/// <summary>
/// Gets a 3x3 chunk of PartitionTiles from a specific position.
/// </summary>
/// <param name="tileList">A pre-initialized List of PartitionTiles for allocation.</param>
/// <param name="position">Position of the center PartitionTile.</param>
/// <returns>List of valid PartitionTiles within a 3x3 area.</returns>
internal void GetAdjacentTiles(List <PartitionTile> tileList, Vector2 position)
{
PartitionTile t = GetTile(position);
if (t != null)
{
GetAdjacentTiles(tileList, t);
}
}
/// <summary>
/// Gets a 3x3 chunk of PartitionTiles, using a PartitionTile as the centre of the chunk.
/// </summary>
/// <param name="tileList">A pre-initialized List of PartitionTiles for allocation.</param>
/// <param name="tile">The center PartitionTile.</param>
/// <returns>List of valid PartitionTiles within a 3x3 area. NULL if no valid PartitionTiles are found.</returns>
internal void GetAdjacentTiles(List <PartitionTile> tileList, PartitionTile tile)
{
Vector2 partitionTilePos = new Vector2(tile.Bounds.X, tile.Bounds.Y);
Point partitionTileIndex = GetTileIndex(partitionTilePos);
if (partitionTileIndex.X == -1 && partitionTileIndex.Y == -1)
{
return;
}
tileList.Add(tile);
// North
if (partitionTileIndex.Y - 1 >= 0)
{
tileList.Add(GridPartitionTiles[partitionTileIndex.X][partitionTileIndex.Y - 1]);
}
// North east
if (partitionTileIndex.Y - 1 >= 0 && partitionTileIndex.X + 1 < partitionTilesX)
{
tileList.Add(GridPartitionTiles[partitionTileIndex.X + 1][partitionTileIndex.Y - 1]);
}
// East
if (partitionTileIndex.X + 1 < partitionTilesX)
{
tileList.Add(GridPartitionTiles[partitionTileIndex.X + 1][partitionTileIndex.Y]);
}
// South east
if (partitionTileIndex.Y + 1 < partitionTilesY && partitionTileIndex.X + 1 < partitionTilesX)
{
tileList.Add(GridPartitionTiles[partitionTileIndex.X + 1][partitionTileIndex.Y + 1]);
}
// South
if (partitionTileIndex.Y + 1 < partitionTilesY)
{
tileList.Add(GridPartitionTiles[partitionTileIndex.X][partitionTileIndex.Y + 1]);
}
// South west
if (partitionTileIndex.Y + 1 < partitionTilesY && partitionTileIndex.X - 1 >= 0)
{
tileList.Add(GridPartitionTiles[partitionTileIndex.X - 1][partitionTileIndex.Y + 1]);
}
// West
if (partitionTileIndex.X - 1 >= 0)
{
tileList.Add(GridPartitionTiles[partitionTileIndex.X - 1][partitionTileIndex.Y]);
}
// North west
if (partitionTileIndex.Y - 1 >= 0 && partitionTileIndex.X - 1 >= 0)
{
tileList.Add(GridPartitionTiles[partitionTileIndex.X - 1][partitionTileIndex.Y - 1]);
}
}
private bool ShouldPrune()
{
for (int x = 0; x < partitionTilesX; x++)
{
for (int y = 0; y < partitionTilesY; y++)
{
PartitionTile tile = GridPartitionTiles[x][y];
if (tile.PartitionObjects.Count > 0)
{
return(false);
}
}
}
return(true);
}
/// <summary>
/// Gets a list of PartitionTiles inside of a line. Allocates less memory than the standard method.
/// </summary>
/// <param name="tiles">Existing list of PartitionTiles to allocate.</param>
/// <param name="start">Starting point of the line.</param>
/// <param name="end">Destination point of the line.</param>
/// <returns></returns>
internal void GetTilesFromLine(List <PartitionTile> tiles, Vector2 start, Vector2 end)
{
Point pStart = GetTileIndex(start);
Point pEnd = GetTileIndex(end);
Point[] points = null; //Core.Physics.BresenhamLine(pStart, pEnd);
for (int i = 0; i < points.Length; i++)
{
PartitionTile t = GetTile(points[i]);
if (t != null)
{
tiles.Add(GetTile(points[i]));
}
}
}
internal SpatialPartition(int tSize, Rectangle bounds)
{
Bounds = bounds;
Position = new Vector2(bounds.X, bounds.Y);
GridPartitionTiles = null;
partitionTileSize = tSize;
partitionTilesX = bounds.Width / partitionTileSize;
partitionTilesY = bounds.Height / partitionTileSize;
GridPartitionTiles = new PartitionTile[partitionTilesX][];
for (int x = 0; x < partitionTilesX; x++)
{
GridPartitionTiles[x] = new PartitionTile[partitionTilesX];
for (int y = 0; y < partitionTilesY; y++)
{
Rectangle b = new Rectangle(x * partitionTileSize, y * partitionTileSize, partitionTileSize, partitionTileSize);
GridPartitionTiles[x][y] = new PartitionTile(b);
}
}
pruneOffset = SE.Utility.Random.Next(0, 120);
}
/// <summary>
/// Removes a GameObject from the grid system.
/// </summary>
/// <param name="go">GameObject to remove.</param>
internal void Remove(IPartitionObject obj)
{
PartitionTile partitionTile = obj.CurrentPartitionTile;
partitionTile?.Remove(obj);
}
/// <summary>
/// Inserts a GameObject into the grid system.
/// </summary>
/// <param name="go">GameObject to add.</param>
internal void Insert(IPartitionObject obj)
{
PartitionTile partitionTile = GetTile(obj.PartitionPosition - Position);
partitionTile?.Insert(obj);
}
