feat: 测绘航线生成算法优化，航测区域禁止绘制凹多边形。

GISControlDlg.rc

@@ -397,7 +397,7 @@ BEGIN
     COMBOBOX        IDC_COMBO_DIRECTION,67,49,73,63,CBS_DROPDOWNLIST | CBS_SORT | WS_VSCROLL | WS_TABSTOP
 END
 
-IDD_DLG_DESIGNSURVEYLINE DIALOGEX 0, 0, 211, 119
+IDD_DLG_DESIGNSURVEYLINE DIALOGEX 0, 0, 211, 138
 STYLE DS_SETFONT | DS_MODALFRAME | DS_FIXEDSYS | WS_POPUP | WS_CAPTION | WS_SYSMENU
 CAPTION "航测航线设计"
 FONT 8, "MS Shell Dlg", 400, 0, 0x1
@@ -406,18 +406,20 @@ BEGIN
     EDITTEXT        IDC_EDIT_HEIGHT,70,11,41,15,ES_AUTOHSCROLL,WS_EX_RIGHT
     LTEXT           "航线间隔(m):",IDC_STATIC,10,32,57,10
     EDITTEXT        IDC_EDIT_LINEINTERVAL,70,29,41,15,ES_AUTOHSCROLL,WS_EX_RIGHT
-    PUSHBUTTON      "导入航测区",IDC_BTN_INPUTREGION,10,68,55,18
-    PUSHBUTTON      "绘制航测区",IDC_BTN_DRAWREGION,69,68,55,18
-    PUSHBUTTON      "保存航测区",IDC_BTN_SAVEREGION,128,68,55,18
-    PUSHBUTTON      "装订航线",IDC_BTN_BINDLINE,10,90,55,18
-    PUSHBUTTON      "生成航线",IDC_BTN_CALCULATELINE,69,90,55,18
+    PUSHBUTTON      "导入航测区",IDC_BTN_INPUTREGION,10,90,55,18
+    PUSHBUTTON      "绘制航测区",IDC_BTN_DRAWREGION,69,90,55,18
+    PUSHBUTTON      "保存航测区",IDC_BTN_SAVEREGION,128,90,55,18
+    PUSHBUTTON      "装订航线",IDC_BTN_BINDLINE,10,112,55,18
+    PUSHBUTTON      "生成航线",IDC_BTN_CALCULATELINE,69,112,55,18
     LTEXT           "航程:",IDC_STATIC,114,14,44,10
     LTEXT           "0 m",IDC_TXT_ROUTELENGTH,140,14,50,10
     LTEXT           "航时:",IDC_STATIC,115,32,44,10
-    LTEXT           "飞行速度(m/s):",IDC_STATIC,6,50,66,10
-    EDITTEXT        IDC_EDIT_FLYSPEED,70,47,41,15,ES_AUTOHSCROLL,WS_EX_RIGHT
-    PUSHBUTTON      "航时计算",IDC_BTN_CALCULATETIME,123,46,52,16
+    LTEXT           "飞行速度(m/s):",IDC_STATIC,6,68,66,10
+    EDITTEXT        IDC_EDIT_FLYSPEED,70,65,41,15,ES_AUTOHSCROLL,WS_EX_RIGHT
+    PUSHBUTTON      "航时计算",IDC_BTN_CALCULATETIME,123,64,52,16
     LTEXT           "0时0分0秒",IDC_TXT_FLYTIME,141,32,59,10
+    LTEXT           "航线外扩(m):",IDC_STATIC,10,49,57,10
+    EDITTEXT        IDC_EDIT_EXTERNALLENGTH,70,46,41,15,ES_AUTOHSCROLL,WS_EX_RIGHT
 END
 
 IDD_DLG_SETMULTIROUTE DIALOGEX 0, 0, 210, 159
@@ -574,7 +576,7 @@ BEGIN
         LEFTMARGIN, 3
         RIGHTMARGIN, 207
         TOPMARGIN, 3
-        BOTTOMMARGIN, 114
+        BOTTOMMARGIN, 134
     END
 
