package test;

import java.awt.geom.Line2D;
import javax.swing.JOptionPane;

public class MyLine {
	private Point e1,e2;
	
	public MyLine() {
		e1 = new Point(0.0 , 0.0);
		e2 = new Point(0.0 , 0.0);
	}
	
	public MyLine(Point p1 , Point p2) {
		e1 = new Point(p1);
		e2 = new Point(p2);
	}
	
	public MyLine(Point p1) {
		e1 = new Point(0 , 0);
		e2 = new Point(p1);
	}
	
	public Point getE1() {
		return e1;
	}

	public void setE1(Point e1) {
		this.e1 = e1;
	}

	public Point getE2() {
		return e2;
	}

	public void setE2(Point e2) {
		this.e2 = e2;
	}
	
	//线段是否在第一象限
	public boolean check(){
		if(e1.getX() > 0 && e1.getY() > 0 && e2.getX() > 0 && e2.getY() > 0){
			return true;
		}
		else
			return false;
	}
	
	//线段长度
	double length(){
		double leng;
		leng = Math.sqrt( (e1.getX()-e2.getX())*(e1.getX()-e2.getX()) + 
				(e1.getY()-e2.getY())*(e1.getY()-e2.getY())
				);
		return leng;
	}
	
	//判断两条线是否交叉
	boolean intersect(MyLine line2){
		boolean result;
		//Line2D一个java自带类库
		//linesIntersect(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4) 
        //测试从 (x1,y1) 到 (x2,y2) 的线段是否与从 (x3,y3) 到 (x4,y4) 的线段相交。
		//只需要传入两个线段的两个【端点（两个坐标，4个数）】就知道2线段交叉收否
		result = Line2D.linesIntersect(
				getE1().getX() , getE1().getY() ,
				getE2().getX() , getE2().getY() ,
				line2.getE1().getX() , line2.getE1().getY() ,
				line2.getE2().getX() , line2.getE2().getY()
				);
		
		return result;
	}
	
	//点到线的距离
	double distance(Point p){
		double result;
		result = Line2D.ptLineDist(
				getE1().getX(), getE1().getY(), getE2().getX(), getE2().getY(), //线
				p.getX(), p.getY() //点
				);
		
		return result;
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		boolean result;
		MyLine line1 , line2;
		String s = "请在下面输入第一条直线的两点的坐标。形式（x1,y1,x2,y2）";
		//s1,s2,s3,s4是输入的值
		String s1 = JOptionPane.showInputDialog(s + "\n第一个点的横坐标x1");
		String s2 = JOptionPane.showInputDialog(s + "\n第一个点的纵坐标y1");
		String s3 = JOptionPane.showInputDialog(s + "\n第二个个点的横坐标x2");
		String s4 = JOptionPane.showInputDialog(s + "\n第二个点的横坐标y2");
		
		Point pone = new Point(Double.parseDouble(s1) , Double.parseDouble(s2));
		Point ptwo = new Point(Double.parseDouble(s3) , Double.parseDouble(s4));
		
		s = "请在下面对话框输入第二条直线的两点坐标";
		s1 = JOptionPane.showInputDialog(s + "\n第一个点的横坐标x1");
		s2 = JOptionPane.showInputDialog(s + "\n第一个点的纵坐标y1");
		s3 = JOptionPane.showInputDialog(s + "\n第二个个点的横坐标x2");
		s4 = JOptionPane.showInputDialog(s + "\n第二个点的横坐标y2");

		Point pthree = new Point(Double.parseDouble(s1) , Double.parseDouble(s2));
		Point pfour = new Point(Double.parseDouble(s3) , Double.parseDouble(s4));
		
		s1 = JOptionPane.showInputDialog("请在下面对话框输入一个点的横坐标");
		s2 = JOptionPane.showInputDialog("请在下面对话框输入一个点的纵坐标");
		
		Point pfive = new Point(Double.parseDouble(s1) , Double.parseDouble(s2));
		
		line1 = new MyLine(pone , ptwo);
		line2 = new MyLine(pthree , pfour);
		
		//***象限
		result = line1.check();//是否在第一象限
		if(result){
			System.out.println("line1 在第一象限");
		} else{
			System.out.println("line1不在第一象限");
		}
		
		//***长度
		double length = line1.length();
		System.out.println("line1的长度是："+length);
		
		//***相交
		result = line1.intersect(line2);
		if(result){
			System.out.println("line1和line2相交");
		} else{
			System.out.println("line1和line2不相交");
		}
		
		//***点到线的距离
		double distan = line1.distance(pfive);
		System.out.println("点到line1的距离是：" + distan);
		
	}

}

class Point {
	private double x, y;

	public Point(double x, double y) {
		this.x = x;
		this.y = y;
	}

	public Point() {
		this(0, 0);
	}

	public Point(Point p) {
		this(p.getX(), p.getY());
	}

	public double getX() {
		return x;
	}

	public void setX(double x) {
		this.x = x;
	}

	public double getY() {
		return y;
	}

	public void setY(double y) {
		this.y = y;
	}

	public void moveTo(double x1, int y1) {
		x = x1;
		y = y1;
	}

}