Helper function to be used as comparator for the SplayScanLine.
Compute approximate intersection point of two edges in floating point coordinates.
Compute intersection of edges in integer coordinates.
For edges that are parallel to the x or y axis the intersection can be computed exactly.
For others it will be rounded.
Compute the intersection of edges with rational coordinates.
In rational coordinates intersections can be computed exactly.
Find all intersecting segments and subdivide them such that the set of resulting segments contains
no intersecting segments anymore.
The resulting events are sorted by their coordinates.