//
// If a cycle has an edge that is EXTENDED, there exist two regions, one on each side of the segment; compose the two segments.
//
// Fixed point algorithm: while there exists a cycle with an extended segment, compose.
private static void ComposeCycles(UndirectedPlanarGraph.PlanarGraph graph, List <MinimalCycle> cycles)
{
for (int cycleIndex = HasComposableCycle(graph, cycles); cycleIndex != -1; cycleIndex = HasComposableCycle(graph, cycles))
{
// Get the cycle and remove it from the list.
MinimalCycle thisCycle = cycles[cycleIndex];
cycles.RemoveAt(cycleIndex);
// Get the extended segment which is the focal segment of composition.
GeometryTutorLib.ConcreteAST.Segment extendedSeg = thisCycle.GetExtendedSegment(graph);
// Find the matching cycle that has the same Extended segment
int otherIndex = GetComposableCycleWithSegment(graph, cycles, extendedSeg);
MinimalCycle otherCycle = cycles[otherIndex];
cycles.RemoveAt(otherIndex);
// Compose the two cycles into a single cycle.
MinimalCycle composed = thisCycle.Compose(otherCycle, extendedSeg);
// Add the new, composed cycle
cycles.Add(composed);
}
}
