I'm trying to make it print out "Game over" when the Green Square(Cuboid) runs over/into the blue(CuboidKiller) one.
GAME class:
package plugin.dev.wristz;
import java.awt.Graphics;
import java.awt.Image;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.JFrame;
public class Game extends JFrame {
private static final long serialVersionUID = 294623570092988970L;
public static ArrayList<CuboidKiller> killers;
public static int h = 1024, w = 768;
public static Game game;
public static Graphics graphics, g2;
public static Image image;
public static Cuboid cuboid;
public Game(String title) {
setTitle(title);
setSize(1024, 768);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setResizable(true);
setVisible(true);
setLocationRelativeTo(null);
addKeyListener(new KeyHandler(cuboid));
g2 = getGraphics();
paint(g2);
}
public static void main(String[] args) {
cuboid = new Cuboid();
Thread cubi = new Thread(cuboid);
cubi.start();
killers = new ArrayList<CuboidKiller>();
CuboidKiller a = new CuboidKiller(new Random().nextInt(h), new Random().nextInt(w), new Random().nextInt(50) + 20);
killers.add(a);
game = new Game("Killer Cuboids");
}
#Override
public void paint(Graphics g) {
image = createImage(getWidth(), getHeight());
graphics = image.getGraphics();
paintComponent(graphics);
g.drawImage(image, 0, 0, this);
}
public void paintComponent(Graphics g) {
checkGameOver();
cuboid.draw(g);
for (CuboidKiller killer : killers)
killer.draw(g);
repaint();
}
public void checkGameOver() {
for (CuboidKiller killer : killers)
if (killer.isTouching(cuboid))
System.out.println("Game over!");
}
public int getH() {
return h;
}
public void setH(int wh) {
h = wh;
}
public int getW() {
return w;
}
public void setW(int ww) {
w = ww;
}
}
Cuboid class:
package plugin.dev.wristz;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
#SuppressWarnings("static-access")
public class Cuboid implements Runnable {
private int x, y, xDirection, zDirection;
public Cuboid() {
this.x = 799;
this.y = 755;
}
public void draw(Graphics g) {
g.setColor(Color.GREEN);
g.fillRect(x, y, 25, 25);
}
public void move() {
x += xDirection;
y += zDirection;
if (x <= 10)
x = 0 + 10;
if (y <= 35)
y = 0 + 35;
if (x >= 1024 - 35)
x = 1024 - 35;
if (y >= 768 - 35)
y = 768 - 35;
}
public void keyPressed(KeyEvent ev) {
int keyCode = ev.getKeyCode();
if (keyCode == ev.VK_LEFT) {
setXDirection(-5);
}
if (keyCode == ev.VK_RIGHT) {
setXDirection(5);
}
if (keyCode == ev.VK_UP) {
setZDirection(-5);
}
if (keyCode == ev.VK_DOWN) {
setZDirection(5);
}
}
public void keyReleased(KeyEvent ev) {
int keyCode = ev.getKeyCode();
if (keyCode == ev.VK_LEFT) {
setXDirection(0);
}
if (keyCode == ev.VK_RIGHT) {
setXDirection(0);
}
if (keyCode == ev.VK_UP) {
setZDirection(0);
}
if (keyCode == ev.VK_DOWN) {
setZDirection(0);
}
}
#Override
public void run() {
try {
while (true) {
move();
Thread.sleep(5);
}
} catch (Exception e) {
System.err.println(e.getMessage());
}
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public int getXDirection() {
return xDirection;
}
public void setXDirection(int xDirection) {
this.xDirection = xDirection;
}
public int getZ() {
return y;
}
public void setZ(int z) {
this.y = z;
}
public int getZDirection() {
return zDirection;
}
public void setZDirection(int zDirection) {
this.zDirection = zDirection;
}
}
Cuboid Killer:
package plugin.dev.wristz;
import java.awt.Color;
import java.awt.Graphics;
import java.util.HashMap;
public class CuboidKiller {
private int x, y, radius;
private HashMap<Integer, Integer> points;
public CuboidKiller(int x, int y, int radius) {
this.points = new HashMap<Integer, Integer>();
setPoints();
this.x = x;
this.y = y;
this.radius = radius;
}
public void draw(Graphics g) {
g.setColor(Color.blue);
g.fillRect(x, y, radius, radius);
}
public void setPoints() {
this.points.put(x, y);
this.points.put(x + radius, y);
this.points.put(x + radius, y - radius);
this.points.put(x, y - radius);
}
public boolean isTouching(Cuboid cuboid) {
boolean result = true;
//int a = cuboid.getX(), b = cuboid.getZ();
result = true;
return result;
}
public int getRadius() {
return radius;
}
public void setRadius(int radius) {
this.radius = radius;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public HashMap<Integer, Integer> getPoints() {
return points;
}
public void setPoints(HashMap<Integer, Integer> points) {
this.points = points;
}
}
Well, there are two approaches. Either you write it yourself, or you just use what Java 8 provides.