     IDD_DLG_SETMULTIROUTE, DIALOG

GISDlg.cpp

@@ -1932,8 +1932,24 @@ void CGISDlg::MouseDownMap1(short Button, short Shift, long x, long y)
 		//像素坐标转换地理坐标
 		m_map.PixelToProj(x,y, &dX, &dY);
 
-		surveyRegionLons.push_back(dX);
-		surveyRegionLats.push_back(dY);
+		if (surveyRegionLons.size()>2)
+		{
+			TopologicalAnalysis analysis;
+			Point2D p;
+			p.x = dX;
+			p.y = dY;
+			if(!analysis.isPointInPolygon(p,surveyRegionLons,surveyRegionLats)) //禁止绘制凹多边形
+			{
+				surveyRegionLons.push_back(dX);
+				surveyRegionLats.push_back(dY);
+			}
+		}
+		else
+		{
+			surveyRegionLons.push_back(dX);
+			surveyRegionLats.push_back(dY);
+		}
+
 	}
 	
 	if (m_bHaveShowDistanceDlg && (Button == 1))

TopologicalAnalysis.cpp

@@ -263,11 +263,13 @@ bool TopologicalAnalysis::GetBoundingBoxVertices(const vector<double>& polygonX,
 }
 
 //计算直线与多边形的交点
-void TopologicalAnalysis::linePolygonIntersections(const Point2D& linePt1,const Point2D& linePt2,const vector<double>& polygonX,const vector<double>& polygonY, vector<Point2D>& result)
+int TopologicalAnalysis::linePolygonIntersections(const Point2D& linePt1,const Point2D& linePt2,const vector<double>& polygonX,const vector<double>& polygonY, vector<Point2D>& result)
 {
+
 	Line2D line1;
 	line1.p1 = linePt1;
 	line1.p2 = linePt2;
+	line1.is_seg = false;
 	Point2D intersectionPt;
 	vector<Point2D> resPoints;
 	for (int i=0;i<polygonX.size()-1;++i)
@@ -280,15 +282,34 @@ void TopologicalAnalysis::linePolygonIntersections(const Point2D& linePt1,const
 		Line2D line2;
 		line2.p1 = pt1;
 		line2.p2 = pt2;
+		line2.is_seg = false;
 
+/*
 		int type = isLineIntersecting(line1,line2,intersectionPt);
 		if (type == 1 || type == 2) //相交或重合
+		{
+			resPoints.push_back(intersectionPt);
+		}*/
+
+/*
+		if (isSegIntersect(line1,line2,intersectionPt))
+		{
+			line2.is_seg = true;
+			if (isponl(intersectionPt,line2))
+			{
+				resPoints.push_back(intersectionPt);
+			}	
+			//resPoints.push_back(intersectionPt);
+		}*/
+
+		
+		if (findIntersection(linePt1.x,linePt1.y,linePt2.x,linePt2.y,pt1.x,pt1.y,pt2.x,pt2.y,intersectionPt))
 		{
 			resPoints.push_back(intersectionPt);
 		}
 	}
 
-	if (resPoints.size()>0)
+	if (resPoints.size()>1)
 	{
 		//获取最左或者最右的两个点,忽略凹多边形中间交点
 		double minX = resPoints[0].x;
@@ -304,6 +325,8 @@ void TopologicalAnalysis::linePolygonIntersections(const Point2D& linePt1,const
 		result.push_back(resPoints[maxIndex]);
 	}
 
+	return resPoints.size();
+
 }
 
 // 判断两条线段是否相交
@@ -332,8 +355,121 @@ int TopologicalAnalysis::isLineIntersecting(const Line2D& l1, const Line2D& l2,
 		intersection.x = l1.p1.x + ua*(l1.p2.x - l1.p1.x);
 		intersection.y = l1.p1.y + ua*(l1.p2.y - l1.p1.y);
 
