Added ladders.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@3880 316c924e-a436-60f5-8080-3fe189b3f50e

code/game/objects/ladders.dm

@@ -0,0 +1,69 @@
+/obj/structure/ladder
+	name = "ladder"
+	desc = "A sturdy metal ladder."
+	icon = 'structures.dmi'
+	icon_state = "ladder11"
+	var/id = null
+	var/height = 0							//the 'height' of the ladder. higher numbers are considered physically higher
+	var/obj/structure/ladder/down = null	//the ladder below this one
+	var/obj/structure/ladder/up = null		//the ladder above this one
+
+/obj/structure/ladder/New()
+	spawn(8)
+		for(var/obj/structure/ladder/L in world)
+			if(L.id == id)
+				if(L.height == (height - 1))
+					down = L
+					continue
+				if(L.height == (height + 1))
+					up = L
+					continue
+
+			if(up && down)	//if both our connections are filled
+				break
+		update_icon()
+
+/obj/structure/ladder/update_icon()
+	if(up && down)
+		icon_state = "ladder11"
+
+	else if(up)
+		icon_state = "ladder10"
+
+	else if(down)
+		icon_state = "ladder01"
+
+	else	//wtf make your ladders properly assholes
+		icon_state = "ladder00"
+
+/obj/structure/ladder/attack_hand(mob/user as mob)
+	if(up && down)
+		switch( alert("Go up or down the ladder?", "Ladder", "Up", "Down", "Cancel") )
+			if("Up")
+				user.visible_message("<span class='notice'>[user] climbs up \the [src]!</span>")
+				user.loc = get_turf(up)
+				up.add_fingerprint(user)
+			if("Down")
+				user.visible_message("<span class='notice'>[user] climbs down \the [src]!</span>")
+				user.loc = get_turf(down)
+				down.add_fingerprint(user)
+			if("Cancel")
+				return
+
+	else if(up)
+		user.visible_message("<span class='notice'>[user] climbs up \the [src]!</span>")
+		user.loc = get_turf(up)
+		up.add_fingerprint(user)
+
+	else if(down)
+		user.visible_message("<span class='notice'>[user] climbs down \the [src]!</span>")
+		user.loc = get_turf(down)
+		down.add_fingerprint(user)
+
+	add_fingerprint(user)
+
+/obj/structure/ladder/attack_paw(mob/user as mob)
+	return attack_hand(user)
+
+/obj/structure/ladder/attackby(obj/item/weapon/W, mob/user as mob)
+	return attack_hand(user)