/// <summary>
/// Returns the largest subset of the template shape whose squares are all connected to each other.
/// </summary>
/// <param name="template"></param>
/// <param name="isReserved">defines the maze's reserved areas</param>
/// <returns></returns>
public static OutlineShape ConnectedSubset(OutlineShape template, InsideShapeDelegate isReserved)
{
ExplicitOutlineShape result = new ExplicitOutlineShape(template, isReserved);
#region Scan the shape for connected areas.
byte subsetId = 1;
int largestAreaSize = 0;
byte largestAreaId = 0;
for (int x = 0; x < result.XSize; x++)
{
for (int y = 0; y < result.YSize; y++)
{
if (result.squares[x, y] == 1 && subsetId < byte.MaxValue)
{
int areaSize = result.FillSubset(x, y, ++subsetId);
if (areaSize > largestAreaSize)
{
largestAreaSize = areaSize;
largestAreaId = subsetId;
}
}
}
}
#endregion
#region Leave only the largest subset, eliminate all others.
for (int x = 0; x < result.XSize; x++)
{
for (int y = 0; y < result.YSize; y++)
{
result.SetValue(x, y, (result.squares[x, y] == largestAreaId));
}
}
#endregion
return(result);
}
/// <summary>
/// Returns the template shape, augmented by all totally enclosed areas.
/// </summary>
/// <param name="template"></param>
/// <param name="isReserved">defines the maze's reserved areas</param>
/// <returns></returns>
public static OutlineShape Closure(OutlineShape template, InsideShapeDelegate isReserved)
{
ExplicitOutlineShape result = new ExplicitOutlineShape(template.Inverse());
#region Scan and mark the reserved areas.
if (isReserved != null)
{
byte reservedId = 3;
for (int x = 0; x < result.XSize; x++)
{
for (int y = 0; y < result.YSize; y++)
{
if (isReserved(x, y))
{
result.squares[x, y] = reservedId;
}
}
}
}
#endregion
#region Scan all outside areas.
byte outsideId = 2;
int x0 = 0, x1 = result.XSize - 1, y0 = 0, y1 = result.YSize - 1;
for (int x = 0; x < result.XSize; x++)
{
if (result.squares[x, y0] == 1)
{
result.FillSubset(x, y0, outsideId);
}
if (result.squares[x, y1] == 1)
{
result.FillSubset(x, y1, outsideId);
}
}
for (int y = 0; y < result.YSize; y++)
{
if (result.squares[x0, y] == 1)
{
result.FillSubset(x0, y, outsideId);
}
if (result.squares[x1, y] == 1)
{
result.FillSubset(x1, y, outsideId);
}
}
#endregion
#region Add the areas which were not reached.
for (int x = 0; x < result.XSize; x++)
{
for (int y = 0; y < result.YSize; y++)
{
// 0: square is part of the template (not part of its inverse)
// 1: square is not part of the template, but was not reached
result.SetValue(x, y, (result.squares[x, y] <= 1));
}
}
#endregion
return(result);
}