+/*
+		double a1 = l1.p2.y - l1.p1.y;
+		double b1 = l1.p1.x - l1.p2.x;
+		double c1 = l1.p2.x * l1.p1.y - l1.p1.x * l1.p2.y;
+
+		double a2 = l2.p2.y - l2.p1.y;
+		double b2 = l2.p1.x - l2.p2.x;
+		double c2 = l2.p2.x * l2.p1.y - l2.p1.x * l2.p2.y;
+		double det = a1 * b2 - a2 * b1;
+
+		intersection.x = (b2 * c1 - b1 * c2) / det;
+		intersection.y = (a1 * c2 - a2 * c1) / det;*/
+
 		return 1; //相交
 	}
 
 	return 0; //不相交
 }
+
+//计算多边形最小宽度
+int TopologicalAnalysis::getLineWithPolygonMinWidth(const vector<double>& polygonX,const vector<double>& polygonY)
+{
+	int n = polygonX.size();
+	double minWidth = INT64_MAX;
+	int lineID = 0;
+
+	for (int i=0;i<n-1;++i) //遍历每一条边
+	{
+		int startID = i;
+		int endID = i + 1;
+		double width = 0;
+		for (int j=0;j<n-1;++j) //计算除边两个顶点外多边形其他顶点到直线的距离
+		{
+			if(startID == j || endID == j || (endID== n-1 && j==0)) continue;
+			//计算垂足点
+			double linePt1[2] = {polygonX[startID],polygonY[startID]};
+			double linePt2[2] = {polygonX[endID],polygonY[endID]};
+			double targetPt[2] = {0.0,0.0};
+			double pt[2] = {polygonX[j],polygonY[j]};
+			GetPointToLineVerticalCross(linePt1,linePt2,pt,targetPt);
+			//计算距离
+			double dist;
+			CalculateTwoPtsDistance(dist,pt[0],pt[1],targetPt[0],targetPt[1],3);
+			if(dist > width) width = dist;
+		}
+		if(width < minWidth)
+		{
+			minWidth = width;
+			lineID = startID;
+		}
+	}
+	
+	return lineID;
+}
+
+//判断点与直线的位置关系
+int TopologicalAnalysis::pointPosition(const Point2D& pt,const Line2D& line)
+{
+	double cross = crossProduct(line.p1, line.p2, pt);
+	if (cross > 0) {
+		return 1; //左侧
+	} else if (cross < 0) {
+		return -1; //右侧
+	} else {
+		return 0; //线上
+	}
+}
+
+
+// 判断点P是否在多边形polygon内
+bool TopologicalAnalysis::isPointInPolygon(const Point2D& P, vector<double>& regionLons,vector<double>& regionLats) {
+	int n =  regionLons.size();
+	bool inside = false;
+	double xints;
+	for(int i=0, j=n-1; i<n; j=i++) {
+		double xi =  regionLons[i], yi = regionLats[i];
+		double xj =  regionLons[j], yj = regionLats[j];
+
+		// 点在多边形的顶点上也是一种特殊情况，这里简化处理未包含
+		// 检查射线是否与当前边相交
+		if(((yi > P.y) != (yj > P.y)) && // 边的两端点在射线两侧
+			(P.x < (xj - xi) * (P.y - yi) / (yj - yi) + xi)) { // 射线与边相交的条件
+				inside = !inside; // 交点数加一，改变inside状态
+		}
+	}
+	return inside;
+}
+
+//直线与线段的交点
+bool TopologicalAnalysis::findIntersection(double x1, double y1, double x2, double y2, // 直线1的两个点
+	double x3, double y3, double x4, double y4,Point2D& intersection) { // 线段的两个端点
+		// 计算直线1的方向向量
+		double dx1 = x2 - x1;
+		double dy1 = y2 - y1;
+
+		// 计算线段的方向向量
+		double dx2 = x4 - x3;
+		double dy2 = y4 - y3;
+
+		// 计算向量积，判断是否平行（即无交点）
+		double cross = -dx1 * dy2 + dy1 * dx2;
+		if (cross == 0) return false;
+
+		// 计算参数t1（直线1上的点）和t2（线段上的点）
+		double t1 = (dx2 * (y3 - y1) - dy2 * (x3 - x1)) / cross;
+		double t2 = (dx1 * (y3 - y1) - dy1 * (x3 - x1)) / cross;
+
+		// 判断t2是否在线段上
+		if (t2 >= 0 && t2 <= 1) {
+			// 计算并返回交点坐标
+			intersection.x = x1 + t1 * dx1;
+			intersection.y = y1 + t1 * dy1;
+			return true;
+		} else {
+			// 如果t2不在[0, 1]区间内，说明不相交于线段上
+			return false;
+		}
+}

