// if using the September 2006 release
if(ship.x + ship.sclX > camera.XEdgeAt(ship.z))
{
   ship.x = camera.XEdgeAt(ship.z) - ship.sclX;
}
else if(ship.x - ship.sclX < -camera.XEdgeAt(ship.z))
{
   ship.x = -camera.XEdgeAt(ship.z) + ship.sclX;
}




// if using before the September 2006 release
float distanceValue = (ship.z - camera.z)/100.0f;

if(ship.x + ship.sclX > camera.xEdge * distanceValue)
{
   ship.x = camera.xEdge * distanceValue - ship.sclX;
}
else if(ship.x - ship.sclX < -camera.XEdgeAt * distanceValue)
{
   ship.x = -camera.xEdge * distanceValue + ship.sclX;
}