This guy has a very nice explanation on how to detect collision between two rectangles: Java check if two rectangles overlap at any point
But if I were the one writing it, I would just have both classes contain a Rectangle object (http://docs.oracle.com/javase/8/docs/api/java/awt/Rectangle.html), and just call the intersects() function provided by Rectangle. :-)
Related
I'm trying to create Circles in JFrame using JComponent. Here's what I'm trying to achieve:
And here's what's happening with my code:
I have no idea what's causing this problem. Here's my code:
CircleViewer.java
import javax.swing.JFrame;
import java.awt.event.*;
public class CircleViewer
{
public static void main(String[] args)
{
final CirclePanel panel = new CirclePanel();
class MousePressListener implements MouseListener, MouseMotionListener
{
public void mouseClicked(MouseEvent event) { }
public void mouseEntered(MouseEvent event) { }
public void mouseExited(MouseEvent event) { }
public void mouseWheelMoved(MouseWheelEvent event) { }
public void mouseMoved(MouseEvent event) { }
public void mousePressed(MouseEvent event)
{
var x = event.getX();
var y = event.getY();
panel.addCircle(x, y);
}
public void mouseDragged(MouseEvent event)
{
var x = event.getX();
var y = event.getY();
panel.moveTo(x, y);
}
public void mouseReleased(MouseEvent event)
{
panel.finalMove();
}
}
MousePressListener listener = new MousePressListener();
panel.addMouseListener(listener);
panel.addMouseMotionListener(listener);
JFrame frame = new JFrame("Circle Shapes");
frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel);
frame.setVisible(true);
}
private static final int FRAME_WIDTH = 700;
private static final int FRAME_HEIGHT = 500;
}
CirclePanel.java
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JComponent;
import java.util.ArrayList;
import java.awt.Color;
import java.lang.Math;
import java.awt.BasicStroke;
import java.awt.Stroke;
public class CirclePanel extends JComponent
{
private int lineX;
private int lineY;
private boolean isDraged;
private ArrayList<Circle> circleList;
private BasicStroke dashLine;
public CirclePanel()
{
this.circleList = new ArrayList<Circle>();
this.isDraged = false;
this.lineX = 0;
this.lineY = 0;
this.dashLine = new BasicStroke(1, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL, 0, new float[]{6}, 0);
}
public void addCircle(int x, int y)
{
lineX = x;
lineY = y;
isDraged = true;
circleList.add(new Circle(x, y, 0, Color.RED));
repaint();
}
public void moveTo(int x, int y)
{
var circleTemp = circleList.get(circleList.size() - 1);
isDraged = true;
var tempR = (int)Math.sqrt(Math.pow(x - circleTemp.get(0), 2) + Math.pow(y - circleTemp.get(1), 2));
System.out.println(tempR);
var tempX = circleTemp.get(0) - (tempR / 2);
var tempY = circleTemp.get(1) - (tempR / 2);
circleList.get(circleList.size() - 1).setCords(tempX, tempY, tempR);
lineX = x;
lineY = y;
repaint();
}
public void finalMove()
{
isDraged = false;
circleList.get(circleList.size() - 1).setColor(Color.BLUE);
repaint();
}
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D)g;
Stroke defaultStroke;
defaultStroke = g2.getStroke();
if (!circleList.isEmpty())
{
if (isDraged)
{
g2.setColor(Color.RED);
g2.setStroke(dashLine);
g2.drawLine(circleList.get(circleList.size() - 1).get(0), circleList.get(circleList.size() - 1).get(1), lineX, lineY);
}
for (Circle circle : circleList)
{
g2.setStroke(defaultStroke);
circle.draw(g2);
isDraged = false; //this is prob reduntant
}
}
}
}
And finally, Circle.java
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.geom.Ellipse2D;
public class Circle
{
private int x;
