isRing static method
Tests whether a {@link CoordinateSequence} forms a valid {@link LinearRing}, by checking the sequence length and closure (whether the first and last points are identical in 2D). Self-intersection is not checked.
@param seq the sequence to test @return true if the sequence is a ring @see LinearRing
Implementation
static bool isRing(CoordinateSequence seq) {
int n = seq.size();
if (n == 0) return true;
// too few points
if (n <= 3) return false;
// test if closed
return seq.getOrdinate(0, CoordinateSequence.X) ==
seq.getOrdinate(n - 1, CoordinateSequence.X) &&
seq.getOrdinate(0, CoordinateSequence.Y) ==
seq.getOrdinate(n - 1, CoordinateSequence.Y);
}