/// <summary> Constructor. </summary>
/// <exception cref="ArgumentNullException"> Thrown when one or more required arguments are null. </exception>
/// <param name="worldGrid"> The world grid which should provide the grid data to be watched. </param>
/// <param name="numUnitsWide"> How many units wide the area that should be watched. </param>
/// <param name="numUnitsHigh"> How many units high the area that should be watched. </param>
public WorldGridSlice(WorldGrid worldGrid, int numUnitsWide, int numUnitsHigh)
{
if (worldGrid == null)
{
throw new ArgumentNullException("worldGrid");
}
// we always need to be odd isn't that a statement of life)
if (numUnitsWide % 2 != 1)
{
numUnitsWide = numUnitsWide + 1;
}
if (numUnitsHigh % 2 != 1)
{
numUnitsHigh = numUnitsHigh + 1;
}
// let's make sure we always have valid values
numUnitsWide = Math.Max(numUnitsWide, 5);
numUnitsHigh = Math.Max(numUnitsHigh, 5);
_worldGrid = worldGrid;
_visibleGridItems = new Array2D <SliceUnitData <T> >(numUnitsWide, numUnitsHigh);
// these are used for converting an array index back into a world coordinate
_numUnitsWideHalfThreshold = (_visibleGridItems.Width - 1) / 2;
_numUnitsHighHalfThreshold = (_visibleGridItems.Height - 1) / 2;
}
/// <summary> Default constructor. </summary>
public ViewableChunks(WorldGrid worldGrid, int xRadius, int yRadius)
{
_world = worldGrid;
_xRadius = xRadius;
_yRadius = yRadius;
NumberOfChunksWide = _xRadius * 2 + 1;
NumberOfChunksHigh = _yRadius * 2 + 1;
VisibleChunks = new Array2D <Chunk>(NumberOfChunksWide, NumberOfChunksHigh);
}