chest: stay open when empty (#1699)

This is debatable. Let's see how this feels ingame and revert it in case we don't like it.
I like it because I think it gives valuable feedback to the players (and thus can reduce frustration coming from unnecessary actions). But it might also feel like a bug to players.

planet/Objects.ocd/Structures.ocd/Chest.ocd/Script.c

@@ -10,12 +10,15 @@
 #include Library_Ownable
 
 local is_open;
+local has_interaction_menu_open = false;
 
 protected func Construction()
 {
-	PlayAnimation("Open", 1, Anim_Linear(0, 0, 1, 20, ANIM_Hold));
+	// On Construction, the object does not contain anything, so we default to keeping the chest open.
+	PlayAnimation("Open", 5, Anim_Linear(0, 0, GetAnimationLength("Open"), 1, ANIM_Hold));
+	is_open = true;
+	
 	SetProperty("MeshTransformation",Trans_Rotate(RandomX(20,80),0,1,0));
-	is_open = false;
 	return _inherited(...);
 }
 
@@ -35,13 +38,41 @@ protected func RejectCollect()
 public func OnShownInInteractionMenuStart(bool first)
 {
 	if (first)
+	{
 		Open();
+		has_interaction_menu_open = true;
+	}
 }
 
 public func OnShownInInteractionMenuStop(bool last)
 {
 	if (last)
+	{
+		if (ContentsCount() > 0)
+			Close();
+		has_interaction_menu_open = false;
+	}
+}
+
+public func Collection2(object obj)
+{
+	if (is_open && !has_interaction_menu_open)
 		Close();
+	return _inherited(obj, ...);
+}
+
+public func Ejection(object obj)
+{
+	if (ContentsCount() == 0 && !has_interaction_menu_open)
+		Open();
+	return _inherited(obj, ...);
+}
+
+public func ContentsDestruction(object destroyed)
+{
+	if (ContentsCount() <= 1 && !has_interaction_menu_open)
+		Open();
+	return _inherited(destroyed, ...);
 }
 
 private func Open()

planet/Parkour.ocf/Boomshire.ocs/System.ocg/Chest.c

@@ -3,6 +3,15 @@
 public func IsContainer() { return false; }
 public func RejectCollect() { return true; }
 
+// Start the chest closed.
+public func Construction()
+{
+	inherited(...);
+	
+	PlayAnimation("Close", 5, Anim_Linear(0, 0, GetAnimationLength("Close"), 1, ANIM_Hold));
+	is_open = false;
+}
+
 // Never automatically open/close the chest.
 public func OnShownInInteractionMenuStart(bool last) { }
 public func OnShownInInteractionMenuStop(bool last) { }