/// <summary>
/// Fills list of TilePerims of tiles in a TileMap.
/// </summary>
/// <param name="tileMap">The TileMap which we are grabbing tiles from</param>
/// <returns>A list containing the TilePerims in the input TileMap</returns>
private static List <TilePerim> _FillTiles(TileMap tileMap)
{
var tilePerims = new List <TilePerim>();
var usedCells = new List <Vector2>(tileMap.GetUsedCells().OfType <Vector2>()); //thanks to godot's C# api array being non-typed i have to commit this atrocity
for (int i = 0; i < usedCells.Count; i++)
{
Vector2 cell = usedCells[i];
Vector2 botCoord = tileMap.MapToWorld(cell); //Thanks to graphics in general using reverse Y axis, the bottom coordinate actually has the HIGHEST y-value
int cellID = tileMap.GetCellv(cell);
Vector2 originCoord = botCoord - (new Vector2((float)Globals.TileWidth / 2, 0)) + tileMap.TileSet.TileGetTextureOffset(cellID);
NavigationPolygon navPoly = tileMap.TileSet.TileGetNavigationPolygon(cellID);
Vector2[] vertices = _ShiftVertices(navPoly.Vertices, originCoord);
var tilePerim = new TilePerim(vertices, cell, i);
tilePerims.Add(tilePerim);
}
return(tilePerims);
}
/// <summary>
/// Flood files TilePerims via DFS, coloring them, in order to find how they are grouped up.
/// </summary>
/// <param name="adjMatrix">Adjacency matrix of TilePerims.</param>
/// <param name="tilePerims"></param>
/// <param name="thisTile">The tile this function is currently 'looking' at (AKA coloring and checking neighbours)</param>
/// <param name="color">Color that we paint tiles. Actually an integer.</param>
/// <returns>The same TilePerim but with changed color. I chose not to modify the TilePerim within the func due to the immutability principle.</returns>
private static List <TilePerim> _TileFloodFill(IReadOnlyDictionary <int, HashSet <int> > adjMatrix,
IEnumerable <TilePerim> tilePerims, TilePerim thisTile, int color)
{
var tilePerimsClone = new List <TilePerim>(tilePerims);
var visited = new HashSet <int>();
var stack = new Stack <TilePerim>();
stack.Push(thisTile);
visited.Add(thisTile.id);
while (stack.Any())
{
TilePerim examinee = stack.Pop();
foreach (int neighbourID in adjMatrix[examinee.id].Where(x => !visited.Contains(x)))
{
TilePerim neighbour = tilePerimsClone.Find(x => x.id == neighbourID);
stack.Push(neighbour);
visited.Add(neighbourID);
}
examinee.color = color;
tilePerimsClone[tilePerimsClone.FindIndex(0, x => x.id == examinee.id)] = examinee;
}
return(tilePerimsClone);
}
