static TwoWayLookup CreateLookupTable(int capacity, byte[,] configurations)
{
var lookupTable = new TwoWayLookup(capacity);
int length = configurations.GetLength(0);
int width = configurations.GetLength(1);
for (int y = 0; y < width; y++)
{
for (int x = 0; x < length; x++)
{
byte[] outlineData = outlineTable[configurations[x, y]];
for (int i = 0; i < outlineData.Length; i += 2)
{
var a = new XLocalPosition(x, y, outlineData[i]);
var b = new XLocalPosition(x, y, outlineData[i + 1]);
lookupTable.AddPair(a, b);
}
}
}
return(lookupTable);
}
public static List <Vector3[]> Generate(OIGrid grid, Vector3 basePos, int squareSize)
{
byte[,] configurations = XMarchingSquares.ComputeConfigurations(grid);
int numOutlineEdges = CountOutlineEdges(configurations);
TwoWayLookup outlineLookup = CreateLookupTable(numOutlineEdges, configurations);
var outlines = new List <Vector3[]>();
var visited = new HashSet <XLocalPosition>();
foreach (var pair in outlineLookup.EnumerateBackwards())
{
if (!visited.Contains(pair.Key))
{
XLocalPosition start = pair.Key;
XLocalPosition next = pair.Value;
var outline = new List <XLocalPosition>();
AddToOutline(outline, start, visited);
AddToOutline(outline, next, visited);
// first do a backward pass until looping or running out of connected outline edges
while (start != next && outlineLookup.TryGetBackwardValue(next, out next))
{
AddToOutline(outline, next, visited);
}
outline.Reverse();
// if no loop, then do a forward pass from the starting point
if (start != next)
{
next = start;
while (outlineLookup.TryGetForwardValue(next, out next))
{
AddToOutline(outline, next, visited);
}
}
outlines.Add(ToGlobalPositions(outline, squareSize, basePos));
}
}
return(outlines);
}
static void AddToOutline(List <XLocalPosition> outline, XLocalPosition item, HashSet <XLocalPosition> visited)
{
visited.Add(item);
outline.Add(item);
}
public bool TryGetBackwardValue(XLocalPosition key, out XLocalPosition value)
{
return(backwardLookup.TryGetValue(key, out value));
}
public void AddPair(XLocalPosition start, XLocalPosition end)
{
forwardLookup[start] = end;
backwardLookup[end] = start;
}