private int y;
private int radius;
private Color color;
public Circle(int x, int y, int radius, Color color)
{
this.x = x;
this.y = y;
this.radius = radius;
this.color = color;
}
public int get(int option)
{
switch (option)
{
case 0:
return this.x;
case 1:
return this.y;
case 2:
return this.radius;
}
return 0;
}
public Color get()
{
return this.color;
}
public void setCords(int x, int y, int r)
{
this.x = x;
this.y = y;
this.radius = r;
}
public void set(int option, int value)
{
switch (option)
{
case 0: //set x
this.x = value;
break;
case 1:
this.y = value;
break;
case 2:
radius = value;
break;
}
}
public void setColor(Color color)
{
this.color = color;
}
public void draw(Graphics2D g2)
{
g2.setColor(color);
g2.draw(new Ellipse2D.Double(x, y, radius, radius));
}
}
Rather than finding the specific problem in you code, I just decided to make a cleaner implementation. Using this circle class
class Circle {
final int x;
final int y;
int radius;
public Circle(int x, int y, int radius) {
this.x = x;
this.y = y;
this.radius = radius;
}
}
You can implement CirclePanel like this:
public class CirclePanel extends JPanel {
private static final Stroke DASHED = new BasicStroke(1,
BasicStroke.CAP_BUTT,
BasicStroke.JOIN_BEVEL,
0, new float[]{6}, 0);
public Color oldCircleColor = Color.BLUE;
public Color newCircleColor = Color.RED;
public Color backgroundColor = Color.LIGHT_GRAY;
private final List<Circle> oldCircles = new ArrayList<>();
private Circle newCircle = null;
private int mouseX = 0;
private int mouseY = 0;
private class MouseHelper implements MouseListener, MouseMotionListener {
#Override public void mouseMoved(MouseEvent e) {}
#Override public void mouseClicked(MouseEvent e) {}
#Override public void mousePressed(MouseEvent e) {}
#Override public void mouseEntered(MouseEvent e) {}
#Override public void mouseExited(MouseEvent e) {}
#Override
public void mouseDragged(MouseEvent e) {
mouseX = e.getX();
mouseY = e.getY();
if (newCircle == null) {
newCircle = new Circle(mouseX, mouseY, 0);
} else {
int dX = newCircle.x - mouseX;
int dY = newCircle.y - mouseY;
newCircle.radius = (int) Math.sqrt(dX*dX + dY*dY);
}
repaint();
}
#Override
public void mouseReleased(MouseEvent e) {
if (newCircle != null) {
oldCircles.add(newCircle);
newCircle = null;
repaint();
}
}
}
public CirclePanel() {
MouseHelper helper = new MouseHelper();
addMouseListener(helper);
addMouseMotionListener(helper);
setPreferredSize(new Dimension(400, 400));
}
#Override
public void paint(Graphics g) {
g.setColor(backgroundColor);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(oldCircleColor);
for (Circle c : oldCircles) {
drawCircle(g, c);
}
Circle c = newCircle;
if (c != null) {
g.setColor(newCircleColor);
drawCircle(g, c);
Graphics2D g2 = (Graphics2D) g.create();
g2.setStroke(DASHED);
g2.drawLine(c.x, c.y, mouseX, mouseY);
g2.dispose();
}
}
private void drawCircle(Graphics g, Circle c) {
// note: drawOval takes top-left corner and diameter, NOT center and radius
g.drawOval(c.x - c.radius, c.y - c.radius, c.radius * 2, c.radius * 2);
}
}
And test to see that it works
public static void main(String[] args) {
JFrame frame = new JFrame();
CirclePanel panel = new CirclePanel();
frame.add(panel);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
Like #SirLenz0rlot mentioned in the comments there is a bug in your moveTo method. The problem is the call circleList.get(circleList.size() - 1).setCords(tempX, tempY, tempR); which is setting the position of the circle to tempX, tempY, but you probably only want to set the radius of the circle, while the coords are not changed.
