *tmp_ma = give_current_material(ob_src, i + 1);
-					if (BKE_gpencil_get_material_index(ob_dst, tmp_ma) == 0) {
-						BKE_object_material_slot_add(bmain, ob_dst);
-						assign_material(bmain, ob_dst, tmp_ma, ob_dst->totcol, BKE_MAT_ASSIGN_USERPREF);
-					}
+					BKE_gpencil_handle_material(bmain, ob_dst, tmp_ma);
 				}
 
 				/* duplicate bGPDlayers  */
@@ -2085,24 +2077,12 @@ int ED_gpencil_join_objects_exec(bContext *C, wmOperator *op)
 					invert_m4_m4(inverse_diff_mat, diff_mat);
 
 					Material *ma_src = NULL;
-					int idx;
 					for (bGPDframe *gpf = gpl_new->frames.first; gpf; gpf = gpf->next) {
 						for (bGPDstroke *gps = gpf->strokes.first; gps; gps = gps->next) {
 
 							/* reasign material. Look old material and try to find in dst */
 							ma_src = give_current_material(ob_src, gps->mat_nr + 1);
-							if (ma_src != NULL) {
-								idx = BKE_gpencil_get_material_index(ob_dst, ma_src);
-								if (idx > 0) {
-									gps->mat_nr = idx - 1;
-								}
-								else {
-									gps->mat_nr = 0;
-								}
-							}
-							else {
-								gps->mat_nr = 0;
-							}
+							gps->mat_nr = BKE_gpencil_handle_material(bmain, ob_dst, ma_src);
 
 							bGPDspoint *pt;
 							int i;