TopologicalAnalysis.h

@@ -5,14 +5,26 @@
 #include <algorithm>
 #include <limits>
 #include "geocompute.h"
+#include <cstdint>
 using namespace std;
 
 struct Point2D {
-	double x, y;
+	//double x, y;
+	double x;	// x坐标
+	double y;	// y坐标
+	double z;	// z坐标（默认为0，如果需要三维点则给z赋值）
+
+	Point2D(double a = 0, double b = 0, double c = 0) { x = a; y = b; z = c; } // 构造函数
 };
 
 struct Line2D {
-	Point2D p1, p2;
+	//Point2D p1, p2;
+	Point2D p1;	// 起点
+	Point2D p2;	// 终点
+	bool is_seg; // 是否是线段
+
+	Line2D() {};	// 默认构造函数
+	Line2D(Point2D a, Point2D b, bool _is_seg = true) { p1 = a; p2 = b; is_seg = _is_seg; }	// 构造函数(默认是线段)
 };
 
 struct Rectangle2D {
@@ -55,12 +67,230 @@ public:
 	bool GetBoundingBoxVertices(const vector<double>& polygonX,const vector<double>& polygonY,vector<double>& rectangleX,vector<double>& rectangleY);
 
 	//计算直线与多边形的交点
-	void linePolygonIntersections(const Point2D& linePt1,const Point2D& linePt2,const vector<double>& polygonX,const std::vector<double>& polygonY,std::vector<Point2D>& result);
+	int linePolygonIntersections(const Point2D& linePt1,const Point2D& linePt2,const vector<double>& polygonX,const std::vector<double>& polygonY,std::vector<Point2D>& result);
+
+	/** 计算多边形最小宽度对应的边
+	 * param: polygonX,polygonY,多边形顶点坐标(首尾坐标相同)
+	 * return: 返回线段起始点ID号
+	 */
+	int getLineWithPolygonMinWidth(const vector<double>& polygonX,const vector<double>& polygonY);
 
+	//判断点与直线的位置关系
+	int pointPosition(const Point2D& pt,const Line2D& line);
 
