public CellItem(CellItem cellItem, double minDist)
{
this.cellId = cellItem.cellId;
this.minDist = minDist;
}
public static List<CabMetaData> RangeQuery(Grid grid, CabMetaData queryPoint, double radious, List<CabMetaData> cabLine)
{
List<CabMetaData> result = new List<CabMetaData>();//结果集
//获取中心点所在单元格，并计算向四个方向最多扩展的次数
int centerCell = LocateCell(queryPoint);
int left = centerCell % gridTier;
int right = gridTier - (centerCell % gridTier) - 1;
int up = centerCell / gridTier;
int down = gridTier - (centerCell / gridTier) - 1;
Queue<CellItem> candidateCells=new Queue<CellItem>();
bool[] validArray = new bool[gridTier * gridTier];//对应网格是否已入队列，已入为true
for (int i = 0;i!=gridTier*gridTier ;i++ )
{
validArray[i] = false;
}
candidateCells.Enqueue(new CellItem(centerCell,0.0));
validArray[centerCell] = true;
int times = 1;//扩散次数
while (candidateCells.Count > 0)
{
CellItem nextCell = candidateCells.Dequeue();
if (nextCell.minDist > radious)//网格完全在圆外面
{
break;
}
double cellMaxDist = GetMaxDist(queryPoint, nextCell.cellId);
List<CabMetaData> pointsOfCell = grid.cellList[nextCell.cellId].GetAllPoints();
if (cellMaxDist <= radious)//网格完全被圆包含
{
foreach (CabMetaData point in pointsOfCell)
{
result.Add(point);
}
}
else//网格与圆部分相交
{
//检查网格每个点是否落于圆中
foreach (CabMetaData point in pointsOfCell)
{
if (Program.GetDistance(queryPoint.Latitude, queryPoint.Longitude, point.Latitude, point.Longitude) <= radious)
{
result.Add(point);
}
}
}
//扩散邻居网络
if (candidateCells.Count == 0)
{
if (times <= up)//未上溢出
{
int upMidCell = centerCell - times * gridTier;
if (!validArray[upMidCell])
{
candidateCells.Enqueue(new CellItem(upMidCell,GetMinDist(queryPoint,upMidCell)));
}
for (int i = 1; i <= (times < left ? times : left); i++)
{
int nextCellInt = upMidCell - i;
if (!validArray[nextCellInt])
{
candidateCells.Enqueue(new CellItem(nextCellInt, GetMinDist(queryPoint, nextCellInt)));
}
}
for (int i = 1; i <= (times < right ? times : right); i++)
{
int nextCellInt = upMidCell + i;
if (!validArray[nextCellInt])
{
candidateCells.Enqueue(new CellItem(nextCellInt,GetMinDist(queryPoint,nextCellInt)));
}
}
}
if (times <= down)//未下溢出
{
int downMidCell = centerCell + times * gridTier;
if (!validArray[downMidCell])
{
candidateCells.Enqueue(new CellItem(downMidCell,GetMinDist(queryPoint,downMidCell)));
}
for (int i = 1; i <= (times < left ? times : left); i++)
{
int nextCellInt = downMidCell - i;
if (!validArray[nextCellInt])
{
candidateCells.Enqueue(new CellItem(nextCellInt, GetMinDist(queryPoint, nextCellInt)));
}
}
for (int i = 1; i <= (times < right ? times : right); i++)
{
int nextCellInt = downMidCell + i;
if (!validArray[nextCellInt])
{
candidateCells.Enqueue(new CellItem(nextCellInt, GetMinDist(queryPoint, nextCellInt)));
}
}
}
if (times <= left)//未左溢出
{
int leftMidCell = centerCell - times;
if (!validArray[leftMidCell])
{
candidateCells.Enqueue(new CellItem(leftMidCell, GetMinDist(queryPoint, leftMidCell)));
}
for (int i = 1; i <= (times<up?times:up); i++)
{
int nextCellInt = leftMidCell - gridTier * i;
if (!validArray[nextCellInt])
{
candidateCells.Enqueue(new CellItem(nextCell, GetMinDist(queryPoint, nextCellInt)));
}
}
for (int i = 1; i <= (times<down?times:down); ++i)
{
int nextCellInt = leftMidCell +gridTier * i;
if (!validArray[nextCellInt])
{
candidateCells.Enqueue(new CellItem(nextCellInt, GetMinDist(queryPoint, nextCellInt)));
}
}
}
if (times <= right) //未右溢出
{
int rightMidCell = centerCell + times;
if (!validArray[rightMidCell])
{
candidateCells.Enqueue(new CellItem(rightMidCell, GetMinDist(queryPoint, rightMidCell)));
}
for (int i = 1; i <= (times<up?times:up); ++i)
{
int nextCellInt = rightMidCell - gridTier * i;
if (!validArray[nextCellInt])
{
candidateCells.Enqueue(new CellItem(nextCell, GetMinDist(queryPoint, nextCellInt)));
}
}
for (int i = 1; i <= (times<down?times:down); ++i)
{
int nextCellInt = rightMidCell + gridTier * i;
if (!validArray[nextCellInt])
{
candidateCells.Enqueue(new CellItem(nextCellInt, GetMinDist(queryPoint, nextCellInt)));
}
}
}
times++;
}
}
return result;
}