Changing the moveTo method to the code below should help:
public void moveTo(int x, int y)
{
var circleTemp = circleList.get(circleList.size() - 1);
isDraged = true;
var tempR = (int)Math.sqrt(Math.pow(x - circleTemp.get(0), 2) + Math.pow(y - circleTemp.get(1), 2));
System.out.println(tempR);
var tempX = circleTemp.get(0) - (tempR / 2);
var tempY = circleTemp.get(1) - (tempR / 2);
//EDITED HERE
circleList.get(circleList.size() - 1).setCords(circleTemp.get(0), circleTemp.get(1), tempR);//using getX() and getY() on your circle would be easier to understand here, but this should also work...
lineX = x;
lineY = y;
repaint();
}
For some reason your circleTemp.get(0) and (1) doesn't give you the (x,y) coordinates
circleTemp.get(0)
What you should do is save the circle's (x,y) coordinates, and use them in the moveTo method.
Correct Change
And in the end for the draw line, you should again, use the saved (x,y) coordinates and the new coordinated of the mouse. (not the circleList.size() -1).get(0) - Line 67)
(Ex. I added the drawLineX and drawLineY)
I am working on a 2D platformer in Java for an assignment. The assignment specifies I must use an abstract shape class to draw shapes. The problem I am having is getting my collision detection to work with multiple Rectangle Objects which I am using as platforms - I store these in a list. At the moment my collision detection will move my player regardless of which platform I have collided with, so if I collide with a platform from the right it will move me to the top of that platform because it's still checking another platform below me, and will assume I've hit that, therefore moving me to the top of the platform. I was wondering how I can change this so that my collision detection also detects which platform I have collided with and collide relative to that platform (as opposed to every platform).
Here's what is currently happening:
Expected Output:
My player should stop where it is when colliding with platforms.
My App class:
package A2;
import javax.swing.*;
import java.awt.*;
import java.util.ArrayList;
public class App extends JFrame {
public App() {
final Player player = new Player(200, 100);
final ArrayList<Rectangle> platforms = new ArrayList<>();
platforms.add(new Rectangle(100, 500, 400 ,10));
platforms.add(new Rectangle(500, 100, 10 ,400));
JPanel mainPanel = new JPanel() {
public void paintComponent(Graphics g) {
super.paintComponent(g);
player.draw(g);
for(Rectangle r : platforms){
r.draw(g);
}
}
};
mainPanel.addKeyListener(new InputControl(this, player, platforms));
mainPanel.setFocusable(true);
add(mainPanel);
setLayout(new GridLayout());
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setSize(600, 600);
}
public static void main(String[] args) {
App app = new App();
app.setVisible(true);
}
}
abstract class Shape {
public void draw(Graphics g) { }
}
My input handling class:
package A2;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import static java.awt.event.KeyEvent.*;
public class InputControl implements ActionListener, KeyListener {
App app;
Player player;
Timer time = new Timer(5, this);
ArrayList<Rectangle> platforms;
ArrayList<Integer> keyList = new ArrayList<>();
boolean keyReleased = false;
boolean keyPressed = false;
boolean[] keyUp = new boolean[256];
boolean[] keyDown = new boolean[256];
boolean topCollision = false;
boolean rightCollision = false;
boolean leftCollision = false;
boolean botCollision = false;
boolean onGround = false;
private static final double GRAVITY = 2;
private static final int MAX_FALL_SPEED = 5;
double Xoverlap = 0;
double Yoverlap = 0;
boolean collision = false;
public InputControl(App app, Player player, ArrayList<Rectangle> platforms) {
this.app = app;
this.player = player;
this.platforms = platforms;
time.start();
}
public void gravity(){
if(player.yVelocity > MAX_FALL_SPEED){
player.yVelocity = MAX_FALL_SPEED;
}
player.yVelocity += GRAVITY;
}
public void momentum(){}
public void actionPerformed(ActionEvent e) {
Rectangle2D offset = player.getOffsetBounds();
for(int i = 0; i < platforms.size(); i++) {
Rectangle r = platforms.get(i);
//If collision
if (offset.intersects(r.obj.getBounds2D())) {
//Collision on Y axis
if (offset.getX() + offset.getWidth() > r.obj.getX() &&
