Java 用“画一个平滑的圆”;小径;
我可以用Graphics2D制作一个平滑的圆,它自身的构造不会产生“摆动”效果吗?如果是,如何进行?要理解我的意思,您必须运行以下示例:Java 用“画一个平滑的圆”;小径;,java,swing,graphics2d,event-dispatch-thread,Java,Swing,Graphics2d,Event Dispatch Thread,我可以用Graphics2D制作一个平滑的圆,它自身的构造不会产生“摆动”效果吗?如果是,如何进行?要理解我的意思,您必须运行以下示例: import java.awt.Color; import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import javax.swing.*; public class CircleExampl
import java.awt.Color;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.*;
public class CircleExample {
static int angle = 0;
public static void main(String[] args) {
JFrame frame = new JFrame();
new Thread(new Runnable() {
public void run() {
while (true) {
if (angle >= 360) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
angle = 0;
}
angle++;
try {
Thread.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
frame.repaint();
}
}
}).start();
frame.getContentPane().add(new Circle());
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setSize(200, 200);
frame.setVisible(true);
}
static class Circle extends JPanel {
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D gg = (Graphics2D) g;
gg.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
gg.setColor(Color.BLACK);
gg.drawArc(40, 40, 100, 100, 0, angle);
}
}
}
抖动效应是由不同圆弧的抗锯齿决定略有不同引起的,可能是由于舍入误差 解决此问题的一种方法是绘制一个完整的圆(始终以相同的方式进行抗锯齿渲染),但将其剪裁到给定的圆弧。所以只有一部分会被画出来 以下是基于Andrew Thompson基于计时器的答案(已被删除),但我为原始线程添加了一些延迟,并将
角度
设置为圆圈
类的字段,而不是静态变量
public static void main(String[] args) {
final JFrame frame = new JFrame();
frame.getContentPane().add(new Circle());
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setSize(200, 200);
frame.setVisible(true);
}
static class Circle extends JPanel {
private int angle = 0;
// The clip arc is going to be slightly larger than the actual
// arc, otherwise some antialiasing pixels will be clipped off.
private Arc2D clip = new Arc2D.Double(35,35,110,110,0,360,Arc2D.PIE);
Circle() {
ActionListener actionListener = new ActionListener() {
int waitCounter = 0;
@Override
public void actionPerformed(ActionEvent e) {
// When the angle reaches 360, set a wait for 100
// runs of the timer.
if (angle >= 360) {
angle = 0;
waitCounter = 100;
}
// If waiting, count down the time. When the wait
// counter is zero, do the actual work.
if (waitCounter > 0) {
waitCounter--;
} else {
angle++;
repaint();
}
}
};
// The timer itself runs every 10 milliseconds.
Timer timer = new Timer(10, actionListener);
timer.start();
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D gg = (Graphics2D) g;
gg.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
// Set the clipping arc to the current angle.
clip.setAngleExtent(angle);
gg.setClip(clip);
// Draw a full circle. It will be clipped to the arc set above.
gg.setColor(Color.BLACK);
gg.drawOval(40,40,100,100);
}
}
我使用了
gg.setStroke(新的BasicStroke(8f)
来夸大原始效果;很好地使用了剪辑区域。为什么要导入java.awt.Color
两次?