/// <summary>
/// Returns a singleton MazeCode instance.
/// </summary>
/// <returns></returns>
public static MazeCode Instance(int version)
{
if (instance[version] == null)
{
instance[version] = new MazeCode(version);
}
return(instance[version]);
}
/// <summary>
/// Constructor.
/// Create a maze whose parameters are encoded in the given code (see property Code).
/// </summary>
/// <param name="code">a string of seven letters (case is ignored)</param>
public Maze(string code)
{
int version = MazeCode.GetCodeVersion(code);
this.dimensionsObj = MazeDimensions.Instance(version);
this.codeObj = MazeCode.Instance(version);
codeObj.Decode(code
, out this.seed
, out this.xSize, out this.ySize
);
this.random = RandomFactory.CreateRandom(seed);
}
/// <summary>
/// Constructor.
/// Create a maze with the given dimensions.
/// </summary>
/// <param name="xSize"></param>
/// <param name="ySize"></param>
/// <param name="version"></param>
/// <param name="seed"></param>
internal Maze(int xSize, int ySize, int version, int seed)
{
this.dimensionsObj = MazeDimensions.Instance(version);
this.codeObj = MazeCode.Instance(version);
this.xSize = Math.Max(dimensionsObj.MinSize, Math.Min(dimensionsObj.MaxXSize, xSize));
this.ySize = Math.Max(dimensionsObj.MinSize, Math.Min(dimensionsObj.MaxYSize, ySize));
// Get an initial random seed and use that to create the Random.
if (seed < 0)
{
Random r = RandomFactory.CreateRandom();
this.seed = r.Next(codeObj.SeedLimit);
}
else
{
this.seed = seed;
}
this.random = RandomFactory.CreateRandom(this.seed);
}
/// <summary>
/// Calculate maximum x and y dimensions, based on the desired Maze.Code length.
/// </summary>
protected void CalculateDimensions(out int xRange, out int yRange)
{
MazeCode codeObj = MazeCode.Instance(codeVersion);
double codeLimit = Math.Pow(codeObj.CodeDigitRange, codeObj.CodeLength);
if (codeLimit > long.MaxValue)
{
throw new Exception("Maze.Code is too large to be represented as a 64 bit integer");
}
codeLimit /= codeObj.SeedLimit;
// (MaxXSize - MinSize + 1)
// (MaxYSize - MinSize + 1)
if (codeVersion == 0)
{
codeLimit /= (int)WallPosition.WP_NUM;
codeLimit /= (MaxBorderDistance + 1);
codeLimit /= (MaxBorderDistance + 1);
// (MaxXSize + 1)
// (MaxXSize + 1)
}
double x;
if (codeVersion == 0)
{
/* We want to find the greatest integer MaxXSize and MaxYSize with the limitation:
* (x-m) * (y-m) * x * x < c
* with:
* x = MaxXSize + 1
* y = MaxYSize + 1 = MaxXSize / XYRatio + 1
* m = MinSize
* c = codeLimit
* r = XYRatio
*
* This is approximately equivalent to:
* x*x*x*x < c*r
* or
* x = (c*r)^^(1/4)
* With m>0, that x is even too small.
*/
x = Math.Truncate(Math.Pow(codeLimit * XYRatio, 0.25));
while ((x - MinSize) * (x / XYRatio - MinSize) * (x) * (x) < codeLimit)
{
x = x + 1;
}
}
else
{
/* We want to find the greatest integer MaxXSize and MaxYSize with the limitation:
* (x-m) * (y-m) < c
* with:
* x = MaxXSize + 1
* y = MaxYSize + 1 = MaxXSize / XYRatio + 1
* m = MinSize
* c = codeLimit
* r = XYRatio
*
* This is approximately equivalent to:
* x*x*x*x < c*r
* or
* x = (c*r)^^(1/2)
* With m>0, that x is even too small.
*/
x = Math.Truncate(Math.Pow(codeLimit * XYRatio, 0.5));
while ((x - MinSize) * (x / XYRatio - MinSize) < codeLimit)
{
x = x + 1;
}
}
/* Now, x is 1 greater than acceptable, i.e.
* x-1 = MaxXSize + 1 = MinSize + xRange + 1
* MinSize + yRange = MaxYSize = MaxXSize / XYRatio
*/
xRange = (int)(x - MinSize - 2);
yRange = (int)(MaxXSize / XYRatio - MinSize); // Note: MaxXSize is valid after xRange has been assigned
}