+	// 判断点P是否在多边形polygon内
+	bool isPointInPolygon(const Point2D& P, vector<double>& regionLons,vector<double>& regionLats);
 private:
 	// 判断两条线段是否相交   
 	int isLineIntersecting(const Line2D& l1, const Line2D& l2, Point2D& intersection);
+
+	//数学计算
+private:
+	//计算两点（向量）的点积
+	double dotProduct(const Point2D& p1, const Point2D& p2) {
+		return p1.x * p2.x + p1.y * p2.y;
+	}
+	//计算两个点（向量）之间的差向量
+	Point2D subtract(const Point2D& p1, const Point2D& p2) {
+		Point2D point;
+		point.x = p1.x - p2.x;
+		point.y = p1.y - p2.y;
+		return point;
+	}
+
+	//计算向量叉积
+	double crossProduct(const Point2D& A, const Point2D& B, const Point2D& P) {
+		return (B.x - A.x) * (P.y - A.y) - (B.y - A.y) * (P.x - A.x);
+	}
+
+/*
+	double length(const Point2D& p) {
+		return std::sqrt(p.x * p.x + p.y * p.y);
+	}*/
+
+/*
+	Point2D normalize(const Point2D& p) {
+		double len = length(p);
+		Point2D pt;
+		pt.x = p.x / len;
+		pt.y = p.y / len;
+		return pt;
+	}*/
+
+private:
+	// 点的加法
+	Point2D add(const Point2D& lhs, const Point2D& rhs)
+	{
+		Point2D res;
+
+		res.x = lhs.x + rhs.x;
+		res.y = lhs.y + rhs.y;
+		res.z = lhs.z + rhs.z;
+
+		return res;
+	}
+	// 点的减法
+	Point2D sub(const Point2D& lhs, const Point2D& rhs)
+	{
+		Point2D res;
+
+		res.x = lhs.x - rhs.x;
+		res.y = lhs.y - rhs.y;
+		res.z = lhs.z - rhs.z;
+
+		return res;
+	}
+	// 向量的乘法
+	Point2D mul(const Point2D& p, double ratio)
+	{
+		Point2D res;
+
+		res.x = p.x * ratio;
+		res.y = p.y * ratio;
+		res.z = p.z * ratio;
+
+		return res;
+	}
+	// 向量的除法
+	Point2D div(const Point2D& p, double ratio)
+	{
+		Point2D res;
+
+		res.x = p.x / ratio;
+		res.y = p.y / ratio;
+		res.z = p.z / ratio;
+
+		return res;
+	}
+
+	// 点判断相等
+	bool equal(const Point2D& lhs, const Point2D& rhs)
+	{
+		return(lhs.x == rhs.x && lhs.y == rhs.y && lhs.z == rhs.z);
+	}
+
+	// 1.3、矢量标准化（矢量的长度规约到1）
+	//
+	// 参数： vec ： 矢量
+	//
+	Point2D normalize(const Point2D& vec)
+	{
+		Point2D res;
+
+		res = div(vec, length(vec));
+
+		return res;
+	}
+
+	// 1.9、点是否在线上
+	// 线分为直线和线段，直线表示的是直线是否经过点
+	//
+	// 参数：p : 点  l : 线段或者线
+	// 
+	bool isponl(const Point2D& p, const Line2D& l)
+	{
+		Point2D line_vec = sub(l.p2, l.p1);
+		Point2D point_vec1 = sub(p, l.p1);
+		Point2D point_vec2 = sub(p, l.p2);
+
+		Point2D mul_vec = multiply(line_vec, point_vec1);
