private static Partition Merge(Partition leftPartition, Partition rightPartition)
{
QuadEdge left = leftPartition.Left; //ldo
QuadEdge right = rightPartition.Right; //rdo
LowestCommonTangent(leftPartition, rightPartition, out QuadEdge lowLeft, out QuadEdge lowRight); //ldi, rdi
QuadEdge edgeBase = QuadEdge.ConnectLeft(lowRight.Inverse, lowLeft);
QuadEdge lcand = edgeBase.RightPrevious;
QuadEdge rcand = edgeBase.OriginPrevious;
if (edgeBase.Origin == right.Origin)
{
right = edgeBase;
}
if (edgeBase.Destination == left.Origin)
{
left = edgeBase.Inverse;
}
while (true)
{
QuadEdge temp = lcand.OriginNext;
if (Point.IsCounterClockWise(edgeBase.Origin, temp.Destination, edgeBase.Destination))
{
while (edgeBase.Origin.InCircle(lcand.Destination, temp.Destination, lcand.Origin))
{
lcand.Delete();
lcand = temp;
temp = lcand.OriginNext;
}
}
temp = rcand.OriginPrevious;
if (Point.IsCounterClockWise(edgeBase.Origin, temp.Destination, edgeBase.Destination))
{
while (edgeBase.Destination.InCircle(temp.Destination, rcand.Destination, rcand.Origin))
{
rcand.Delete();
rcand = temp;
temp = rcand.OriginPrevious;
}
}
bool leftValid = Point.IsCounterClockWise(edgeBase.Origin, lcand.Destination, edgeBase.Destination);
bool rightValid = Point.IsCounterClockWise(edgeBase.Origin, rcand.Destination, edgeBase.Destination);
if (!leftValid && !rightValid)
{
break;
}
if (!leftValid ||
rightValid && rcand.Destination.InCircle(lcand.Destination, lcand.Origin, rcand.Origin))
{
edgeBase = QuadEdge.ConnectLeft(rcand, edgeBase.Inverse);
rcand = edgeBase.Inverse.LeftNext;
}
else
{
edgeBase = QuadEdge.ConnectRight(lcand, edgeBase).Inverse;
lcand = edgeBase.RightPrevious;
}
}
return(new Partition
{
Left = left,
Right = right
});
}
