java 不断移动的方块_java – 将一个方块从起点移动到以固定速度点击鼠标的位置...

遇到问题时,我倾向于回归基础知识,我该怎么做？

我知道我可以：

>计算两点之间的距离

>在给定的持续时间内将对象移动一长行.

所以我们知道：

>起点

>终点

由此我们可以计算出两点之间的距离.

double distance = Math.sqrt(

(startX - targetX) * (startX - targetX)

+ (startY - targetY) * (startY - targetY));

有了这个,我们可以根据所需的速度计算在两点之间行进所需的时间

time = distance / speed

速度是一个常数(在我的例子中为0.1,使其变小以使其变慢)

有了这些信息,我们知道我们必须走多长时间,我们可以根据开始时(点击鼠标时)和现在之间的差异来计算沿线/路径的进度.

假设startTime是我们开始移动的时间,runningTime是我们需要运行的时间以保持恒定的速度

然后,我们可以使用类似……

long duration = System.currentTimeMillis() - startTime;

double progress = duration / runTime;

由此我们可以根据当前持续时间计算沿线的位置……

double x = (int) (startX + ((targetX - startX) * progress));

double y = (int) (startY + ((targetY - startY) * progress));

作为概念的证明.对不起,您没有提到您正在使用的框架;)

import java.awt.Color;

import java.awt.Dimension;

import java.awt.EventQueue;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Rectangle;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.geom.Line2D;

import java.awt.geom.Rectangle2D;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.Timer;

import javax.swing.UIManager;

import javax.swing.UnsupportedLookAndFeelException;

public class TestMove {

public static void main(String[] args) {

new TestMove();

}

public TestMove() {

EventQueue.invokeLater(new Runnable() {

@Override

public void run() {

try {

UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {

ex.printStackTrace();

}

JFrame frame = new JFrame("Testing");

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.add(new TestPane());

frame.pack();

frame.setLocationRelativeTo(null);

frame.setVisible(true);

}

});

}

public class TestPane extends JPanel {

private Rectangle champion;

private Line2D path;

private double speed = 0.1;

private Timer timer;

private Long startTime;

private double targetX, targetY;

private double startX, startY;

private double runTime;

public TestPane() {

champion = new Rectangle(95, 95, 10, 10);

addMouseListener(new MouseAdapter() {

@Override

public void mouseClicked(MouseEvent e) {

timer.stop();

calculateChampionMovement(e.getX(), e.getY(), champion);

startTime = System.currentTimeMillis();

timer.start();

}

});

timer = new Timer(40, new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

if (targetX == champion.getCenterX() && targetY == champion.getCenterY()) {

System.out.println("Stopped as same");

timer.stop();

}

long duration = System.currentTimeMillis() - startTime;

double progress = duration / runTime;

if (progress >= 1.0) {

System.out.println("Stopped out of time");

progress = 1.0;

timer.stop();

}

double x = (int) (startX + ((targetX - startX) * progress));

double y = (int) (startY + ((targetY - startY) * progress));

// x/y are the center points, need to adjust them so the shape

// moves about the center point

champion.setRect(x - 5, y - 5, 10, 10);

repaint();

}

});

}

@Override

public Dimension getPreferredSize() {

return new Dimension(200, 200);

}

@Override

protected void paintComponent(Graphics g) {

super.paintComponent(g);

Graphics2D g2d = (Graphics2D) g.create();

g2d.draw(champion);

if (path != null) {

g2d.setColor(Color.RED);

g2d.draw(path);

}

g2d.dispose();

}

public void calculateChampionMovement(double x, double y, Rectangle champion) {

if (x != champion.getCenterX() || y != champion.getCenterY()) {

targetX = x;

targetY = y;

startX = champion.getCenterX();

startY = champion.getCenterY();

path = new Line2D.Double(

champion.getCenterX(),

champion.getCenterY(),

x, y);

double distance = Math.sqrt(

(startX - targetX) * (startX - targetX)

+ (startY - targetY) * (startY - targetY));

runTime = distance / (double)speed;

}

}

}

}