/// <summary>
/// from http://stackoverflow.com/questions/1119451/how-to-tell-if-a-line-intersects-a-polygon-in-c
/// </summary>
/// <param name="start1"></param>
/// <param name="end1"></param>
/// <param name="start2"></param>
/// <param name="end2"></param>
/// <returns></returns>
public static utmpos FindLineIntersection(utmpos start1, utmpos end1, utmpos start2, utmpos end2)
{
double denom = ((end1.x - start1.x) * (end2.y - start2.y)) - ((end1.y - start1.y) * (end2.x - start2.x));
// AB & CD are parallel
if (denom == 0)
{
return(utmpos.Zero);
}
double numer = ((start1.y - start2.y) * (end2.x - start2.x)) - ((start1.x - start2.x) * (end2.y - start2.y));
double r = numer / denom;
double numer2 = ((start1.y - start2.y) * (end1.x - start1.x)) - ((start1.x - start2.x) * (end1.y - start1.y));
double s = numer2 / denom;
if ((r < 0 || r > 1) || (s < 0 || s > 1))
{
return(utmpos.Zero);
}
// Find intersection point
utmpos result = new utmpos();
result.x = start1.x + (r * (end1.x - start1.x));
result.y = start1.y + (r * (end1.y - start1.y));
result.zone = start1.zone;
return(result);
}
public utmpos(utmpos pos)
{
this.x = pos.x;
this.y = pos.y;
this.zone = pos.zone;
this.Tag = null;
}
// polar to rectangular
static utmpos newpos(utmpos input, double bearing, double distance)
{
double degN = 90 - bearing;
if (degN < 0)
{
degN += 360;
}
double x = input.x + distance * Math.Cos(degN * deg2rad);
double y = input.y + distance * Math.Sin(degN * deg2rad);
return(new utmpos(x, y, input.zone));
}
static utmpos findClosestPoint(utmpos start, List <utmpos> list)
{
utmpos answer = utmpos.Zero;
double currentbest = double.MaxValue;
foreach (utmpos pnt in list)
{
double dist1 = start.GetDistance(pnt);
if (dist1 < currentbest)
{
answer = pnt;
currentbest = dist1;
}
}
return(answer);
}
static bool PointInPolygon(utmpos p, List <utmpos> poly)
{
utmpos p1, p2;
bool inside = false;
if (poly.Count < 3)
{
return(inside);
}
utmpos oldPoint = new utmpos(poly[poly.Count - 1]);
for (int i = 0; i < poly.Count; i++)
{
utmpos newPoint = new utmpos(poly[i]);
if (newPoint.y > oldPoint.y)
{
p1 = oldPoint;
p2 = newPoint;
}
else
{
p1 = newPoint;
p2 = oldPoint;
}
if ((newPoint.y < p.y) == (p.y <= oldPoint.y) &&
((double)p.x - (double)p1.x) * (double)(p2.y - p1.y)
< ((double)p2.x - (double)p1.x) * (double)(p.y - p1.y))
{
inside = !inside;
}
oldPoint = newPoint;
}
return(inside);
}
///// <summary>
/////
///// </summary>
///// <param name="pos"></param>
//static void addtomap(linelatlng pos)
//{
// List<PointLatLng> list = new List<PointLatLng>();
// list.Add(pos.p1.ToLLA());
// list.Add(pos.p2.ToLLA());
// polygons.Routes.Add(new GMapRoute(list, "test") { Stroke = new System.Drawing.Pen(System.Drawing.Color.Yellow, 4) });
// map.ZoomAndCenterRoutes("polygons");
//}
///// <summary>
///// this is a debug function
///// </summary>
///// <param name="pos"></param>
///// <param name="tag"></param>
//static void addtomap(utmpos pos, string tag)
//{
// if (tag == "M")
// return;