offset.getX() < r.obj.getX() + r.obj.getWidth() &&
offset.getY() + offset.getHeight() > r.obj.getY() &&
offset.getY() + player.yVelocity < r.obj.getY() + r.obj.getHeight()) {
player.y -= (offset.getY() + offset.getHeight()) - r.obj.getY();
}
//Collision on X axis
if (offset.getX() + offset.getWidth() + player.xVelocity > r.obj.getX() &&
offset.getX() + player.xVelocity < r.obj.getX() + r.obj.getWidth() &&
offset.getY() + offset.getHeight() > r.obj.getY() &&
offset.getY() < r.obj.getY() + r.obj.getHeight()) {
player.x -= (offset.getX() + offset.getHeight()) - r.obj.getX();
}
}
else {
player.x += player.xVelocity;
player.y += player.yVelocity;
}
}
player.x += player.xVelocity;
player.y += player.yVelocity;
app.repaint();
}
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() >= 0 && e.getKeyCode() < 256) {
keyDown[e.getKeyCode()] = true;
keyUp[e.getKeyCode()] = false;
keyPressed = true;
keyReleased = false;
}
if (keyDown[VK_UP]) {
player.yVelocity = -1;
}
if (keyDown[VK_RIGHT]){
player.xVelocity = 1;
}
if (keyDown[VK_LEFT]) {
player.xVelocity = -1;
}
if (keyDown[VK_DOWN]) {
player.yVelocity = 1;
}
}
public void keyReleased(KeyEvent e) {
if(e.getKeyCode() >= 0 && e.getKeyCode() < 256) {
keyDown[e.getKeyCode()] = false;
keyUp[e.getKeyCode()] = true;
keyPressed = false;
keyReleased = true;
}
if(keyUp[VK_RIGHT] || keyUp[VK_LEFT]){
player.xVelocity = 0;
}
if(keyUp[VK_UP]){
player.yVelocity = 0;
}
}
public void keyTyped(KeyEvent e) { }
}
My Player class:
package A2;
import java.awt.*;
import java.awt.geom.Rectangle2D;
public class Player extends Shape {
public double xVelocity;
public double yVelocity;
public double x;
public double y;
public double width = 60;
public double height = 60;
public double weight = 5;
public Rectangle2D obj;
public Player(double x, double y) {
this.x = x;
this.y = y;
obj = new Rectangle2D.Double(x, y, width, height);
}
public Rectangle2D getOffsetBounds(){
return new Rectangle2D.Double( x, y, width, height);
}
public void draw(Graphics g) {
Color c =new Color(1f,0f,0f,0.2f );
obj = new Rectangle2D.Double(x, y, width, height);
g.setColor(Color.BLACK);
Graphics2D g2 = (Graphics2D)g;
g2.fill(obj);
g.drawString("(" + String.valueOf(x) + ", " + String.valueOf(y) + ")", 10, 20);
g.drawString("X Speed: " + String.valueOf(xVelocity) + " Y Speed: " + String.valueOf(yVelocity) + ")", 10, 35);
g.setColor(c);
}
}
My Rectangle class:
package A2;
import java.awt.*;
import java.awt.geom.Rectangle2D;
public class Rectangle extends Shape {
public double width;
public double height;
public double x;
public double y;
boolean hasCollided = false;
public Rectangle2D obj;
public Rectangle(double x, double y, double width, double height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
obj = new Rectangle2D.Double(x, y, width, height);
}
public void draw(Graphics g) {
g.setColor(Color.ORANGE);
Graphics2D g2 = (Graphics2D)g;
g2.fill(obj);
}
}
First, define ColorRectangle class that extends Shape and provide logic for drawing:
// extends java.awt.Shape
abstract class ColorRectangle extends Rectangle {
private static final long serialVersionUID = -3626687047605407698L;
private final Color color;
protected ColorRectangle(int x, int y, int width, int height, Color color) {
super(x, y, width, height);
this.color = color;
}
public void draw(Graphics2D g) {
g.setColor(color);
g.fillRect(x, y, width, height);
}
}
Second, define separate class for represent Player and Platform:
public final class Player extends ColorRectangle {
private static final long serialVersionUID = -3909362955417024742L;
public Player(int width, int height, Color color) {
super(0, 0, width, height, color);
}
}
public final class Platform extends ColorRectangle {
private static final long serialVersionUID = 6602359551348037628L;
public Platform(int x, int y, int width, int height, Color color) {
super(x, y, width, height, color);
}
public boolean intersects(Player player, int offsX, int offsY) {
return intersects(player.x + offsX, player.y + offsY, player.width, player.height);
}
}
Third, define class that contains logic of demo application. Actually, you could split logic for demo and logic for board (including actiona and key listeners), but these classes are very simple, so in given case, no need to split it.
