LineString类型GEOS_LINESTRING

double line[] = {-100.0,0.0, 100.0,0.0};
GEOSCoordSequence* seq = GEOSCoordSeq_copyFromBuffer( line, 2, 0, 0);
GEOSGeometry* p1= GEOSGeom_createLineString(seq);
GEOSGeometry* p2= GEOSGeomFromWKT("LINESTRING (100 -100.0,100.0 100.0)");

//判断直线是否相交，相交返回1，否则为0

int n = GEOSIntersects(p1,p2);

//求交点
GEOSGeometry*p3=  GEOSIntersection(p1,p1);

//是否闭合 

GEOSisClosed（p1)

//获取长度

GEOSGeomGetLength(p2,&dis);

//遍历点

double x,y;

int points = GEOSGeomGetNumPoints(p1);

  for (int i=0;i<points;i++)
 {
        GEOSGeometry* p = GEOSGeomGetPointN(p1,i);
        GEOSGeomGetX(p, &x);
        GEOSGeomGetY(p, &y);
        GEOSGeom_destroy(p);
 }

//获取首尾点坐标

GEOSGeometry* p =GEOSGeomGetStartPoint(p1);

GEOSGeometry* p =GEOSGeomGetEndPoint(p1);