float CASW_Sentry_Top::GetPitchTo(CBaseEntity* pEnt)
{
	if (!pEnt)
		return 0;
	Vector diff = pEnt->WorldSpaceCenter() - GetFiringPosition();
	if (diff.x == 0 && diff.y == 0 && diff.z == 0)
		return 0;

	return UTIL_VecToPitch(diff);	
}
void CPropVehicleManhack::UpdateHead( void )
{
	float yaw = GetPoseParameter( "head_yaw" );
	float pitch = GetPoseParameter( "head_pitch" );

	// If we should be watching our enemy, turn our head
	CNPC_Manhack *pManhack=GetManhack();
	
	if (pManhack != NULL) 
	{
		Vector vehicleEyeOrigin;
		QAngle vehicleEyeAngles;
		GetAttachment( "vehicle_driver_eyes", vehicleEyeOrigin, vehicleEyeAngles );

		// FIXME: cache this
		Vector vBodyDir;
		AngleVectors( vehicleEyeAngles, &vBodyDir );

		Vector	manhackDir = pManhack->GetAbsOrigin() - vehicleEyeOrigin;
		VectorNormalize( manhackDir );
		
		float angle = UTIL_VecToYaw( vBodyDir );
		float angleDiff = UTIL_VecToYaw( manhackDir );
		angleDiff = UTIL_AngleDiff( angleDiff, angle + yaw );

		SetPoseParameter( "head_yaw", UTIL_Approach( yaw + angleDiff, yaw, 1 ) );

		angle = UTIL_VecToPitch( vBodyDir );
		angleDiff = UTIL_VecToPitch( manhackDir );
		angleDiff = UTIL_AngleDiff( angleDiff, angle + pitch );

		SetPoseParameter( "head_pitch", UTIL_Approach( pitch + angleDiff, pitch, 1 ) );
	}
	else
	{
		// Otherwise turn the head back to its normal position
		SetPoseParameter( "head_yaw",	UTIL_Approach( 0, yaw, 10 ) );
		SetPoseParameter( "head_pitch", UTIL_Approach( 0, pitch, 10 ) );
	}
}
static int luasrc_UTIL_VecToPitch (lua_State *L) {
  lua_pushnumber(L, UTIL_VecToPitch(luaL_checkvector(L, 1)));
  return 1;
}