public class CollisionDetectionDemo extends JFrame {
public CollisionDetectionDemo() {
setLayout(new GridLayout());
add(new MainPanel());
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setSize(600, 600);
}
private static class MainPanel extends JPanel implements ActionListener, KeyListener {
private static final long serialVersionUID = 8771401446680969350L;
private static final int OFFS = 5;
private final Player player = new Player(60, 60, Color.BLACK);
private final List<Platform> platforms = Arrays.asList(
new Platform(100, 500, 400, 10, Color.ORANGE),
new Platform(500, 100, 10, 410, Color.RED),
new Platform(150, 300, 100, 10, Color.BLUE),
new Platform(150, 100, 100, 10, Color.GREEN));
private MainPanel() {
player.x = 200;
player.y = 200;
new Timer(5, this).start();
setFocusable(true);
addKeyListener(this);
}
private void drawPlayerPosition(Graphics g) {
g.setColor(Color.BLACK);
g.drawString(String.format("(%d, %d)", player.x, player.y), 10, 20);
}
private void movePlayer(int offsX, int offsY) {
if (!intersects(player, offsX, offsY)) {
player.x += offsX;
player.y += offsY;
}
}
private boolean intersects(Player player, int offsX, int offsY) {
for (Platform platform : platforms)
if (platform.intersects(player, offsX, offsY))
return true;
return false;
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Color color = g.getColor();
drawPlayerPosition(g);
player.draw((Graphics2D)g);
platforms.forEach(platform -> platform.draw((Graphics2D)g));
g.setColor(color);
}
#Override
public void actionPerformed(ActionEvent event) {
repaint();
}
#Override
public void keyTyped(KeyEvent event) {
}
#Override
public void keyPressed(KeyEvent event) {
if (event.getKeyCode() == VK_UP)
movePlayer(0, -OFFS);
else if (event.getKeyCode() == VK_DOWN)
movePlayer(0, OFFS);
else if (event.getKeyCode() == VK_LEFT)
movePlayer(-OFFS, 0);
else if (event.getKeyCode() == VK_RIGHT)
movePlayer(OFFS, 0);
}
#Override
public void keyReleased(KeyEvent event) {
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> new CollisionDetectionDemo().setVisible(true));
}
}
I am having a hard time trying to figure out why the paddle is flickering when I try to draw it. I know that I could use JFrame, but I am using awt for a specific reason. Any help would be appreciated!
