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, 4 insertions, 9 deletions

diff --git a/source/blender/editors/gpencil/gpencil_add_stroke.c b/source/blender/editors/gpencil/gpencil_add_stroke.c
index 8b261bf798b..c56cb94c58d 100644
--- a/source/blender/editors/gpencil/gpencil_add_stroke.c
+++ b/source/blender/editors/gpencil/gpencil_add_stroke.c
@@ -60,11 +60,10 @@ static int gp_stroke_material(
 		}
 	}
 
+	int idx;
+
 	/* create a new one */
-	BKE_object_material_slot_add(bmain, ob);
-	ma = BKE_material_add_gpencil(bmain, pct->name);
-	assign_material(bmain, ob, ma, ob->totcol, BKE_MAT_ASSIGN_USERPREF);
-	id_us_min(&ma->id);
+	ma = BKE_gpencil_handle_new_material(bmain, ob, pct->name, &idx);
 
 	copy_v4_v4(ma->gp_style->stroke_rgba, pct->line);
 	copy_v4_v4(ma->gp_style->fill_rgba, pct->fill);
@@ -73,7 +72,7 @@ static int gp_stroke_material(
 		ma->gp_style->flag |= GP_STYLE_FILL_SHOW;
 	}
 
-	return BKE_gpencil_get_material_index(ob, ma) - 1;
+	return idx;
 }
 
 /* ***************************************************************** */
@@ -231,10 +230,6 @@ void ED_gpencil_create_stroke(bContext *C, Object *ob, float mat[4][4])
 
 	/* set first color as active and in brushes */
 	ob->actcol = color_black + 1;
-	Material *ma = give_current_material(ob, ob->actcol);
-	if (ma != NULL) {
-		BKE_brush_update_material(bmain, ma, NULL);
-	}
 
 	/* layers */
 	bGPDlayer *colors = BKE_gpencil_layer_addnew(gpd, "Colors", false);