/// <summary>
/// 重新设置对应的Region，根据拐点的情况
/// </summary>
/// <param name="referenceSpan"></param>
/// <param name="borderDirection"></param>
/// <param name="cornerDirection"></param>
/// <returns></returns>
private int selectedRegionID(OpenHeightSpan referenceSpan,
int borderDirection,
int cornerDirection)
{
referenceSpan.getDetailedRegionMap(ref mwNeighborRegions, 0);
/*
* Initial example state:
*
* a - Known region.
* x - Null region.
* u - Unknown, not checked yet.
*
* u u u
* u a x
* u a a
*/
int antiBorderDirection = NMGenUtility.AntiDir(borderDirection);
int antiCornerDirection = NMGenUtility.AntiDir(cornerDirection);
int regionID = mwNeighborRegions[antiBorderDirection];
if (regionID == referenceSpan.regionID() ||
NULL_REGION == regionID)
{
/*
* The region away from the border is either a null region
* or the same region. So we keep the current region.
*
* u u u u u u
* a a x or x a x <-- Potentially bad, but stuck with it.
* u a a u a a
*/
return(referenceSpan.regionID());
}
int potentialRegion = regionID;
regionID = mwNeighborRegions[antiCornerDirection];
if (regionID == referenceSpan.regionID() ||
NULL_REGION == regionID)
{
/*
* The region opposite from the corner direction is
* either a null region or the same region. So we
* keep the current region.
*
* u a u u x u
* b a x or b a x
* u a a u a a
*/
return(referenceSpan.regionID());
}
int potentialCount = 0;
int currentCount = 0;
for (int i = 0; i < 8; ++i)
{
if (mwNeighborRegions[i] == referenceSpan.regionID())
{
currentCount++;
}
else if (mwNeighborRegions[i] == potentialRegion)
{
potentialCount++;
}
}
return(potentialCount < currentCount
? referenceSpan.regionID()
: potentialRegion);
}