+		double dot = dotMultiply(point_vec1, point_vec2);
+		// 点是否在线段上
+		if (l.is_seg)
+		{
+			if (equal(p, l.p1) || equal(p, l.p2))
+				return true;
+			return (0.0 == length(mul_vec) && dot < 0.0);
+
+		}
+		// 点是否在直线上
+		else
+		{
+			return (0.0 == length(mul_vec));
+		}
+	}
+
+	// 1.4、矢量点乘
+	//
+	// 参数：(p1-op)为矢量1，（p2-op）为矢量2
+	//
+	double dotMultiply(const Point2D& op, const Point2D& p1, const Point2D& p2)
+	{
+		return ((p1.x - op.x) * (p2.x - op.x) + (p1.y - op.y) * (p2.y - op.y) + (p1.z - op.z) * (p2.z - op.z));
+	}
+	// 参数：vec1为矢量1，vec2为矢量2
+	//
+	double dotMultiply(const Point2D& vec1, const Point2D& vec2)
+	{
+		return(vec1.x * vec2.x + vec1.y * vec2.y + vec1.z * vec2.z);
+	}
+
+	// 1.5、矢量叉乘
+	//
+	// 参数：(p1-op)为矢量1，（p2-op）为矢量2
+	// 
+	Point2D multiply(const Point2D& op, const Point2D& p1, const Point2D& p2)
+	{
+		Point2D result;
+
+		result.x = (p1.y - op.y) * (p2.z - op.z) - (p2.y - op.y) * (p1.z - op.z);
+		result.y = (p1.z - op.z) * (p2.x - op.x) - (p2.z - op.z) * (p1.x - op.x);
+		result.z = (p1.x - op.x) * (p2.y - op.y) - (p2.x - op.x) * (p1.y - op.y);
+
+		return result;
+	}
+
+	// 参数： vec1为矢量1，vec2为矢量2
+	//
+	Point2D multiply(const Point2D& vec1, const Point2D& vec2)
+	{
+		Point2D result;
+
+		result.x = vec1.y * vec2.z - vec2.y * vec1.z;
+		result.y = vec1.z * vec2.x - vec2.z * vec1.x;
+		result.z = vec1.x * vec2.y - vec2.x * vec1.y;
+
+		return result;
+	}
+
+	// 参数： vec1 矢量1  vec2 矢量2
+	// 
+	double Cos(const Point2D& vec1, const Point2D& vec2)
+	{
+		Point2D unit_vec1 = normalize(vec1);
+		Point2D unit_vec2 = normalize(vec2);
+
+		return dotMultiply(unit_vec1, unit_vec2);
+	}
+
+	// 1.2、矢量的长度
+	//
+	// 参数： vec 矢量
+	//
+	double length(const Point2D& vec)
+	{
+		return (sqrt(pow(vec.x, 2) + pow(vec.y, 2) + pow(vec.z, 2)));
+	}
+
+
+
+
+	// 计算两点之间的向量
+	Point2D mathVector(const Point2D& p1, const Point2D& p2) {
+		Point2D pt;
+		pt.x = p2.x - p1.x;
+		pt.y = p2.y - p1.y;
+		return pt;
+	}
+	// 计算两点之间的叉积
+	double crossProduct(const Point2D& p1, const Point2D& p2) {
+		return p1.x * p2.y - p1.y * p2.x;
+	}
+
+	//直线与线段的交点
+	bool findIntersection(double x1, double y1, double x2, double y2, // 直线1的两个点
+		double x3, double y3, double x4, double y4,Point2D& intersection);
+
 };
 
