/// <summary>
/// 计算下载任务列表
/// </summary>
public void CalculateQuest()
{
// 先按多边形分组，一组点可能组成多个多边形
var points = m_points;
//while (points.Any())
//{
// var index = points.ToList().LastIndexOf(points.First());
// if (index == 0)
// {
// if (points.Any())
// {
// File.AppendAllLines("points.txt", points.Select(o=>$"{o.X},{o.Y}"));
// }
// break;
// }
// var region = new MercatorRegion(points.Take(index + 1));
// m_mercatorRegions.Add(region);
// points = points.Skip(index + 1).ToList();
//}
if (!m_mercatorRegions.Any())
{
throw new ArgumentException("无法构建成多边形，请检查点是否闭合");
}
// 只计算最大层，其余层通过缩小计算得出
var tileRegionList = m_mercatorRegions.Select(o => o.GetTileRegion(MaxZoom));
var segments = tileRegionList.Aggregate(Enumerable.Empty <TileSegment>(), (current, region) => current.Concat(region.GetTileSegments())).ToList();
var minY = (long)Math.Floor(segments.Min(o => o.MinY));
var maxY = (long)Math.Floor(segments.Max(o => o.MaxY));
// 每个Y值计算一次交点
var taskGroup = new MapZoom(MaxZoom);
for (var i = minY; i <= maxY; i++)
{
var y = i;
var matchSegments = segments.Where(o => (o.MaxY >= y) && (o.MinY <= y));
var intersectList = new List <TilePoint>();
foreach (var s in matchSegments)
{
intersectList.Add(s.IntersectY(y));
}
// 分解任务
intersectList = intersectList.OrderBy(o => o.X).ToList();
for (var index = 0; index < intersectList.Count; index += 2)
{
var x1 = (long)Math.Floor(intersectList[index].X);
var x2 = (long)Math.Floor(intersectList[index + 1].X);
var task = new MapLine
{
StartX = x1,
EndX = x2,
Y = y,
Zoom = MaxZoom
};
taskGroup.AddTask(task);
}
}
// 将线段两点加入任务组
foreach (var s in segments)
{
taskGroup.AddTask(GetTaskFromTilePoint(s.Point1, MaxZoom));
taskGroup.AddTask(GetTaskFromTilePoint(s.Point2, MaxZoom));
}
// 将线段所有x轴点加入任务组
var minX = (long)Math.Floor(segments.Min(o => o.MinX));
var maxX = (long)Math.Floor(segments.Max(o => o.MaxX));
for (var i = minX; i <= maxX; i++)
{
var x = i;
var matchSegments = segments.Where(o => (o.MaxX >= x) && (o.MinX <= x));
foreach (var s in matchSegments)
{
taskGroup.AddTask(GetTaskFromTilePoint(s.IntersectX(x), MaxZoom));
}
}
// 整合任务组
m_zoomTasks.Add(taskGroup);
var tg = taskGroup;
for (var index = MaxZoom - 1; index >= MinZoom; index--)
{
tg = tg.ScaleTo(index);
m_zoomTasks.Add(tg);
}
}
