判断某个坐标是否在 某几个坐标所构成的区域（或不规则区域）内
package com.handle.util;
import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.util.List;
//根据经纬度判断某个点是否在某个区域内
public class Transformation_long_lat {
public static void main(String[] args) {
// 被检测的经纬度点
String X="116.377872";
String Y="39.91103";
// 商业区域（百度多边形区域经纬度集合）
String partitionLocation = "116.377679_39.911113,116.378052_39.911085,116.378047_39.910933,116.377679_39.910937";
System.out.println(isInPolygon(X,Y,partitionLocation));
}
/**
* 判断当前位置是否在多边形区域内
* @param orderLocation 当前点
* @param partitionLocation 区域顶点
* @return
*/
public static boolean isInPolygon(String X,String Y,String partitionLocation){
double p_x =Double.parseDouble(X);
double p_y =Double.parseDouble(Y);
Point2D.Double point = new Point2D.Double(p_x, p_y);
List<Point2D.Double> pointList= new ArrayList<Point2D.Double>();
String[] strList = partitionLocation.split(",");
for (String str : strList){
String[] points = str.split("_");
double polygonPoint_x=Double.parseDouble(points[0]);
double polygonPoint_y=Double.parseDouble(points[1]);
Point2D.Double polygonPoint = new Point2D.Double(polygonPoint_x,polygonPoint_y);
pointList.add(polygonPoint);
}
return IsPtInPoly(point,pointList);
}
/**
* 返回一个点是否在一个多边形区域内， 如果点位于多边形的顶点或边上，不算做点在多边形内，返回false
* @param point
* @param polygon
* @return
*/
public static boolean checkWithJdkGeneralPath(Point2D.Double point, List<Point2D.Double> polygon) {
java.awt.geom.GeneralPath p = new java.awt.geom.GeneralPath();
Point2D.Double first = polygon.get(0);
p.moveTo(first.x, first.y);
polygon.remove(0);
for (Point2D.Double d : polygon) {
p.lineTo(d.x, d.y);
}
p.lineTo(first.x, first.y);
p.closePath();
return p.contains(point);
}
/**
* 判断点是否在多边形内，如果点位于多边形的顶点或边上，也算做点在多边形内，直接返回true
* @param point 检测点
* @param pts 多边形的顶点
* @return 点在多边形内返回true,否则返回false
*/
public static boolean IsPtInPoly(Point2D.Double point, List<Point2D.Double> pts){
int N = pts.size();
boolean boundOrVertex = true; //如果点位于多边形的顶点或边上，也算做点在多边形内，直接返回true
int intersectCount = 0;//cross points count of x
double precision = 2e-10; //浮点类型计算时候与0比较时候的容差
Point2D.Double p1, p2;//neighbour bound vertices
Point2D.Double p = point; //当前点
p1 = pts.get(0);//left vertex
for(int i = 1; i <= N; ++i){//check all rays
if(p.equals(p1)){
return boundOrVertex;//p is an vertex
}
p2 = pts.get(i % N);
if(p.x < Math.min(p1.x, p2.x) || p.x > Math.max(p1.x, p2.x)){
p1 = p2;
continue;
}
if(p.x > Math.min(p1.x, p2.x) && p.x < Math.max(p1.x, p2.x)){
if(p.y <= Math.max(p1.y, p2.y)){
if(p1.x == p2.x && p.y >= Math.min(p1.y, p2.y)){
return boundOrVertex;
}
if(p1.y == p2.y){
if(p1.y == p.y){
return boundOrVertex;
}else{//before ray
++intersectCount;
}
}else{
double xinters = (p.x - p1.x) * (p2.y - p1.y) / (p2.x - p1.x) + p1.y;
if(Math.abs(p.y - xinters) < precision){
return boundOrVertex;
}
if(p.y < xinters){
++intersectCount;
}
}
}
}else{
if(p.x == p2.x && p.y <= p2.y){
Point2D.Double p3 = pts.get((i+1) % N);
if(p.x >= Math.min(p1.x, p3.x) && p.x <= Math.max(p1.x, p3.x)){
++intersectCount;
}else{
intersectCount += 2;
}
}
}
p1 = p2;
}
if(intersectCount % 2 == 0){//偶数在多边形外
return false;
} else { //奇数在多边形内
return true;
}
}
}