如何在java中进行精灵跳转？

我有一个用于向左，向右，向上和向下移动的精灵的KeyEvents。 我只是搞乱了，正在考虑另一个我希望精灵跳跃的项目。 它不一定非常现实，因为我刚刚开始。 我所拥有的是当按下空格键时，它将导致精灵跳跃，让我们说“dy = -3”。 那么我有KeyRevent的KeyEvent，它会掉落，“dy = -2”。 这不起作用，因为精灵只是继续下降…有人能发光吗？

整个代码：包冲突;

import java.awt.Image; import java.awt.Rectangle; import java.awt.event.KeyEvent; import java.util.ArrayList; import javax.swing.ImageIcon; public class Craft { private String craft = "pelican.png"; private int dx; private int dy; private int x; private int y; private int width; private int height; private boolean visible; private Image image; private ArrayList missiles; public Craft() { ImageIcon ii = new ImageIcon(this.getClass().getResource(craft)); image = ii.getImage(); width = image.getWidth(null); height = image.getHeight(null); missiles = new ArrayList(); visible = true; x = 100; y = 300; } public void move() { x += dx; y += dy; if (x < 1) { x = 1; } if (y < 1) { y = 1; } } public int getX() { return x; } public int getY() { return y; } public Image getImage() { return image; } public ArrayList getMissiles() { return missiles; } public void setVisible(boolean visible) { this.visible = visible; } public boolean isVisible() { return visible; } public Rectangle getBounds() { return new Rectangle(x, y, width, height); } public void keyPressed(KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_SPACE) { } if (key == KeyEvent.VK_V){ dx = 6; } if (key == KeyEvent.VK_LEFT) { dx = -1; } if (key == KeyEvent.VK_RIGHT) { dx = 2; } if (key == KeyEvent.VK_UP) { dy = -1; } if (key == KeyEvent.VK_DOWN) { dy = 1; } } public void fire() { missiles.add(new Missile(x + width, y + height/2)); } public void keyReleased(KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_LEFT) { dx = 0; } if (key == KeyEvent.VK_SPACE) { } if (key == KeyEvent.VK_RIGHT) { dx = 0; } if (key == KeyEvent.VK_UP) { dy = 0; } if (key == KeyEvent.VK_DOWN) { dy = 0; } } } 

您可能已经注意到我是Java的新手以及游戏编程。 我想要的只是精灵上升，然后回来。 如果有帮助，它将始终保持静止。 精灵只是继续跳跃，直到他被一个即将到来的障碍击中。 我知道有其他动作的代码，但是一旦我开始下一个精灵就会删除它们。

Answer 1

这是基本概念。 您的实施将根据引擎的实施而变化。

基本思想是玩家有一个垂直三角洲，它随着时间的推移而发生重力变化。 这会影响精灵的垂直速度。

这个实现也有一个重新绑定的delta，它允许sprite重新绑定而不是突然“停止”。 通过重新结合的降解实现重新结合，这降低了每个重新结合的重新结合的量。

这模拟了一个游戏角色，所以你需要点击Space才能让它弹跳……

 import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import javax.swing.AbstractAction; import javax.swing.ActionMap; import javax.swing.InputMap; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.KeyStroke; import javax.swing.Timer; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; public class JumpingSprite { public static void main(String[] args) { new JumpingSprite(); } public JumpingSprite() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { } JFrame frame = new JFrame("Test"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); frame.add(new TestPane()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public static class TestPane extends JPanel { protected static final int SPRITE_HEIGHT = 10; protected static final int SPRITE_WIDTH = 10; private float vDelta; // The vertical detla... private float rbDelta; // Rebound delta... private float rbDegDelta; // The amount the rebound is degradation... private int yPos; // The vertical position... private float gDelta; // Gravity, how much the vDelta will be reduced by over time... private Timer engine; private boolean bounce = false; public TestPane() { yPos = getPreferredSize().height - SPRITE_HEIGHT; vDelta = 0; gDelta = 0.25f; // This is how much the re-bound will degrade on each cycle... rbDegDelta = 2.5f; InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW); ActionMap am = getActionMap(); im.put(KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0), "jump"); am.put("jump", new AbstractAction() { @Override public void actionPerformed(ActionEvent e) { // Can only bound when we're actually on the ground... // You might want to add fudge factor here so that the // sprite can be within a given number of pixels in order to // jump again... if (yPos + SPRITE_HEIGHT == getHeight()) { vDelta = -8; rbDelta = vDelta; bounce = true; } } }); engine = new Timer(40, new ActionListener() { @Override public void actionPerformed(ActionEvent e) { int height = getHeight(); // No point if we've not been sized... if (height > 0) { // Are we bouncing... if (bounce) { // Add the vDelta to the yPos // vDelta may be postive or negative, allowing // for both up and down movement... yPos += vDelta; // Add the gravity to the vDelta, this will slow down // the upward movement and speed up the downward movement... // You may wish to place a max speed to this vDelta += gDelta; // If the sprite is not on the ground... if (yPos + SPRITE_HEIGHT >= height) { // Seat the sprite on the ground yPos = height - SPRITE_HEIGHT; // If the re-bound delta is 0 or more then we've stopped // bouncing... if (rbDelta >= 0) { // Stop bouncing... bounce = false; } else { // Add the re-bound degregation delta to the re-bound delta rbDelta += rbDegDelta; // Set the vDelta... vDelta = rbDelta; } } } } repaint(); } }); engine.start(); } @Override public Dimension getPreferredSize() { return new Dimension(200, 200); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g.create(); int width = getWidth() - 1; int xPos = (width - SPRITE_WIDTH) / 2; g2d.drawOval(xPos, yPos, SPRITE_WIDTH, SPRITE_HEIGHT); g2d.dispose(); } } } 

Answer 2

好吧，我可以想到一个方法。 它涉及一些复杂的数学（抛物线）。 所以我将提供一个非常简单的答案。

 int y = 0; 

并在测试空格键的方法中……

 if (y !< 1){ if (y < 30){ y += 1; } if (y > 30){ y -= 1; } } 

我还没有测试它，但它应该在理论上工作….但它不会动画任何东西，这个代码只会采取精灵Y值并使其上升。 这只是可以存在的最简单的跳跃方法….