The Final Drone Grid Game - Beginning Android 3D Game Development - page 366

The m_TimeLastTankOnGrid variable holds the time that a tank enemy was last added to the playfield.

private long m_TimeLastTankOnGrid = 0;

The m_MaxTanksOnPlayField variable holds the maximum number of tanks allowed on the playfield at
one time.

private int m_MaxTanksOnPlayField = 2;

The m_NumberTankRoutes variable holds the total number of tank routes available to select from.

private int m_NumberTankRoutes = 0;

The m_TankRouteIndex variable holds the current index into the available tank routes, which is the
m_TankRoutes array variable.

private int m_TankRouteIndex = 0;

The m_TankRoutes array variable holds the tank routes consisting of groups of waypoints.

private Route[] m_TankRoutes = null;

The GamePlayController( ) constructor initializes the GamePlayController class by setting key class
member variables, such as the arena objects set, the tank fleet, the gravity grid, and the available
tank routes. (See Listing 10-22.)

Listing 10-22. GamePlayController Constructor

GamePlayController(Context iContext,ArenaObjectSet ArenaObjectsSet,TankFleet TankFleet,
GravityGridEx Grid,int NumberTankRoutes,Route[] TankRoutes)
{
m_Context = iContext;

m_ArenaObjectsSet = ArenaObjectsSet;
m_TankFleet = TankFleet;
m_Grid = Grid;

m_NumberTankRoutes = NumberTankRoutes;
m_TankRoutes = TankRoutes;
}

The GenerateRandomGridLocation() generates and returns a random location on the gravity grid.
(See Listing 10-23.)

The function does the following:

1. Gets the minimum x boundary for the gravity grid

2. Gets the maximum x boundary for the gravity grid

3. Finds the difference between the maximum x boundary and the minimum x

boundary