/// <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(nameof(worldGrid));
}
numUnitsWide *= GridCoordinate.WorldToGridMultiplier;
numUnitsHigh *= GridCoordinate.WorldToGridMultiplier;
// we always need to be odd (isn't that a statement of life)
MathUtil.MakeOdd(ref numUnitsWide);
MathUtil.MakeOdd(ref numUnitsHigh);
// 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);
_chunkTracker = new ChunkTracker();
// these are used for converting an array index back into a world coordinate
_numUnitsWideHalfThreshold = (_visibleGridItems.Width - 1) / 2;
_numUnitsHighHalfThreshold = (_visibleGridItems.Height - 1) / 2;
}
/// <summary> Constructor. </summary>
/// <param name="position"> The position of the given chunk. </param>
public Chunk(ChunkCoordinate position)
{
Position = position;
_items = new UnsafeGridItemArray(NumberOfGridItemsWide * NumberOfGridItemsHigh);
AbsoluteIndex = WorldGrid.CalculateAbsoluteChunkIndex(Position.X, Position.Y);
}