 

designsurveylinedlg.cpp

@@ -48,8 +48,8 @@ BOOL DesignSurveyLineDlg::OnInitDialog()
 	GetDlgItem( IDC_BTN_CALCULATELINE )->EnableWindow( false );
 	GetDlgItem( IDC_BTN_CALCULATETIME )->EnableWindow( false );
 	SetDlgItemText(IDC_EDIT_FLYSPEED,"10");
+	SetDlgItemText(IDC_EDIT_EXTERNALLENGTH,"0");
 
-	
 	return TRUE;
 }
 
@@ -76,6 +76,8 @@ CString DesignSurveyLineDlg::extractFileName(CString fileName)
 //设置航测区域
 void DesignSurveyLineDlg::SetSurveyRegion(const vector<double>& lons,const vector<double>& lats)
 {
+	surveyRegionLons.clear();
+	surveyRegionLats.clear();
 	for (int i=0;i<lons.size();++i)
 	{
 		surveyRegionLons.push_back(lons[i]);
@@ -85,39 +87,108 @@ void DesignSurveyLineDlg::SetSurveyRegion(const vector<double>& lons,const vecto
 }
 
 //计算测绘航线
-void DesignSurveyLineDlg::calculateSurveyLine(double lineInterval,vector<double>&surveyLineLons,vector<double>& surveyLineLats)
+void DesignSurveyLineDlg::calculateSurveyLine(double lineInterval,vector<double>&surveyLineLons,vector<double>& surveyLineLats,double outLength)
 {
 	vector<double> recLons;
 	vector<double> recLats;
 	TopologicalAnalysis analysis;
 	GeoCompute geocompute;
-	analysis.GetBoundingBoxVertices(surveyRegionLons,surveyRegionLats,recLons,recLats);
+	//计算外包矩形
+	//analysis.GetBoundingBoxVertices(surveyRegionLons,surveyRegionLats,recLons,recLats);
+
+	int startPt1 = analysis.getLineWithPolygonMinWidth(surveyRegionLons,surveyRegionLats);
+	recLons.push_back(surveyRegionLons[startPt1]);
+	recLons.push_back(surveyRegionLons[startPt1+1]);
+	recLats.push_back(surveyRegionLats[startPt1]);
+	recLats.push_back(surveyRegionLats[startPt1+1]);
+	double flyAngle;//飞行航向
+	CalculateTwoPtsAzimuth(flyAngle,surveyRegionLons[startPt1],surveyRegionLats[startPt1],surveyRegionLons[startPt1+1],surveyRegionLats[startPt1+1],3);
+	//计算偏移航向
+	Line2D line;
+	line.p1.x = surveyRegionLons[startPt1];
+	line.p1.y = surveyRegionLats[startPt1];
+	line.p2.x = surveyRegionLons[startPt1 + 1];
+	line.p2.y = surveyRegionLats[startPt1 + 1];
+	Point2D p; //直线的下一个顶点
+	if (startPt1+1 == (surveyRegionLons.size()-1)) //直线为多边形最后一条边
+	{
+		p.x = surveyRegionLons[1];
+		p.y = surveyRegionLats[1];
+	}
+	else 
+	{
+		p.x = surveyRegionLons[startPt1 + 2];
+		p.y = surveyRegionLats[startPt1 + 2];
+	}
+	int ptPos = analysis.pointPosition(p,line);
+	if (ptPos == 1) //左侧
+	{
+		int i = (flyAngle + 270)/360;
+		flyAngle = (flyAngle + 270) - 360*i;
+	}
+	else if(ptPos == -1) //右侧
+	{
+		int i = (flyAngle + 90)/360;
+		flyAngle = (flyAngle + 90) - 360*i;
+	}
+
 	double lon1,lat1,lon2,lat2;
 	//第一条切割线为航线间隔一半
-	geocompute.computeOffsetGeoPosition(recLons[0],recLats[0],180,lineInterval/2000,lon1,lat1);
-	geocompute.computeOffsetGeoPosition(recLons[1],recLats[1],180,lineInterval/2000,lon2,lat2);
+	geocompute.computeOffsetGeoPosition(recLons[0],recLats[0],flyAngle,lineInterval/2000,lon1,lat1);
+	geocompute.computeOffsetGeoPosition(recLons[1],recLats[1],flyAngle,lineInterval/2000,lon2,lat2);
 	Point2D pt1,pt2;
 	pt1.x = lon1;
 	pt1.y = lat1;
 	pt2.x = lon2;
 	pt2.y = lat2;
 	vector<Point2D> result;
-	analysis.linePolygonIntersections(pt1,pt2,surveyRegionLons,surveyRegionLats,result);
+	//交点个数
+	int nCrossPt = analysis.linePolygonIntersections(pt1,pt2,surveyRegionLons,surveyRegionLats,result);
 