// polygons.Markers.Add(new GMapMarkerWP(pos.ToLLA(), tag));
// map.ZoomAndCenterMarkers("polygons");
// map.Invalidate();
//}
//static GMapOverlay polygons = new GMapOverlay("polygons");
//static GMapControl map = new GMapControl();
/// <summary>
/// 关键函数
/// </summary>
/// <param name="polygon">测区范围</param>
/// <param name="altitude">飞行高度</param>
/// <param name="distance">航线间距</param>
/// <param name="spacing">拍照间隔</param>
/// <param name="angle">航线角度</param>
/// <param name="overshoot1">向往扩展1</param>
/// <param name="overshoot2">向外扩张2</param>
/// <param name="startpos">起始航电</param>
/// <param name="shutter">电子快门</param>
/// <param name="minLaneSeparation">最小??</param>
/// <param name="leadin">引导线</param>
/// <returns></returns>
public static List <PointLatLngAlt> CreateGrid(List <PointLatLngAlt> polygon, double altitude, double distance, double spacing, double angle, double overshoot1, double overshoot2, StartPosition startpos, bool shutter, float minLaneSeparation, float leadin = 0)
{
if (spacing < 10 && spacing != 0)
{
spacing = 10;
}
if (distance < 0.1)
{
distance = 0.1;
}
if (polygon.Count == 0)
{
return(new List <PointLatLngAlt>());
}
// Make a non round number in case of corner cases
if (minLaneSeparation != 0)
{
minLaneSeparation += 0.5F;
}
// Lane Separation in meters
double minLaneSeparationINMeters = minLaneSeparation * distance;
List <PointLatLngAlt> ans = new List <PointLatLngAlt>();
// 计算当前经度在墨卡托坐标的哪个带里
// utm zone distance calcs will be done in
int utmzone = polygon[0].GetUTMZone();
// 将经纬度坐标点转成墨卡托坐标
// utm position list
List <utmpos> utmpositions = utmpos.ToList(PointLatLngAlt.ToUTM(utmzone, polygon), utmzone);
// 闭合范围
// close the loop if its not already
if (utmpositions[0] != utmpositions[utmpositions.Count - 1])
{
utmpositions.Add(utmpositions[0]); // make a full loop
}
// 获取最小的外包矩形
// get mins/maxs of coverage area
Rect area = getPolyMinMax(utmpositions);
// 计算矩形对角线长度
// get initial grid
// used to determine the size of the outer grid area
double diagdist = area.DiagDistance();
// 好像是保存结果的
// somewhere to store out generated lines
List <linelatlng> grid = new List <linelatlng>();
// 航线条数
// number of lines we need
int lines = 0;
// 区域中点XY
// get start point middle
double x = area.MidWidth;
double y = area.MidHeight;
//addtomap(new utmpos(x, y, utmzone), "Base");
// get left extent
double xb1 = x;
double yb1 = y;
// to the left
newpos(ref xb1, ref yb1, angle - 90, diagdist / 2 + distance);
// backwards
newpos(ref xb1, ref yb1, angle + 180, diagdist / 2 + distance);
utmpos left = new utmpos(xb1, yb1, utmzone);
//addtomap(left, "left");
// get right extent
double xb2 = x;
double yb2 = y;
// to the right
newpos(ref xb2, ref yb2, angle + 90, diagdist / 2 + distance);
// backwards
newpos(ref xb2, ref yb2, angle + 180, diagdist / 2 + distance);
utmpos right = new utmpos(xb2, yb2, utmzone);
//addtomap(right, "right");
// set start point to left hand side
x = xb1;
y = yb1;
// draw the outergrid, this is a grid that cover the entire area of the rectangle plus more.
