GPencil: "Join Strokes" tool doesn't leave gaps by default now

Previously, it would insert "invisible" points after the endpoints of the strokes,
so that they wouldn't appear to be joined, but that behaviour could also get quite
confusing as you wouldn't be sure whether the strokes were really joined or not.

To keep the previous behaviour, simply enable the "Leave Gaps" option on the operator
after running it. This setting will get saved between runs of the operator.

1 files changed, 17 insertions, 11 deletions

diff --git a/source/blender/editors/gpencil/gpencil_data.c b/source/blender/editors/gpencil/gpencil_data.c
index ee01c6db66f..95680b05a88 100644
--- a/source/blender/editors/gpencil/gpencil_data.c
+++ b/source/blender/editors/gpencil/gpencil_data.c
@@ -1152,7 +1152,7 @@ static void gpencil_stroke_copy_point(bGPDstroke *gps, bGPDspoint *point, float
 }
 
 /* Helper: join two strokes using the shortest distance (reorder stroke if necessary ) */
-static void gpencil_stroke_join_strokes(bGPDstroke *gps_a, bGPDstroke *gps_b)
+static void gpencil_stroke_join_strokes(bGPDstroke *gps_a, bGPDstroke *gps_b, const bool leave_gaps)
 {
 	bGPDspoint point, *pt;
 	int i;
@@ -1179,6 +1179,7 @@ static void gpencil_stroke_join_strokes(bGPDstroke *gps_a, bGPDstroke *gps_b)
 	
 	pt = &gps_b->points[gps_b->totpoints - 1];
 	copy_v3_v3(eb, &pt->x);
+	
 	/* review if need flip stroke B */
 	float ea_sb = len_squared_v3v3(ea, sb);
 	float ea_eb = len_squared_v3v3(ea, eb);
@@ -1187,15 +1188,18 @@ static void gpencil_stroke_join_strokes(bGPDstroke *gps_a, bGPDstroke *gps_b)
 		gpencil_flip_stroke(gps_b);
 	}
 
-	/* 1st: add one tail point to start invisible area */
-	point = gps_a->points[gps_a->totpoints - 1];
-	deltatime = point.time;
-	gpencil_stroke_copy_point(gps_a, &point, delta, 0.0f, 0.0f, 0.0f);
-
-	/* 2nd: add one head point to finish invisible area */
-	point = gps_b->points[0];
-	gpencil_stroke_copy_point(gps_a, &point, delta, 0.0f, 0.0f, deltatime);
+	/* don't visibly link the first and last points? */
+	if (leave_gaps) {
+		/* 1st: add one tail point to start invisible area */
+		point = gps_a->points[gps_a->totpoints - 1];
+		deltatime = point.time;
+		gpencil_stroke_copy_point(gps_a, &point, delta, 0.0f, 0.0f, 0.0f);
 
+		/* 2nd: add one head point to finish invisible area */
+		point = gps_b->points[0];
+		gpencil_stroke_copy_point(gps_a, &point, delta, 0.0f, 0.0f, deltatime);
+	}
+	
 	/* 3rd: add all points */
 	for (i = 0, pt = gps_b->points; i < gps_b->totpoints && pt; i++, pt++) {
 		/* check if still room in buffer */
@@ -1223,7 +1227,8 @@ static int gp_stroke_join_exec(bContext *C, wmOperator *op)
 	bGPDstroke *stroke_b = NULL;
 	bGPDstroke *new_stroke = NULL;
 
-	int type = RNA_enum_get(op->ptr, "type");
+	const int type = RNA_enum_get(op->ptr, "type");
+	const bool leave_gaps = RNA_boolean_get(op->ptr, "leave_gaps");
 
 	/* sanity checks */
 	if (ELEM(NULL, gpd))
@@ -1276,7 +1281,7 @@ static int gp_stroke_join_exec(bContext *C, wmOperator *op)
 						}
 					}
 					/* join new_stroke and stroke B. New stroke will contain all the previous data */
-					gpencil_stroke_join_strokes(new_stroke, stroke_b);
+					gpencil_stroke_join_strokes(new_stroke, stroke_b, leave_gaps);
 
 					/* if join only, delete old strokes */
 					if (type == GP_STROKE_JOIN) {
@@ -1335,6 +1340,7 @@ void GPENCIL_OT_stroke_join(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 
 	ot->prop = RNA_def_enum(ot->srna, "type", join_type, GP_STROKE_JOIN, "Type", "");
+	RNA_def_boolean(ot->srna, "leave_gaps", false, "Leave Gaps", "Leave gaps between joined strokes instead of linking them");
 }
 
 /* ******************* Stroke flip ************************** */