JTS algorithm package

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wx63086371c7e9c 2022-08-26 14:52:12 博主文章分类：JTS ©著作权

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角度分析(Angle)：

com.vividsolutions.jts.algorithm.Angle

Coordinate tip1 = new Coordinate(0,0);
    Coordinate tail = new Coordinate(1,1);
    Coordinate tip2 = new Coordinate(4,3);
    Angle angle = new Angle();
    
    //返回两个无向最小差异角度,范围 [0, 180]
    double radia1 = angle.angle(tip1, tail);
    double radia2 = angle.angle(tail, tip2);
    System.out.println(angle.toDegrees(angle.diff(radia1, radia2)));
    
    //返回两个向量之间的最小夹角,范围[0,180]
    double ang1 = angle.angleBetween(tip1, tail, tip2);
    System.out.println(angle.toDegrees(ang1));
    
    //从angle到angle按什么方向旋转
    // public static final int CLOCKWISE     = -1; 顺时针
    //public static final int COUNTERCLOCKWISE  = 1; 逆时针
    System.out.println(angle.getTurn(radia1, radia2));
    
    // 判断从tip1->tail->tip2的夹角是否是锐角
    System.out.println(angle.isAcute(tip1, tail,tip2));
    
    // 判断从tip1->tail->tip2的夹角是否是钝角
    System.out.println(angle.isObtuse(tip1, tail,tip2));
    
    //角度->弧度的转换
    System.out.println(angle.toDegrees(Math.PI));
    
    //弧度->角度的转换
    System.out.println(angle.toRadians(180));

输出结果：

11.309932474020213
168.6900675259798
-1
false
true
180.0
3.141592653589793

几何的基础算法(CGAlgorithms):

com.vividsolutions.jts.algorithm.CGAlgorithms

GeometryFactory.java

import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.io.ParseException;
import com.vividsolutions.jts.io.WKTReader;

public class GeometryFactory {

  private WKTReader reader;

  private static GeometryFactory instance = null;

  public static synchronized GeometryFactory getInstance() {
    if (instance == null) {
      instance = new GeometryFactory();
    }
    return instance;
  }

  public void getReader() {
    reader = new WKTReader();
  }

  public Geometry buildGeo(String str) {
    try {
      if (reader == null) {
        reader = new WKTReader();
      }
      return reader.read(str);
    } catch (ParseException e) {
      throw new RuntimeException("buildGeometry Error", e);
    }
  }
}

private static GeometryFactory factory = GeometryFactory.getInstance();
    //定义环
    Geometry g = factory.buildGeo("LINESTRING (0 0,1 1,2 2, 5 5,0 5,0 0)");
    Coordinate[] coords = g.getCoordinates();
    //点在环上
    System.out.println(CGAlgorithms.isPointInRing(new Coordinate(4,4), coords));
    //点在环内
    System.out.println(CGAlgorithms.isPointInRing(new Coordinate(1,2), coords));
    
    //计算线段AB到CD的最短距离
    System.out.println(CGAlgorithms.distanceLineLine(new Coordinate(1,1), new Coordinate(2,2), new Coordinate(2,0), new Coordinate(3,0)));
    
    //计算点A到CD的最短距离
    System.out.println(CGAlgorithms.distancePointLine(new Coordinate(0,0), new Coordinate[]{new Coordinate(1,1), new Coordinate(2,0), new Coordinate(2,2), new Coordinate(1,1)}));
    
    //环是否是逆时针旋转导向
    System.out.println(CGAlgorithms.isCCW(new Coordinate[]{new Coordinate(1,1), new Coordinate(2,0), new Coordinate(2,2), new Coordinate(1,1)}));
    
    //点是否在线段上
    System.out.println(CGAlgorithms.isOnLine(new Coordinate(2,1),new Coordinate[]{new Coordinate(2,0), new Coordinate(2,2), new Coordinate(1,1)}));
    
    //求两线的交点，返回的是坐标点。
    HCoordinate hcoord = new HCoordinate(new Coordinate(0,0), new Coordinate(5,5),new Coordinate(0,4),new Coordinate(4,0));
    try {
      System.out.println(hcoord.getX());
      System.out.println(hcoord.getY());
    } catch (NotRepresentableException e1) {
      //抛出此异常，说明两条线段平行。
      e1.printStackTrace();
    }
    
    //等价
    HCoordinate hd = new HCoordinate();
    try {
      System.out.println(hd.intersection(new Coordinate(0,0), new Coordinate(5,5),new Coordinate(0,4),new Coordinate(4,0)));
    } catch (NotRepresentableException e) {
      //抛出此异常，说明两条线段平行。
      e.printStackTrace();
    }
    
    //判断点(Point) 和对象(Geometry) 之间的关系
    //public final static int INTERIOR = 0; 在内部
    //public final static int BOUNDARY = 1; 在边界上
    //public final static int EXTERIOR = 2; 在外部
    //public final static int NONE = -1;
    PointLocator pl = new PointLocator();
    //在线上
    System.out.println(pl.locate(new Coordinate(0,0), factory.buildGeo("LINESTRING (0 0,1 1,2 2, 5 5,0 5)")));
    //在面上
    System.out.println(pl.locate(new Coordinate(0,0), factory.buildGeo("POLYGON ((0 0,1 1,2 2,5 5,0 5,0 0))")));
    //在面内
    System.out.println(pl.locate(new Coordinate(1,3), factory.buildGeo("POLYGON ((0 0,1 1,2 2,5 5,0 5,0 0))")));
    //在面外
    System.out.println(pl.locate(new Coordinate(10,10), factory.buildGeo("POLYGON ((0 0,1 1,2 2,5 5,0 5,0 0))")));