-	while(lat1>recLats[2]){
+	while(nCrossPt>1){
 		//平移切割线
-		geocompute.computeOffsetGeoPosition(lon1,lat1,180,lineInterval/1000,lon1,lat1);
-		geocompute.computeOffsetGeoPosition(lon2,lat2,180,lineInterval/1000,lon2,lat2);
+		geocompute.computeOffsetGeoPosition(lon1,lat1,flyAngle,lineInterval/1000,lon1,lat1);
+		geocompute.computeOffsetGeoPosition(lon2,lat2,flyAngle,lineInterval/1000,lon2,lat2);
 		pt1.x = lon1;
 		pt1.y = lat1;
 		pt2.x = lon2;
 		pt2.y = lat2;
 		//计算交点
-		analysis.linePolygonIntersections(pt1,pt2,surveyRegionLons,surveyRegionLats,result);
+		nCrossPt = analysis.linePolygonIntersections(pt1,pt2,surveyRegionLons,surveyRegionLats,result);
+
+	}
+	
+	int nlinePts = result.size();
+	if (nlinePts%2!=0)
+	{
+		nlinePts--;
+	}
+	//计算外扩航点
+	if (nlinePts>1 && outLength>0)
+	{
+		double angle;
+		CalculateTwoPtsAzimuth(angle,result[0].x,result[0].y,result[1].x,result[1].y,3);
+		//计算外扩航向
+		double outAngle1,outAngle2;
+		outAngle2 = angle;
+		int n = (angle + 180)/360;
+		outAngle1 = (angle + 180) - 360*n;
+		geocompute.computeOffsetGeoPosition(result[1].x,result[1].y,outAngle2,outLength/1000,lon2,lat2);
+		result[1].x = lon2;
+		result[1].y = lat2;
+		for (int i=2;i<nlinePts;i+=2)
+		{
+			geocompute.computeOffsetGeoPosition(result[i].x,result[i].y,outAngle1,outLength/1000,lon1,lat1);
+			geocompute.computeOffsetGeoPosition(result[i+1].x,result[i+1].y,outAngle2,outLength/1000,lon2,lat2);
+			result[i].x = lon1;
+			result[i].y = lat1;
+			result[i+1].x = lon2;
+			result[i+1].y = lat2;
+		}
 	}
 	//串联交点
-	int j = 1;
-	for (int i=0;i<result.size();i+=2)
+	int j = 0;
+	for (int i=0;i<nlinePts;i+=2)
 	{
 		if (j == 1)
 		{
@@ -336,12 +407,20 @@ void DesignSurveyLineDlg::OnBnClickedBtnCalculateline()
 		return;
 	}
 
+	GetDlgItemText(IDC_EDIT_EXTERNALLENGTH,cstr);
+	double outLength = _ttof(cstr);
+	if (outLength < 0 )
+	{
+		BCGPMessageBox("外扩长度必须大于0m");
+		return;
+	}
+
 	g_Height = height;
 	//测绘航线坐标
 	vector<double> surveyLineLons;
 	vector<double> surveyLineLats;
 	//计算航测航线
-	calculateSurveyLine(lineInterval,surveyLineLons,surveyLineLats);
+	calculateSurveyLine(lineInterval,surveyLineLons,surveyLineLats,outLength);
 	//保存航测航线
 	saveSurveyLine(surveyLineLons,surveyLineLats,height);
 	//发送消息到主程序，进行标绘

designsurveylinedlg.h

@@ -28,7 +28,7 @@ public:
 	enum { IDD = IDD_DLG_DESIGNSURVEYLINE };
 
 private:
-	void calculateSurveyLine(double lineInterval,vector<double>&surveyLineLons,vector<double>& surveyLineLats);//¼ÆËã²â»æº½Ïß
+	void calculateSurveyLine(double lineInterval,vector<double>&surveyLineLons,vector<double>& surveyLineLats,double outLength=0);//¼ÆËã²â»æº½Ïß
 	void saveSurveyLine(const vector<double>&surveyLineLons,const vector<double>& surveyLineLats,double height); //保存测绘航线
 	bool saveSurveyRegion(const vector<double>&surveyRegionLons,const vector<double>& surveyRegionLats); //保存航测区域
 	double calculateRouteLength(const vector<double>&surveyLineLons,const vector<double>& surveyLineLats); //计算航程

resource.h

@@ -166,9 +166,10 @@
 #define IDC_EDIT_FLYSPEED               1056
 #define IDB_BITMAP2                     1057
 #define IDC_EDIT_MARKER_NAME            1057
-#define IDC_TXT_ROUTELENGTH2            1057
 #define IDC_TXT_FLYTIME                 1057
 #define IDC_TREE_MARKERS                1058
+#define IDC_EDIT_                       1058
+#define IDC_EDIT_EXTERNALLENGTH         1058
 #define IDD_DIALOG_MARKER               1063
 #define IDR_MENU3                       1066
 #define IDR_LIST_POPUP                  1066