Migrate from NS3

NS4 provides the same functionality as NS3, but uses object-oriented approach. It also supports a few unique features which are not available in NS3.

Changes

Objects

The ns3.ObjectID is replaced with ns4.Obj type. The main difference is that ns4.Obj is opaque and can no longer be used or stored as an integer.

It is possible to convert ns4.Obj to/from ns3.ObjectID using the following code:

ns4.AsObj(obj)

ns3.ObjectID(obj.ObjScriptID())

Similar functions are available for ns4.ObjGroup and ns3.ObjectGroupID:

ns4.AsObjGroup(group)

ns3.ObjectGroupID(group.ObjGroupScriptID())

Most object-specific functions are now available on the object itself, instead of a top-level library function:

obj.Enable(false)
obj.Delete()

ns3.ObjectOff(obj)
ns3.Delete(obj)

Object position is now available as a point type, instead of separate X and Y coordinates:

pos := obj.Pos()
x, y := pos.X, pos.Y

x, y := ns3.GetObjectX(obj), ns3.GetObjectY(obj)

Most functions can now accept this new position type instead of a coordinate pair:

pos := obj.Pos()
obj2.HitMelee(pos)

x, y := ns3.GetObjectX(obj), ns3.GetObjectY(obj)
ns3.HitLocation(obj2, x, y)

Position can also be constructed from X and Y values:

obj.HitMelee(ns4.Ptf(10, 20))

ns3.HitLocation(obj, 10, 20)

Waypoints

Similar to objects, waypoints are also represented with opaque ns4.WaypointObj type.

Conversion to/from ns3.WaypointID is still available:

ns4.AsWaypoint(wp)

ns3.WaypointID(wp.WaypointScriptID())

Waypoints now also have methods instead of top-level library functions:

wp.Enable(false)

ns3.WaypointOff(wp)

Position is also returned as a point data type:

pos := wp.Pos()
x, y := pos.X, pos.Y

x, y := ns3.GetWaypointX(obj), ns3.GetWaypointY(obj)

This, in turn, allows using any type that has Pos() method (also known as ns4.Positioner) in places where position is expected:

ns4.CreateObject("Beholder", ns4.Ptf(10, 20))
ns4.CreateObject("Beholder", ns4.GetHost())
ns4.CreateObject("Beholder", ns4.Waypoint("Spot"))

ns3.CreateObject("Beholder", ns3.Waypoint("Spot"))