/ * *
* 中点画圆算法（八分之一圆）的简单实现，从控制台输入两对坐标，applet程序实现描点画线。
* @author LOOK
*
import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.util.Scanner;
public class MidPointCircle extends Applet {
int a;
public void init() {
setSize(300, 300);
Scanner sc = new Scanner(System.in);
System.out.println("请输入圆的半径");
a = sc.nextInt();
}
public void paint(Graphics g) {
g.setColor(Color.pink);
for (int i = 10; i <= 210; i += 10) {
g.drawLine(i, 10, i, 210);// 竖线
g.drawLine(10, i, 210, i);// 横线
}
g.setColor(Color.BLACK);
g.drawLine(10, 210, 220, 210);// x坐标
g.drawLine(10, 0, 10, 210);// y坐标
int r = a;
int x, y;
double d;
x = 0;
y = r;
d = 1.25 - r;
g.drawOval(x * 10 - 2 + 10, 210 - y * 10 - 2, 4, 4);// 描点
while (x <= y) {
if (d < 0) {
d += 2 * x + 3;
} else {
d += 2 * (x - y) + 5;
y--;
}
x++;
g.drawOval(x * 10 - 2 + 10, 210 - y * 10 - 2, 4, 4);// 描点
}
}
}
