Java绘制心形曲线(笛卡尔曲线)
## 效果图
## 代码
```java
import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
public class CartesianCurve extends Applet {
private static final long serialVersionUID = -1616773050265562622L;
Image image;
Graphics graphics;
int width = 568;
int height = 350;
@Override
public void init() {
setBackground(Color.black);
this.setSize(width, height);
image = createImage(width, height);
graphics = image.getGraphics();
}
@Override
public void paint(Graphics g) {
// 用红色来填充清除指定的矩形。
graphics.clearRect(0, 0, width, height);
graphics.setColor(Color.red);
double x, y, r;
// 笛卡儿数学公式: (x*x+y*y-2ax)2=4a*a(x*x+y*y)
for (int i = 0; i <= 90; i++)
for (int j = 0; j <= 90; j++) {
r = Math.PI / 45 * i * (1 - Math.sin(Math.PI / 45 * j)) * 18;
x = r * Math.cos(Math.PI / 45 * j) * Math.sin(Math.PI / 45 * i) + width / 2;
y = -r * Math.sin(Math.PI / 45 * j) + height / 4;
graphics.fillOval((int) x, (int) y, 2, 2);
}
g.drawImage(image, 0, 0, this);
}
}
```