while (lines < ((diagdist + distance * 2) / distance))
{
// copy the start point to generate the end point
double nx = x;
double ny = y;
newpos(ref nx, ref ny, angle, diagdist + distance * 2);
linelatlng line = new linelatlng();
line.p1 = new utmpos(x, y, utmzone);
line.p2 = new utmpos(nx, ny, utmzone);
line.basepnt = new utmpos(x, y, utmzone);
grid.Add(line);
// addtomap(line);
newpos(ref x, ref y, angle + 90, distance);
lines++;
}
// find intersections with our polygon
// store lines that dont have any intersections
List <linelatlng> remove = new List <linelatlng>();
int gridno = grid.Count;
// cycle through our grid
for (int a = 0; a < gridno; a++)
{
double closestdistance = double.MaxValue;
double farestdistance = double.MinValue;
utmpos closestpoint = utmpos.Zero;
utmpos farestpoint = utmpos.Zero;
// somewhere to store our intersections
List <utmpos> matchs = new List <utmpos>();
int b = -1;
int crosses = 0;
utmpos newutmpos = utmpos.Zero;
foreach (utmpos pnt in utmpositions)
{
b++;
if (b == 0)
{
continue;
}
newutmpos = FindLineIntersection(utmpositions[b - 1], utmpositions[b], grid[a].p1, grid[a].p2);
if (!newutmpos.IsZero)
{
crosses++;
matchs.Add(newutmpos);
if (closestdistance > grid[a].p1.GetDistance(newutmpos))
{
closestpoint.y = newutmpos.y;
closestpoint.x = newutmpos.x;
closestpoint.zone = newutmpos.zone;
closestdistance = grid[a].p1.GetDistance(newutmpos);
}
if (farestdistance < grid[a].p1.GetDistance(newutmpos))
{
farestpoint.y = newutmpos.y;
farestpoint.x = newutmpos.x;
farestpoint.zone = newutmpos.zone;
farestdistance = grid[a].p1.GetDistance(newutmpos);
}
}
}
if (crosses == 0) // outside our polygon
{
if (!PointInPolygon(grid[a].p1, utmpositions) && !PointInPolygon(grid[a].p2, utmpositions))
{
remove.Add(grid[a]);
}
}
else if (crosses == 1) // bad - shouldnt happen
{
}
else if (crosses == 2) // simple start and finish
{
linelatlng line = grid[a];
line.p1 = closestpoint;
line.p2 = farestpoint;
grid[a] = line;
}
else // multiple intersections
{
linelatlng line = grid[a];
remove.Add(line);
while (matchs.Count > 1)
{
linelatlng newline = new linelatlng();
closestpoint = findClosestPoint(closestpoint, matchs);
newline.p1 = closestpoint;
matchs.Remove(closestpoint);
closestpoint = findClosestPoint(closestpoint, matchs);
newline.p2 = closestpoint;
matchs.Remove(closestpoint);
newline.basepnt = line.basepnt;
grid.Add(newline);
}
}
}
// cleanup and keep only lines that pass though our polygon
foreach (linelatlng line in remove)
{
grid.Remove(line);
}
// debug
foreach (linelatlng line in grid)
{
//addtomap(line);
}
if (grid.Count == 0)
{
return(ans);
}
utmpos startposutm;
switch (startpos)
{
default:
case StartPosition.Home:
//startposutm = new utmpos(Host2.cs.HomeLocation);
startposutm = new utmpos(area.Left, area.Bottom, utmzone);
break;
case StartPosition.BottomLeft:
startposutm = new utmpos(area.Left, area.Bottom, utmzone);
break;
case StartPosition.BottomRight:
startposutm = new utmpos(area.Right, area.Bottom, utmzone);
break;
case StartPosition.TopLeft:
startposutm = new utmpos(area.Left, area.Top, utmzone);
break;
case StartPosition.TopRight:
startposutm = new utmpos(area.Right, area.Top, utmzone);
break;
case StartPosition.Point:
startposutm = new utmpos(StartPointLatLngAlt);
break;
}
// find closest line point to startpos
linelatlng closest = findClosestLine(startposutm, grid, 0 /*Lane separation does not apply to starting point*/, angle);
utmpos lastpnt;
// get the closes point from the line we picked
if (closest.p1.GetDistance(startposutm) < closest.p2.GetDistance(startposutm))
{
lastpnt = closest.p1;
}
else
{
lastpnt = closest.p2;
}
// S = start
// E = end
// ME = middle end
// SM = start middle
while (grid.Count > 0)
{
// for each line, check which end of the line is the next closest
if (closest.p1.GetDistance(lastpnt) < closest.p2.GetDistance(lastpnt))
{
utmpos newstart = newpos(closest.p1, angle, -leadin);
newstart.Tag = "S";
//addtomap(newstart, "S");
ans.Add(newstart);
closest.p1.Tag = "SM";
