Fix T55645: broken particle Use Count option for instancing objects.

There is now a manual refresh button on the panel to update the list
of objects in case it changes, and it also gets refreshed when changing
the collection or toggling the use count option.

This is a bit more manual but the previous code of refreshing the
list while evaluating the depsgraph was unreliable.

This also fixes it to take properly take into account visibility, and
to work with linked collections for which index writing was missing.

3 files changed, 35 insertions, 0 deletions

diff --git a/source/blender/editors/physics/particle_object.c b/source/blender/editors/physics/particle_object.c
index e531836d744..2f96f4e78e6 100644
--- a/source/blender/editors/physics/particle_object.c
+++ b/source/blender/editors/physics/particle_object.c
@@ -387,6 +387,35 @@ void PARTICLE_OT_target_move_down(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
 }
 
+/************************ refresh dupli objects *********************/
+
+static int dupliob_refresh_exec(bContext *C, wmOperator *UNUSED(op))
+{
+	PointerRNA ptr = CTX_data_pointer_get_type(C, "particle_system", &RNA_ParticleSystem);
+	ParticleSystem *psys= ptr.data;
+
+	if (!psys)
+		return OPERATOR_CANCELLED;
+
+	psys_check_group_weights(psys->part);
+	DEG_id_tag_update(&psys->part->id, OB_RECALC_DATA | PSYS_RECALC_REDO);
+	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE, NULL);
+
+	return OPERATOR_FINISHED;
+}
+
+void PARTICLE_OT_dupliob_refresh(wmOperatorType *ot)
+{
+	ot->name = "Refresh Dupli Objects";
+	ot->idname = "PARTICLE_OT_dupliob_refresh";
+	ot->description = "Refresh list of dupli objects and their weights";
+
+	ot->exec = dupliob_refresh_exec;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER|OPTYPE_UNDO;
+}
+
 /************************ move up particle dupliweight operator *********************/
 
 static int dupliob_move_up_exec(bContext *C, wmOperator *UNUSED(op))
@@ -405,6 +434,7 @@ static int dupliob_move_up_exec(bContext *C, wmOperator *UNUSED(op))
 			BLI_remlink(&part->dupliweights, dw);
 			BLI_insertlinkbefore(&part->dupliweights, dw->prev, dw);
 
+			DEG_id_tag_update(&part->id, OB_RECALC_DATA | PSYS_RECALC_REDO);
 			WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE, NULL);
 			break;
 		}
@@ -444,6 +474,7 @@ static int copy_particle_dupliob_exec(bContext *C, wmOperator *UNUSED(op))
 			dw->flag |= PART_DUPLIW_CURRENT;
 			BLI_addhead(&part->dupliweights, dw);
 
+			DEG_id_tag_update(&part->id, OB_RECALC_DATA | PSYS_RECALC_REDO);
 			WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE, NULL);
 			break;
 		}
@@ -490,6 +521,7 @@ static int remove_particle_dupliob_exec(bContext *C, wmOperator *UNUSED(op))
 	if (dw)
 		dw->flag |= PART_DUPLIW_CURRENT;
 
+	DEG_id_tag_update(&part->id, OB_RECALC_DATA | PSYS_RECALC_REDO);
 	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE, NULL);
 
 	return OPERATOR_FINISHED;
@@ -527,6 +559,7 @@ static int dupliob_move_down_exec(bContext *C, wmOperator *UNUSED(op))
 			BLI_remlink(&part->dupliweights, dw);
 			BLI_insertlinkafter(&part->dupliweights, dw->next, dw);
 
+			DEG_id_tag_update(&part->id, OB_RECALC_DATA | PSYS_RECALC_REDO);
 			WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE, NULL);
 			break;
 		}
diff --git a/source/blender/editors/physics/physics_intern.h b/source/blender/editors/physics/physics_intern.h
index e94f582141b..df688d90e44 100644
--- a/source/blender/editors/physics/physics_intern.h
+++ b/source/blender/editors/physics/physics_intern.h
@@ -95,6 +95,7 @@ void PARTICLE_OT_dupliob_copy(struct wmOperatorType *ot);
 void PARTICLE_OT_dupliob_remove(struct wmOperatorType *ot);
 void PARTICLE_OT_dupliob_move_up(struct wmOperatorType *ot);
 void PARTICLE_OT_dupliob_move_down(struct wmOperatorType *ot);
+void PARTICLE_OT_dupliob_refresh(struct wmOperatorType *ot);
 
 /* particle_boids.c */
 void BOID_OT_rule_add(struct wmOperatorType *ot);
diff --git a/source/blender/editors/physics/physics_ops.c b/source/blender/editors/physics/physics_ops.c
index 033777e905e..db64aa8811c 100644
--- a/source/blender/editors/physics/physics_ops.c
+++ b/source/blender/editors/physics/physics_ops.c
@@ -85,6 +85,7 @@ static void operatortypes_particle(void)
 	WM_operatortype_append(PARTICLE_OT_copy_particle_systems);
 	WM_operatortype_append(PARTICLE_OT_duplicate_particle_system);
 
+	WM_operatortype_append(PARTICLE_OT_dupliob_refresh);
 	WM_operatortype_append(PARTICLE_OT_dupliob_copy);
 	WM_operatortype_append(PARTICLE_OT_dupliob_remove);
 	WM_operatortype_append(PARTICLE_OT_dupliob_move_up);