// 检查某坐标是否在多边形内部
public bool Include(Vector2 pos)
{
if (!MBR.Include(pos))
{
return(false);
}
var checker = new LineSegment((GeomPoint)pos, new GeomPoint(MBR.XMax + 10, pos.Y));
int crosses = 0;
foreach (var seg in IterSegments(true))
{
var tmp = LineSegment.CheckCross(checker, seg);
if (tmp == null) // 平行或共线
{
if (seg.Item1.Y != pos.Y)
{
continue;
}
if (seg.Item1.X < pos.X != seg.Item2.X < pos.X)
{
crosses++; // 重合线横跨待检查坐标两侧
}
}
if (0 < tmp.Item1 && tmp.Item1 < 1 && 0 <= tmp.Item2 && tmp.Item2 < 1)
{
crosses++; // Item2检查一端
}
}
return(crosses % 2 == 1); // 射线交点为奇数
}
private static MBR getMBR(IEnumerable <GeoPoint> points)
{
MBR mbr = MBR.EMPTY;
foreach (var point in points)
{
mbr.Include(point);
}
return(mbr);
}
private MBR getMBR(Trajectory trj)
{
MBR mbr = MBR.EMPTY;
int count = trj.Count;
foreach (MotionVector mv in trj)
{
mbr.Include(mv.point);
}
return(mbr);
}
private void buildIndex()
{
//insert edges into the grid
int count = trj.Count;
for (int i = 0; i < count - 1; i++)
{
MBR mbr2 = MBR.EMPTY;
mbr2.Include(trj[i].point);
mbr2.Include(trj[i + 1].point);
List <int> cids = getCells(mbr2);
foreach (int cid in cids)
{
List <int> list = null;
bool got = dict.TryGetValue(cid, out list);
if (!got)
{
list = new List <int>();
dict.Add(cid, list);
}
list.Add(i);
}
}
}
private void buildIndex()
{
//insert edges into the grid
int threadCount = 4, partCount = (int)Math.Ceiling(trjs.Count * 1.0 / threadCount);
Dictionary <int, List <long> >[] dicts = new Dictionary <int, List <long> > [threadCount];
for (int i = 0; i < threadCount; ++i)
{
dicts[i] = new Dictionary <int, List <long> >();
}
ParallelOptions op = new ParallelOptions();
op.MaxDegreeOfParallelism = threadCount;
var tmpTrjs = trjs.ToList();
int trjCount = trjs.Count;
//foreach (var item in trjs)
Parallel.For(0, threadCount, j =>
{
for (int k = j * partCount; k < Math.Min((j + 1) * partCount, trjCount); ++k)
{
var item = tmpTrjs[k];
long moid = item.Key;
var trj = item.Value;
int count = trj.Count;
var curDict = dicts[j];
for (int i = 0; i < count - 1; i++)
{
MBR mbr2 = MBR.EMPTY;
mbr2.Include(trj[i].point);
mbr2.Include(trj[i + 1].point);
List <int> cids = getCells(mbr2);
foreach (int cid in cids)
{
List <long> list = null;
bool got = curDict.TryGetValue(cid, out list);
if (!got)
{
list = new List <long>();
curDict.Add(cid, list);
}
list.Add(moid << 16 | (uint)i);
}
}
}
});
// merge
trjDict = dicts[0];
for (int i = 1; i < threadCount; ++i)
{
foreach (var item in dicts[i])
{
List <long> list = null;
if (!trjDict.TryGetValue(item.Key, out list))
{
trjDict[item.Key] = new List <long>(item.Value);
}
else
{
list.AddRange(item.Value);
}
}
}
}