import java.applet.Applet;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.Color;
public class Pong extends Applet implements Runnable,KeyListener{
//applet height and width
final int WIDTH = 700;
final int HEIGHT = 500;
Thread thread;
HumanPaddle p1;
//initialize the applet
public void init(){
this.resize(WIDTH, HEIGHT);
this.addKeyListener(this);
p1 = new HumanPaddle(1);
thread = new Thread(this);
thread.start();
}
//paints the applet
public void paint(Graphics g){
g.setColor(Color.black);
g.fillRect(0,0,WIDTH,HEIGHT);
p1.draw(g);
}
//continually updated within the program
public void update(Graphics g){
paint(g);
}
public void run() {
//infinite loop with a error try and catch
for(;;){
p1.move();
repaint();
try {
Thread.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_UP){
p1.setUpAccel(true);
}
else if(e.getKeyCode() == KeyEvent.VK_DOWN){
p1.setDownAccel(true);
}
}
public void keyReleased(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_UP){
p1.setUpAccel(false);
}
else if(e.getKeyCode() == KeyEvent.VK_DOWN){
p1.setDownAccel(false);
}
}
public void keyTyped(KeyEvent arg0) {
}
}
and the HumanPaddle class is:
import java.awt.Color;
import java.awt.Graphics;
public class HumanPaddle implements Paddle{
//declare variables
double y;
double yVel;
boolean upAccel;
boolean downAccel;
int player;
int x;
final double GRAVITY = 0.94;
public HumanPaddle(int player){
upAccel = false;
downAccel = false;
y = 210;
yVel = 0;
if(player == 1)
x = 20;
else
x = 660;
}
public void draw(Graphics g) {
g.setColor(Color.white);
g.fillRect(x, (int)y, 20, 80);
}
public void move() {
if(upAccel){
yVel -= 2;
}
else if(downAccel){
yVel += 2;
}
else if(!upAccel && !downAccel){
yVel *= GRAVITY;
}
y += yVel;
}
//setters
public void setY(double y){
this.y = y;
}
public void setYVel(double yVel){
this.yVel = yVel;
}
public void setUpAccel(boolean upAccel){
this.upAccel = upAccel;
}
public void setDownAccel(boolean downAccel){
this.downAccel = downAccel;
}
public void setPlayer(int player){
this.player = player;
}
public void setX(int x){
this.x = x;
}
//getters
public int getY(){
return (int)y;
}
public double getYVel(){
return yVel;
}
public boolean getUpAccel(){
return upAccel;
}
public boolean getDownAccel(){
return downAccel;
}
public int getPlayer(){
return player;
}
public int getX(){
return x;
}
}
If you are having this problem, the way I solved it was that I added repaint(), which calls the update method in the paint method. It has to be after when you draw in order so that the recursive loop won't leave that part out. I hope I explained that right, kinda a newby programmer!
I am trying to write a game in which a character moves around and jumps from block to block in order to get to the end. But the problem I'm facing is that my KeyPressed method won't run. I've tried putting a System.out.println("Hi"); in the method to see if it even starts running. But the "Hi" never showed up. This is my code.
import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class Driver extends Applet implements KeyListener
{
private int X = 0;
private int Y = 250;
private int sizeX = 25;
private int sizeY = 25;
private boolean start=false;
public int getX()
{
return X;
}
public void setX(int x)
{
X = x;
}
public int getY()
{
return Y;
}
public void setY(int y)
{
Y = y;
}
public int getsizeY()
{
return sizeY;
}
public void setsizeY(int sizey)
{
sizeY = sizey;
}
public int getsizeX()
{
return sizeX;
}
public void setsizeX(int sizex)
{
sizeX = sizex;
}
public void init()
{
this.addKeyListener(this);
setSize(300, 300);
setFocusable(false);
requestFocus();
}
public void paint(Graphics g)
{
init();
map map1 = new map();
g.setColor(Color.WHITE);
g.fillRect(0, 0, 300, 300);
g.setColor(Color.black);
map1.paint(g);
g.fillRect(X, Y, sizeX, sizeY);
start=true;
}
public void keyTyped(KeyEvent e)
{
}
public void keyReleased(KeyEvent e)
{
}
public void keyPressed(KeyEvent e)
{
if(start)
{
System.out.println("Hi");
if(e.getKeyChar() == 'w')
{
System.out.println("Hi");
setY(getY()-1);
}
if(e.getKeyChar() == 'd')
{
setX(getX()+1);
}
if(e.getKeyChar() == 'a')
{
setX(getX()-1);
}
if(e.getKeyChar() == 's')
{
setY(getY()+1);
}
repaint();
}
}
}
I am still learning how to code so please don't be mean, but if you could help that would be great!
