/**
* Creates an edge index over the vertices, which by itself takes no time.
* Then the expected number of queries is used to determine whether brute
* force lookups are likely to be slower than really creating an index, and if
* so, we do so. Finally an iterator is returned that can be used to perform
* edge lookups.
*/
private S2EdgeIndex.DataEdgeIterator GetEdgeIterator(int expectedQueries)
{
if (_index == null)
{
_index = new AnonS2EdgeIndex(this);
}
_index.PredictAdditionalCalls(expectedQueries);
return(new S2EdgeIndex.DataEdgeIterator(_index));
}
/**
* Copy constructor.
*/
public S2Loop(S2Loop src)
{
_numVertices = src._numVertices;
_vertices = (S2Point[])src._vertices.Clone();
_vertexToIndex = src._vertexToIndex;
_index = src._index;
_firstLogicalVertex = src._firstLogicalVertex;
_bound = src.RectBound;
_originInside = src._originInside;
_depth = src._depth;
}
/**
* Like the constructor above, but assumes that the cell's bounding rectangle
* has been precomputed.
*
* @param cell
* @param bound
*/
public S2Loop(S2Cell cell, S2LatLngRect bound)
{
_bound = bound;
_numVertices = 4;
_vertices = new S2Point[_numVertices];
_vertexToIndex = null;
_index = null;
_depth = 0;
for (var i = 0; i < 4; ++i)
{
_vertices[i] = cell.GetVertex(i);
}
InitOrigin();
InitFirstLogicalVertex();
}
/**
* Reverse the order of the loop vertices, effectively complementing the
* region represented by the loop.
*/
public void Invert()
{
var last = NumVertices - 1;
for (var i = (last - 1) / 2; i >= 0; --i)
{
var t = _vertices[i];
_vertices[i] = _vertices[last - i];
_vertices[last - i] = t;
}
_vertexToIndex = null;
_index = null;
_originInside ^= true;
if (_bound.Lat.Lo > -S2.PiOver2 && _bound.Lat.Hi < S2.PiOver2)
{
// The complement of this loop contains both poles.
_bound = S2LatLngRect.Full;
}
else
{
InitBound();
}
InitFirstLogicalVertex();
}
public DataEdgeIterator(S2EdgeIndex edgeIndex)
{
this._edgeIndex = edgeIndex;
_candidates = new List <int>();
}