/// <summary>
/// </summary>
/// <param name="startSpan"></param>
/// <param name="borderDirection"></param>
/// <param name="newRegionID"></param>
private void partialFloodRegion(OpenHeightSpan startSpan,
int borderDirection,
int newRegionID)
{
int antiBorderDirection = NMGenUtility.AntiDir(borderDirection);
int regionID = startSpan.regionID();
startSpan.setRegionID(newRegionID);
startSpan.setDistanceToRegionCore(0); //???所以这个值 没啥卵用啊，一直都是0的
mwOpenSpans.Push(startSpan);
mwBorderDistance.Push(0);
while (mwOpenSpans.Count > 0)
{
OpenHeightSpan span = mwOpenSpans.Pop();
int distance = mwBorderDistance.Pop();
for (int i = 0; i < 4; ++i)
{
OpenHeightSpan nSpan = span.getNeighbor(i);
if (null == nSpan ||
nSpan.regionID() != regionID)
{
continue;
}
int nDistance = distance;
if (i == borderDirection) //null region所在的方向
{
//这里是不是应该小于等于0呢？
// 以这个距离Border为0作为边界，将大于0那一侧的Span全部变成
// 新的Region。然后小于等于0那一侧的作为旧的Region保留下来。
if (0 == distance)
{
continue;
}
nDistance--;
}
else if (i == antiBorderDirection)
{
nDistance++;
}
//注意上面的if-else，如果都不是这两个方向的Span
//会直接被重新设置为新的Region
nSpan.setRegionID(newRegionID);
nSpan.setDistanceToRegionCore(0);
mwOpenSpans.Push(nSpan);
mwBorderDistance.Push(nDistance);
}
}
}
/// <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);
}
public void apply(OpenHeightfield field)
{
if (null == field)
{
Logger.LogError("[CLeanNullRegionBorders][apply]field null");
return;
}
int nextRegionID = field.regionCount();
OpenHeightfield.OpenHeightFieldIterator iter = field.GetEnumerator();
while (iter.MoveNext())
{
OpenHeightSpan span = iter.Current;
if (span.flags != 0)
{
continue;
}
span.flags = 1;
OpenHeightSpan workingSpan = null;
int edgeDirection = -1;
if (NULL_REGION == span.regionID())
{
//找到Border Span第一个非空的邻居
edgeDirection = getNonNullBorderDrection(span);
if (-1 == edgeDirection)
{
continue;
}
//起点Span为有所属Region的Span
//而行走方向为 null Region所在的方向
workingSpan = span.getNeighbor(edgeDirection);
//转180度
edgeDirection = NMGenUtility.AntiDir(edgeDirection);
}
else if (!mUseOnlyNullSpans)
{
//起点Span为 null Region的Span
//而行走方向即为有所属 Region 的 Span
edgeDirection = getNullBorderDrection(span);
if (-1 == edgeDirection)
{
continue;
}
workingSpan = span;
}
else
{
continue;
}
//上面两个分支都会保证workingSpan是有所属Region的
//而Dir 即是 Region 为 Null Region的Dir
bool isEncompassedNullRegion = processNullRegion(workingSpan, edgeDirection);
if (isEncompassedNullRegion) //确定以这个Span为起点的Region，是一个单一Region，并且内含了一个Null Region
{
//如果是完全包含了不可走的NullRegion ，就将这个Region分割成两个Region
partialFloodRegion(workingSpan, edgeDirection, nextRegionID);
nextRegionID++;
}
}
field.setRegionCount(nextRegionID);
iter.Reset();
while (iter.MoveNext())
{
iter.Current.flags = 0;
}
}