/// <summary>
/// 相对原点的多边形边界
/// </summary>
/// <param name="source"></param>
/// <param name="vertex"></param>
/// <param name="mintheta"></param>
/// <param name="maxtheta"></param>
/// <param name="distance"></param>
/// <returns></returns>
public static bool getBoundPointIndex(Point source, List <Point> vertex, ref TriangleBound tb)
{
bool isEdge;
int startIndex = 0;
//原点是否在多边形内部
if (GeometricUtilities.PointInPolygon(vertex.ToArray(), source, out isEdge, ref startIndex))
{
return(false);
}
tb.maxIndex = -1;
tb.maxTheta = -1;
tb.minIndex = int.MaxValue - 500;
tb.minTheta = 1000;
tb.totalVertex = vertex.Count;
double theta;
Dictionary <int, Polar> tmp = new Dictionary <int, Polar>();
int cnt = vertex.Count;
Polar p;
//求相对原点的极坐标，根据theta角判断边界
for (int i = 0; i < cnt; i++)
{
p = GeometricUtilities.getPolarCoord(source, vertex[i]);
theta = p.theta;
tmp.Add(i, p);
if (theta < tb.minTheta)
{
tb.minIndex = i;
tb.minTheta = theta;
}
if (theta > tb.maxTheta)
{
tb.maxIndex = i;
tb.maxTheta = theta;
}
}
//说明多边形与x轴相交
if (tb.maxTheta - tb.minTheta > Math.PI)
{
double th;
tb.maxIndex = -1;
tb.maxTheta = -1;
tb.minIndex = int.MaxValue - 500;
tb.minTheta = 1000;
foreach (var kv in tmp)
{
th = kv.Value.theta;
if (th < Math.PI)
{
if (th > tb.maxTheta)
{
tb.maxIndex = kv.Key;
tb.maxTheta = th;
}
}
else if (th < tb.minTheta)
{
tb.minIndex = kv.Key;
tb.minTheta = th;
}
}
}
tb.stob = tmp[tb.minIndex].r > tmp[(tb.minIndex + 1) % cnt].r;
return(true);
}
/// <summary>
/// 获取一个建筑物棱边绕射点
/// </summary>
/// <param name="baseHeight"></param>
/// <param name="tb"></param>
/// <param name="gridLength"></param>
/// <returns></returns>
private static List <Point> getOneBuildingEdgePointsByShelter(double baseHeight, TriangleBound tb, double gridLength)
{
List <Point> ret = new List <Point>();
Point t;
List <Point> v = buildingVertex[tb.buildingid];
//获取垂直棱边
for (int i = tb.minIndex, e = (tb.maxIndex + 1) % tb.totalVertex; i != e; i = (i + 1) % tb.totalVertex)
{
double d = gridLength / 2;
for (double j = tb.baseHeight + d; j < tb.height - d; j += gridLength)
{
t = new Point(v[i]);
t.Z = j;
ret.Add(t);
}
}
//获取水平棱边
//for (int i = tb.minIndex, e = (tb.maxIndex + 1) % tb.totalVertex; i != e; i = (i + 1) % tb.totalVertex)
//{
// List<Point> tmp = VerticalPlaneGrid.GetHEdgePoints(v[i], v[(i + 1) % tb.totalVertex], gridLength, tb.height);
// ret.AddRange(tmp);
//}
if (baseHeight > tb.height)
{
for (int i = 0; i < tb.totalVertex - 1; i++)
{
List <Point> tmp = VerticalPlaneGrid.GetHEdgePoints(v[i], v[(i + 1) % tb.totalVertex], gridLength, tb.height);
ret.AddRange(tmp);
}
}
else
{
int i = tb.minIndex, end = (tb.maxIndex + 1) % tb.totalVertex;
int j = (i - 1 + tb.totalVertex) % tb.totalVertex;
for (; i != end; j = i, i = (i + 1) % tb.totalVertex)
{
List <Point> tmp = VerticalPlaneGrid.GetHEdgePoints(v[i], v[j], gridLength, tb.height);
ret.AddRange(tmp);
}
}
return(ret);
}
/// <summary>
/// 求比基准高度高的建筑物遮挡距离和角度范围
/// </summary>
/// <param name="source"></param>
/// <param name="buildingids"></param>
/// <param name="baseHeight"></param>
/// <returns></returns>
/// /// <summary>
/// 建筑物遮挡关系（极坐标系）
/// </summary>
/*
* public struct TriangleBound
* {
* //建筑物id
* public int buildingid;
* public int totalVertex;
* //角度最小的边界点的索引
* public int minIndex;
* public double minTheta;
* //角度最大的边界点的索引
* public int maxIndex;
* public double maxTheta;
* //离原点较近的边是否是从minIndex到maxIndex
* public bool stob;
* //原点与建筑物的距离（近似值）
* public double distance;
* //违背遮挡高度
* public double baseHeight;
* //建筑物高度
* public double height;
* }
*/
public static List <TriangleBound> getShelterDisAndAngle(Point source, List <int> buildingids, double baseHeight)
{
Dictionary <int, TriangleBound> bdis = new Dictionary <int, TriangleBound>();
TriangleBound tb = new TriangleBound();
double height, sz = baseHeight, altitude;
int bid;
for (int i = 0, cnt = buildingids.Count; i < cnt; i++)
{
bid = buildingids[i];
height = buildingHeight[bid];
altitude = buildingAltitude[bid]; // 地形
if (height > sz)
{
tb = new TriangleBound();
tb.height = height;
tb.baseHeight = altitude; // 地形
tb.distance = GeometricUtilities.GetDistanceOf2DPoints(source, buildingCenter[bid]);
bdis[bid] = tb;
}
}
List <KeyValuePair <int, TriangleBound> > bdisOrder = bdis.OrderBy(c => c.Value.distance).ToList();
List <TriangleBound> ret = new List <TriangleBound>();
foreach (var kv in bdisOrder)
{
bid = kv.Key;
tb = bdis[bid];
// 得到每个建筑物相对于原点的最小、最大角度
if (getBoundPointIndex(source, buildingVertex[bid], ref tb))
{
tb.buildingid = bid;
ret.Add(tb);
}
}
//去掉一些遮挡的
double min1, max1, min2, max2;
for (int i = ret.Count - 1; i > 0; i--)
{
for (int j = i - 1; j >= 0; j--)
{
min1 = ret[j].minTheta;
max1 = ret[j].maxTheta;
min2 = ret[i].minTheta;
max2 = ret[i].maxTheta;
// j比i范围广，且在i前面
if (max2 < max1 && min2 > min1)
{
if (ret[j].height >= ret[i].height) // j完全挡住了i
{
ret.RemoveAt(i);
break;
}
else if (ret[j].height > ret[i].baseHeight) // j部分遮住了i
{
TriangleBound tt = ret[i]; // 更新i的可见度
tt.baseHeight = Math.Max(ret[j].height, tt.baseHeight); // 地形
ret[i] = tt;
}
}
}
}
return(ret);
}
