/// <summary>
/// Create a new Cave Generator
/// </summary>
/// <param name="input">The input map, usually white noise</param>
/// <param name="threshold">Input values below this threshold will be treated as zero</param>
/// <param name="iterations">How many times to iterate the automata, higher values give smoother caves, but are slow</param>
/// <param name="searchRadius">Neighbour search radius</param>
/// <param name="birthRule"></param>
/// <param name="deathRule"></param>
public CaveGenerator(ValueMap input, float threshold, int iterations = 3, int searchRadius = 1, int birthRule = 2, int deathRule = 3)
{
this.threshold = threshold;
this.iterations = iterations;
this.searchRadius = searchRadius;
this.birthRule = birthRule;
this.deathRule = deathRule;
this.input = input;
size = new Vector2Int(input.Width, input.Height);
map = ValueMap.CreateInstance(size);
buffer = ValueMap.CreateInstance(size);
}
public override object GetValue(NodePort port)
{
var graph = (Terra2DGraph)this.graph;
if (graph.isComputing)
{
try
{
output = ValueMap.CreateInstance(graph.size.x, graph.size.y, gradient, vertical);
return(output);
}
catch (System.Exception e)
{
graph.isComputing = false;
throw e;
}
}
return(null);
}
public ValueMap Generate()
{
// initialize
maze = ValueMap.CreateInstance(size.x, size.y);
random = new System.Random(seed.GetHashCode());
List <Vector2Int> activeCells = new List <Vector2Int>();
// add the start cell to the active list
activeCells.Add(start);
maze[start.x, start.y] = 1;
// while active list is not empty
while (activeCells.Count > 0)
{
// select cell from active list
// randomly selected based on waviness
// higher waviness produces long winding passages with fewer dead ends, and vice versa
int cellIndex = random.NextDouble() > waviness?random.Next(activeCells.Count) : activeCells.Count - 1;
var cell = activeCells[cellIndex];
// get untraversed neighbours of selected cell
var neighbours = GetNeighbours(cell.x, cell.y);
if (neighbours.Count > 0)
{
// randomly select a neighbour and connect it to the selected cell
var neighbour = neighbours[random.Next(neighbours.Count)];
maze.ConnectCells(cell, neighbour, 1);
// add that neighbour to the active list
activeCells.Add(neighbour);
}
else
{
// if no traversable neighbours, remove cell from active list
activeCells.Remove(cell);
}
}
return(maze);
}
public static ValueMap CellNoise(int seed, Vector2Int size, Vector2 offset, FastNoise.CellularDistanceFunction distanceFunction, FastNoise.CellularReturnType returnType, float jitter = 0.45f, float frequency = 0.02f)
{
var noise = new FastNoise(seed);
noise.SetCellularDistanceFunction(distanceFunction);
noise.SetCellularReturnType(returnType);
noise.SetCellularJitter(jitter);
noise.SetFrequency(frequency);
ValueMap output = ValueMap.CreateInstance(size);
for (int x = 0; x < size.x; x++)
{
for (int y = 0; y < size.y; y++)
{
output[x, y] = noise.GetCellular(offset.x + x, offset.y + y);
}
}
return(output);
}