//Rectangle
public bool Collide(float left, float top, float right, float bottom)
{
//Need to check every tile that this rect contains for collisions.
var startX = (int)(left / CellWidth);
var startY = (int)(top / CellHeight);
var endX = (int)(right / CellWidth);
var endY = (int)(bottom / CellHeight);
var key = new Point(0, 0);
for (int x = startX; x <= endX; x++)
{
for (int y = startY; y <= endY; y++)
{
key.X = x;
key.Y = y;
if (grid.Contains(key))
{
return(true);
}
}
}
return(false);
}
private static InfiniteGrid <TileWithOrientation>?Search(List <Tile> tiles,
InfiniteGrid <TileWithOrientation> grid, int size)
{
if (grid.Width > size || grid.Height > size)
{
return(null);
}
if (grid.Width == size && grid.Height == size && grid.Positions().Count() == size * size)
{
return(grid);
}
var openPositions = grid.Positions()
.SelectMany(p => p.Orthogonal())
.Where(p => !grid.Contains(p));
foreach (var position in openPositions)
{
var constraints = new List <FacingAndValue> ();
foreach (var facing in new[] { Vector.North, Vector.East, Vector.South, Vector.West }.Zip(new[] { 0, 1, 2, 3 }))
{
if (grid.TryPosition(position + facing.First, out var borderingCell))
{
var borderingCellsFacing = facing.Second switch
{
0 => 2,
1 => 3,
2 => 0,
3 => 1,
_ => throw new ApplicationException()
};
constraints.Add(new FacingAndValue(facing: facing.Second, borderingCell.Borders[borderingCellsFacing]));
}
}
var validTiles = new List <TileWithOrientation>();
foreach (var tile in tiles)
{
var c = constraints.First();
if (!tile.Orientations.TryGetValue(c, out var proposed))
{
continue;
}
foreach (var constraint in constraints.Skip(1))
{
if (!tile.Orientations.TryGetValue(constraint, out var proposed2) ||
proposed != proposed2)
{
proposed = null;
break;
}
}
if (proposed == null)
{
break;
}
validTiles.Add(proposed);
}
foreach (var tile in validTiles)
{
var gridCopy = grid.Clone();
gridCopy.Add(position, tile);
var tilesCopy = tiles.ToList();
tilesCopy.Remove(tile.Tile);
var newGrid = Search(tilesCopy, gridCopy, size);
if (newGrid != null)
{
return(newGrid);
}
}
}
return(null);
}