/// <summary>
/// Chooses a split polygon by scoring the polygon choices.
///
/// This algorithm is approximately O(N**2), so it's likely to take a while.
///
/// This method runs as a coroutine so should be run until completion.
/// </summary>
/// <param name="polygons">The polygons to choose from</param>
/// <param name="result">The resulting split polygon, along with classifications for other polygons in relation.</param>
/// <returns></returns>
private static IEnumerator ChooseSplitPolygonBestChoice(List <Polygon> polygons, ChooseSplitPolygonResult result)
{
int bestChoiceScore = int.MaxValue;
foreach (var p1 in polygons)
{
if (p1.Used)
{
continue;
}
ChooseSplitPolygonResult potentialResult = new ChooseSplitPolygonResult(p1);
potentialResult.Classify(polygons);
int frontfaces = potentialResult.Front.Count - 1; // -1 because p1 is included.
int backfaces = potentialResult.Back.Count;
int splits = potentialResult.Spanning.Count;
int score = Math.Abs(frontfaces - backfaces) + (splits * 8);
if (score < bestChoiceScore)
{
bestChoiceScore = score;
result.Assign(potentialResult);
}
yield return(null);
}
}
/// <summary>
/// Chooses a split polygon at random (non-deterministic). Also classifies
/// the rest of the polygons by whether they are in front, behind, spanning, or coincident.
///
/// This runs as a coroutine, however, this specific version only iterates once.
/// </summary>
/// <param name="polygons">The polygons to choose from</param>
/// <param name="result">The resulting polygons and polygon classification</param>
/// <returns></returns>
private static IEnumerator ChooseSplitPolygonRandom(List <Polygon> polygons, ChooseSplitPolygonResult result)
{
int index = Random.Range(0, polygons.Count);
result.Assign(new ChooseSplitPolygonResult(polygons[index]));
result.Classify(polygons);
yield return(null);
}