Rewrite C&C shellmap script in lua.

mods/cnc/maps/shellmap/shellmap.lua

@@ -0,0 +1,44 @@
+
+ticks = 0
+speed = 5
+
+Tick = function()
+	ticks = ticks + 1
+	local t = (ticks + 45) % (360 * speed) * (math.pi / 180) / speed;
+	OpenRA.SetViewportCenterPosition(WPos.op_Addition(viewportOrigin, MakeVec(-15360 * math.sin(t), 4096 * math.cos(t))))
+end
+
+WorldLoaded = function()
+	viewportOrigin = OpenRA.GetViewportCenterPosition()
+	CreateUnitsInTransport(lst1, { "htnk" });
+	CreateUnitsInTransport(lst2, { "mcv" });
+	CreateUnitsInTransport(lst3, { "htnk" });
+
+	local units = { boat1, boat2, boat3, boat4, lst1, lst2, lst3}
+	for i, unit in ipairs(units) do
+		LoopTrack(unit, MakePos(8, unit.Location.Y), MakePos(87, unit.Location.Y))
+	end
+end
+
+LoopTrack = function(actor, left, right)
+	Actor.ScriptedMove(actor, left)
+	Actor.Teleport(actor, right)
+	Actor.CallFunc(actor, function() LoopTrack(actor, left, right) end)
+end
+
+CreateUnitsInTransport = function(transport, passengerNames)
+	local cargo = Actor.Trait(transport, "Cargo")
+	local owner = transport.owner
+	for i, passengerName in ipairs(passengerNames) do
+		cargo:Load(transport, Actor.Create(passengerName, { AddToWorld = false, Owner = owner }))
+	end
+end
+
+-- TODO: The standard library should expose CPos.New() etc
+MakePos = function(x, y)
+	return OpenRA.New("CPos", { {x, "Int32"}, {y, "Int32"} })
+end
+
+MakeVec = function(x, y)
+	return OpenRA.New("WVec", { {x, "Int32"}, {y, "Int32"}, {0, "Int32"} })
+end