从一个
previous question
,我一直在寻找在Java中将活动呈现与文本字段相结合的最佳方法。我尝试了几个选项,使用BufferStrategy、VolatileImage或覆盖标准AWT中的update()和paint(),但最终使用了Swing。
我在这里发布了当前的状况,以防有人碰巧根据我的代码示例有了新的见解,也许其他正在开发类似应用程序的人可能会从我的发现中受益。
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在仅在必要时更新的背景缓冲区上渲染动画对象
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在渲染结果顶部使用文本字段
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下面是在stackoverflower的帮助下开发的演示应用程序的代码
trashgod
两个注意事项:
2) 将BuffereImage绘制到屏幕的效率在很大程度上取决于平台。Mac实现似乎不支持正确的硬件加速,这使得将背景图像重新绘制到输出窗口成为一项乏味的任务,当然这取决于窗口的大小。
1920 x 1100:5毫秒,35-40%
Windows XP操作系统:
1920 x 1100:0.05毫秒,0%
屏幕大小:绘制帧的平均时间,应用程序的CPU使用率。
据我所知,下面的代码是实现我的目标最有效的方法。任何新的见解,优化或测试结果是非常欢迎的!
当做,
马提斯
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.GridLayout;
import java.awt.Rectangle;
import java.awt.Transparency;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Timer;
public class SwingTest extends JPanel implements
ActionListener,
Runnable
{
private static final long serialVersionUID = 1L;
private BufferedImage backgroundBuffer;
private boolean repaintbackground = true;
private static final int initWidth = 640;
private static final int initHeight = 480;
private static final int radius = 25;
private final Timer t = new Timer(20, this);
private final Rectangle rect = new Rectangle();
private long totalTime = 0;
private int frames = 0;
private long avgTime = 0;
public static void main(String[] args) {
EventQueue.invokeLater(new SwingTest());
}
public SwingTest() {
super(true);
this.setPreferredSize(new Dimension(initWidth, initHeight));
this.setLayout(null);
this.setOpaque(false);
this.addMouseListener(new MouseHandler());
}
@Override
public void run() {
JFrame f = new JFrame("SwingTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.addComponentListener(new ResizeHandler());
/* This extra Panel with GridLayout is necessary to make sure
our content panel is properly resized with the window.*/
JPanel p = new JPanel(new GridLayout());
p.add(this);
f.add(p);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
createBuffer();
t.start();
}
@Override
public void actionPerformed(ActionEvent e) {
this.repaint();
}
@Override
protected void paintComponent(Graphics g) {
long start = System.nanoTime();
super.paintComponent(g);
if (backgroundBuffer == null) createBuffer();
if (repaintbackground) {
/* Repainting the background may require complex rendering operations,
so we don't want to do this every frame.*/
repaintBackground(backgroundBuffer);
repaintbackground = false;
}
/* Repainting the pre-rendered background buffer every frame
seems unavoidable. Previous attempts to keep track of the
invalidated area and repaint only that part of the background buffer
image have failed. */
g.drawImage(backgroundBuffer, 0, 0, null);
repaintBall(g, backgroundBuffer, this.getWidth(), this.getHeight());
repaintDrawTime(g, System.nanoTime() - start);
}
void repaintBackground(BufferedImage buffer) {
Graphics2D g = buffer.createGraphics();
int width = buffer.getWidth();
int height = buffer.getHeight();
g.clearRect(0, 0, width, height);
for (int i = 0; i < 100; i++) {
g.setColor(new Color(0, 128, 0, 100));
g.drawLine(width, height, (int)(Math.random() * (width - 1)), (int)(Math.random() * (height - 1)));
}
}
void repaintBall(Graphics g, BufferedImage backBuffer, int width, int height) {
double time = 2* Math.PI * (System.currentTimeMillis() % 3300) / 3300.;
rect.setRect((int)(Math.sin(time) * width/3 + width/2 - radius), (int)(Math.cos(time) * height/3 + height/2) - radius, radius * 2, radius * 2);
g.setColor(Color.BLUE);
g.fillOval(rect.x, rect.y, rect.width, rect.height);
}
void repaintDrawTime(Graphics g, long frameTime) {
if (frames == 32) {avgTime = totalTime/32; totalTime = 0; frames = 0;}
else {totalTime += frameTime; ++frames; }
g.setColor(Color.white);
String s = String.valueOf(avgTime / 1000000d + " ms");
g.drawString(s, 5, 16);
}
void createBuffer() {
int width = this.getWidth();
int height = this.getHeight();
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice gs = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gs.getDefaultConfiguration();
backgroundBuffer = gc.createCompatibleImage(width, height, Transparency.OPAQUE);
repaintbackground = true;
}
private class MouseHandler extends MouseAdapter {
@Override
public void mousePressed(MouseEvent e) {
super.mousePressed(e);
JTextField field = new JTextField("test");
Dimension d = field.getPreferredSize();
field.setBounds(e.getX(), e.getY(), d.width, d.height);
add(field);
}
}
private class ResizeHandler extends ComponentAdapter {
@Override
public void componentResized(ComponentEvent e) {
super.componentResized(e);
System.out.println("Resized to " + getWidth() + " x " + getHeight());
createBuffer();
}
}
}