//addtomap(closest.p1, "SM");
ans.Add(closest.p1);
if (spacing > 0)
{
for (int d = (int)(spacing - ((closest.basepnt.GetDistance(closest.p1)) % spacing));
d < (closest.p1.GetDistance(closest.p2));
d += (int)spacing)
{
double ax = closest.p1.x;
double ay = closest.p1.y;
newpos(ref ax, ref ay, angle, d);
var utmpos1 = new utmpos(ax, ay, utmzone)
{
Tag = "M"
};
//addtomap(utmpos1, "M");
ans.Add(utmpos1);
}
}
closest.p2.Tag = "ME";
//addtomap(closest.p2, "ME");
ans.Add(closest.p2);
utmpos newend = newpos(closest.p2, angle, overshoot1);
newend.Tag = "E";
//addtomap(newend, "E");
ans.Add(newend);
lastpnt = closest.p2;
grid.Remove(closest);
if (grid.Count == 0)
{
break;
}
closest = findClosestLine(newend, grid, minLaneSeparationINMeters, angle);
}
else
{
utmpos newstart = newpos(closest.p2, angle, leadin);
newstart.Tag = "S";
//addtomap(newstart, "S");
ans.Add(newstart);
closest.p2.Tag = "SM";
//addtomap(closest.p2, "SM");
ans.Add(closest.p2);
if (spacing > 0)
{
for (int d = (int)((closest.basepnt.GetDistance(closest.p2)) % spacing);
d < (closest.p1.GetDistance(closest.p2));
d += (int)spacing)
{
double ax = closest.p2.x;
double ay = closest.p2.y;
newpos(ref ax, ref ay, angle, -d);
var utmpos2 = new utmpos(ax, ay, utmzone)
{
Tag = "M"
};
//addtomap(utmpos2, "M");
ans.Add(utmpos2);
}
}
closest.p1.Tag = "ME";
//addtomap(closest.p1, "ME");
ans.Add(closest.p1);
utmpos newend = newpos(closest.p1, angle, -overshoot2);
newend.Tag = "E";
//addtomap(newend, "E");
ans.Add(newend);
lastpnt = closest.p1;
grid.Remove(closest);
if (grid.Count == 0)
{
break;
}
closest = findClosestLine(newend, grid, minLaneSeparationINMeters, angle);
}
}
// set the altitude on all points
ans.ForEach(plla => { plla.Alt = altitude; });
return(ans);
}
static linelatlng findClosestLine(utmpos start, List <linelatlng> list, double minDistance, double angle)
{
// By now, just add 5.000 km to our lines so they are long enough to allow intersection
double METERS_TO_EXTEND = 5000000;
double perperndicularOrientation = AddAngle(angle, 90);
// Calculation of a perpendicular line to the grid lines containing the "start" point
/*
* --------------------------------------|------------------------------------------
* --------------------------------------|------------------------------------------
* -------------------------------------start---------------------------------------
* --------------------------------------|------------------------------------------
* --------------------------------------|------------------------------------------
* --------------------------------------|------------------------------------------
* --------------------------------------|------------------------------------------
* --------------------------------------|------------------------------------------
*/
utmpos start_perpendicular_line = newpos(start, perperndicularOrientation, -METERS_TO_EXTEND);
utmpos stop_perpendicular_line = newpos(start, perperndicularOrientation, METERS_TO_EXTEND);
// Store one intersection point per grid line
Dictionary <utmpos, linelatlng> intersectedPoints = new Dictionary <utmpos, linelatlng>();
// lets order distances from every intersected point per line with the "start" point
Dictionary <double, utmpos> ordered_min_to_max = new Dictionary <double, utmpos>();
foreach (linelatlng line in list)
{
// Extend line at both ends so it intersecs for sure with our perpendicular line
utmpos extended_line_start = newpos(line.p1, angle, -METERS_TO_EXTEND);
utmpos extended_line_stop = newpos(line.p2, angle, METERS_TO_EXTEND);
// Calculate intersection point
utmpos p = FindLineIntersection(extended_line_start, extended_line_stop, start_perpendicular_line, stop_perpendicular_line);
// Store it
intersectedPoints[p] = line;
// Calculate distances between interesected point and "start" (i.e. line and start)
double distance_p = start.GetDistance(p);
if (!ordered_min_to_max.ContainsKey(distance_p))
{
ordered_min_to_max.Add(distance_p, p);
}
}
// Acquire keys and sort them.
