add net and wire struct; move net update into its file

sim/compile.lua

@@ -2,12 +2,6 @@
 local ffi = FFI or require("ffi")
 Simulation = Simulation or {}
 
-ffi.cdef([[
-	struct Net {
-		
-	};
-]])
-
 function Simulation.compile(sim)
 	-- assemble a list of all nets
 	local all_nets = {}

sim/group.lua

@@ -1,6 +1,19 @@
 
 Group = {}
 
+FFI.cdef[[
+	struct Port;
+	struct Net {
+		bool state;
+		bool fxstate;
+		int updatetick;
+		int internal_ref;
+		int state_num;
+		int num_in_ports_update;
+		struct Port* in_ports_update[1];
+	};
+]]
+
 function Group.new(self, sim)
 	local o = {
 		state = false,
@@ -10,6 +23,8 @@ function Group.new(self, sim)
 		out_ports = {},
 		in_ports = {},
 		
+		state_num = 0,
+	
 		nwires = 0,
 		nout_ports = 0,
 		nin_ports = 0,
@@ -154,3 +169,15 @@ end
 function Group.getsim(group)
 	return group.sim
 end
+
+function Group.update(group)
+	local newstate = false
+	for j, port in pairs(group.out_ports) do
+		newstate = newstate or Port.getstate(port)
+		if newstate then
+			break
+		end
+	end
+	
+	Group.setstate(group, newstate)
+end

sim/port.lua

@@ -17,6 +17,7 @@ Port = {}
 
 FFI.cdef[[
 	struct Gate;
+	struct Net;
 	struct Port {
 		bool state;
 		char type;

sim/simulation.lua

@@ -266,15 +266,7 @@ end
 
 function Simulation.tick(self)
 	for k, group in pairs(self.groupqueue) do
-		local newstate = false
-		for j, port in pairs(group.out_ports) do
-			newstate = newstate or Port.getstate(port)
-			if newstate then
-				break
-			end
-		end
-		
-		Group.setstate(group, newstate)
+		Group.update(group)
 	end
 	self.groupqueue = {}
 	

sim/wire.lua

@@ -1,6 +1,15 @@
 
 Wire = {}
 
+FFI.cdef[[
+	struct Wire {
+		int objref;
+		int layer;
+		struct Net* group;
+		int bounds[6];
+	};
+]]
+
 function Wire.new(self, objref, layer, bounds, sim)
 	local o = {
 		objref = objref,