I'm trying to create a rectangle that can freely move around the screen whilst also rotating so that it faces a circle or certain point.
My current state makes the object move in a very bizarre fashion and can't seem to fix it.
import javax.swing.JFrame;
public class Start {
public static void main(String[] args) {
JFrame f = new JFrame();
f.setTitle("Minigame");
f.setContentPane(new Panel());
f.setSize(1000, 1000);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Panel extends JPanel implements ActionListener, KeyListener{
private Timer timer;
private Graphics2D g2d;
private Planet planet;
private Player player;
private double rotation=0;
private int dx=0;
private int dy=0;
public Panel(){
setFocusable(true);
requestFocus();
planet = new Planet(100,100,100);
player = new Player(200,200,20,50);
}
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
g2d=(Graphics2D)g;
g2d.fillOval(planet.getX(), planet.getY(), planet.getRadius(), planet.getRadius());
g2d.setColor(Color.BLUE);
g2d.rotate(rotation,planet.centerX(),planet.centerY());
g2d.fillRect(player.getX(), player.getY(), player.getWidth(),player.getHeight());
g2d.dispose();
}
#Override
public void actionPerformed(ActionEvent e) {
rotation=Math.atan2(player.centerX()-planet.centerX(), player.centerY()-planet.centerY());
player.x+=dx;
player.y+=dy;
repaint();
}
#Override
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_LEFT) {
dx = -5;
}
if (key == KeyEvent.VK_RIGHT) {
dx = 5;
}
if (key == KeyEvent.VK_UP) {
dy = -5;
}
if (key == KeyEvent.VK_DOWN) {
dy = 5;
}
}
#Override
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_LEFT) {
if (dx==-5)
dx = 0;
}
if (key == KeyEvent.VK_RIGHT) {
if (dx==5)
dx = 0;
}
if (key == KeyEvent.VK_UP) {
if (dy==-5)
dy = 0;
}
if (key == KeyEvent.VK_DOWN) {
if (dy==5)
dy = 0;
}
}
#Override
public void addNotify(){
super.addNotify();
timer=new Timer(10,this);
timer.start();
addKeyListener(this);
}
#Override
public void keyTyped(KeyEvent arg0) {
}
}
public class Planet{
public int x;
public int y;
private int radius;
public Planet(int x,int y,int radius){
this.x=x;
this.y=y;
this.radius=radius;
}
public int getX(){
return x;
}
public int getY(){
return y;
}
public int getRadius(){
return radius;
}
public int centerX(){
return x+(radius/2);
}
public int centerY(){
return y+(radius/2);
}
}
public class Player {
public int x;
public int y;
private int width;
private int height;
public Player(int x,int y,int width,int height){
this.x=x;
this.y=y;
this.width=width;
this.height=height;
}
public int getX(){
return x;
}
public int getY(){
return y;
}
public int getHeight(){
return height;
}
public int getWidth(){
return width;
}
public int centerX(){
return x+(width/2);
}
public int centerY(){
return y+(height/2);
}
}
This is working for me. I changed the sign of the angle, and the way that the player is drawn.
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
g2d=(Graphics2D)g;
// Draw planet
g2d.fillOval(planet.getX(), planet.getY(), planet.getRadius(), planet.getRadius());
// Draw player
g2d.setColor(Color.BLUE);
g2d.rotate(rotation, player.centerX(), player.centerY());
Rectangle rect = new Rectangle(player.centerX()-(player.getWidth()/2), player.centerY()-(player.getHeight()/2), player.getWidth(),player.getHeight());
g2d.draw(rect);
g2d.dispose();
}
#Override
public void actionPerformed(ActionEvent e) {
rotation=Math.atan2(+player.centerX()-planet.centerX(), - player.centerY()+planet.centerY());
player.x+=dx;
player.y+=dy;
repaint();
}
I haven't checked the calculation of the rotation, but I think fillOval should use twice the radius to draw the planet:
g2d.fillOval(planet.getX(), planet.getY(), planet.getRadius()*2, planet.getRadius()*2);