List <double> ordered_keys = ordered_min_to_max.Keys.ToList();
ordered_keys.Sort();
// Lets select a line that is the closest to "start" point but "mindistance" away at least.
// If we have only one line, return that line whatever the minDistance says
double key = double.MaxValue;
int i = 0;
while (key == double.MaxValue && i < ordered_keys.Count)
{
if (ordered_keys[i] >= minDistance)
{
key = ordered_keys[i];
}
i++;
}
// If no line is selected (because all of them are closer than minDistance, then get the farest one
if (key == double.MaxValue)
{
key = ordered_keys[ordered_keys.Count - 1];
}
// return line
return(intersectedPoints[ordered_min_to_max[key]]);
}
/// <summary>
/// 任务分段
/// </summary>
/// <param name="points">任务航点</param>
/// <param name="distance">每一段任务长度</param>
/// <returns></returns>
public List <utmpos> LineCut(List <utmpos> points, double distance)
{
// 1. 航点坐标转墨卡托
// 2. 任务分段
// 3. 墨卡托转经纬度
// 4. 写数据库
// 结果
List <utmpos> result = new List <utmpos>();
// 创建一个堆栈
Stack <utmpos> stacks = new Stack <utmpos>();
for (int i = points.Count - 1; i >= 0; i--)
{
stacks.Push(points[i]);
}
//
double total = 0;
utmpos frompoint = stacks.Pop();
result.Add(frompoint); // 添加第一个节点
for (; stacks.Count > 0;)
{
utmpos topoint = stacks.Pop();
//
double len = frompoint.GetDistance(topoint);
if (len + total < distance)
{
// 还没有达到极限
result.Add(topoint); // 加到结果
frompoint = topoint; // 记录最后一个点
total = total + len; // 线段累加
continue;
}
else if (len + total > distance)
{
// 剩下长度不够达到下一个节点
double x = 0;
double y = 0;
double dis = distance - total;
GetCutPoint(frompoint.x, frompoint.y, topoint.x, topoint.y, dis, out x, out y); // 计算中间节点
utmpos cutpoint = new utmpos(x, y, frompoint.zone); // 中间节点
result.Add(cutpoint); // 加到结果
result.Add(new utmpos(0, 0, 0)); // 添加分隔 ##
frompoint = cutpoint; // 起始点定义到中间节点
result.Add(frompoint); // 添加起始点
stacks.Push(topoint); // 结束点重新压回堆栈
total = 0; // 总长度归零
continue;
}
else
{
// 刚刚好
result.Add(topoint); // 添加结果
if (stacks.Count > 0)
{
// 如果后面还有数据就继续处理
result.Add(new utmpos(0, 0, 0)); // 添加分隔 ##
frompoint = topoint; // 记录最后一个点
result.Add(frompoint); // 结果添加新的起始点
total = 0; // 总长度归零
}
continue;
}
}
return(result);
}
public double GetDistance(utmpos b)
{
return(Math.Sqrt(Math.Pow(Math.Abs(x - b.x), 2) + Math.Pow(Math.Abs(y - b.y), 2)));
}
