I'm writing a program to transform, rotate and scale a 2d square. I have the transformation and rotation working but I need help with the scaling. I can't seem to find any help on the internet to help since I have to use a math equation and I can't find the equation needed. Just so you know I don't want to use gl.glScaled(). I need to use a math equation but I can't figure it out.
package lab2;
public class Square {
public double [][] vertices = new double[4][2];
public Square(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4)
{
vertices[0][0]=x1;
vertices[0][1]=y1;
vertices[1][0]=x2;
vertices[1][1]=y2;
vertices[2][0]=x3;
vertices[2][1]=y3;
vertices[3][0]=x4;
vertices[3][1]=y4;
}
public double area()
{
return (vertices[1][0]-vertices[0][0])*(vertices[1][0]-vertices[0][0])+(vertices[1][1]-vertices[0][1])*(vertices[1][1]-vertices[0][1]);
}
public void translate(double tx, double ty)
{
for(int i=0;i<vertices.length;i++)
{
vertices[i][0]+=tx;
vertices[i][1]+=ty;
}
}
public void rotate(double theta)
{
//double x =0;
double x = (vertices[0][0]+vertices[2][0])/2;
double y = (vertices[0][1]+vertices[2][1])/2;
double oldX;
int i;
for(i = 0; i < 4; i++){
oldX = vertices[i][0];
vertices[i][0] = x + (vertices[i][0]-x)*Math.cos(theta*0.0174532925199)-(vertices[i][1]- y)*Math.sin(theta*0.0174532925199);
vertices[i][1] = y + (oldX-x)*Math.sin(theta*0.0174532925199)+(vertices[i][1]-y)*Math.cos(theta*0.0174532925199);
}
}
public void scale(double sx, double sy)
{
}
}
Then I also have this SquareControl.java so that I can control how I want it to work so for this program I'll be using key events
package lab2;
import java.awt.Frame;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.media.opengl.*;
import javax.media.opengl.awt.GLCanvas;
import com.sun.opengl.util.Animator;
import com.sun.opengl.util.FPSAnimator;
public class Square_Control implements GLEventListener, KeyListener {
Square square = new Square(100,100,200,100,200,200,100,200);
boolean rotating = false;
boolean scaling = false;
boolean enlarge = true;
double theta = 1;
double sx = 1.01, sy = 1.01;
GLProfile glp;
GLCapabilities caps;
GLCanvas canvas;
public Square_Control()
{
glp = GLProfile.getDefault();
caps = new GLCapabilities(glp);
canvas = new GLCanvas(caps);
Frame frame = new Frame("AWT Window Test");
frame.setSize(300, 300);
frame.add(canvas);
frame.setVisible(true);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
canvas.addGLEventListener(this);
canvas.addKeyListener(this);
canvas.requestFocus();
Animator animator = new FPSAnimator(canvas,60);
animator.add(canvas);
animator.start();
}
public static void main(String[] args) {
Square_Control sqc = new Square_Control();
}
public void update()
{
if (rotating)
square.rotate(theta);
if (scaling)
{
square.scale(1, 1);
}
}
#Override
public void display(GLAutoDrawable drawable) {
update();
GL2 gl = drawable.getGL().getGL2();
gl.glClear(GL.GL_COLOR_BUFFER_BIT);
gl.glColor3f(1, 0, 0);
gl.glBegin(GL.GL_LINE_LOOP);
gl.glVertex2d(square.vertices[0][0], square.vertices[0][1]);
gl.glVertex2d(square.vertices[1][0], square.vertices[1][1]);
gl.glVertex2d(square.vertices[2][0], square.vertices[2][1]);
gl.glVertex2d(square.vertices[3][0], square.vertices[3][1]);
gl.glEnd();
}
#Override
public void dispose(GLAutoDrawable drawable) {
// TODO Auto-generated method stub
}
#Override
public void init(GLAutoDrawable drawable) {
// TODO Auto-generated method stub
GL2 gl = drawable.getGL().getGL2();
gl.glMatrixMode(gl.GL_PROJECTION);
gl.glLoadIdentity();
gl.glOrtho(0, 300, 0, 300, -1, 1);
gl.glViewport(0, 0, 300, 300);
}
#Override
public void reshape(GLAutoDrawable drawable, int x, int y, int width,
int height) {
// TODO Auto-generated method stub
}
#Override
public void keyPressed(KeyEvent arg0) {
if (arg0.getKeyCode() == KeyEvent.VK_RIGHT)
square.translate(4, 0);
else if (arg0.getKeyCode() == KeyEvent.VK_LEFT)
square.translate(-4, 0);
else if (arg0.getKeyCode() == KeyEvent.VK_UP)
square.translate(0, 4);
else if (arg0.getKeyCode() == KeyEvent.VK_DOWN)
square.translate(0, -4);
//also add code to toggle rotation/scaling
if(arg0.getKeyCode() == KeyEvent.VK_R)
{
rotating = !rotating;
}
if(arg0.getKeyCode() == KeyEvent.VK_S)
{
scaling = !scaling;
}
}
#Override
public void keyReleased(KeyEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void keyTyped(KeyEvent arg0) {
// TODO Auto-generated method stub
}
}
To scale an object, you simply have to multiply each vertex by your scaling factor. A scaling factor of 1.0 will do nothing while a scaling factor of 2.0 will double de position of each vertex, hence scaling it AND probably translating it.
If you want the object to stay in place, you'll have to first translate it to your object's center, scale, then translate back to it's original position.
That is if you want to do the job software.
You should consider using Matrix functions. glRotatef, glTranslatef and glScalef.
Related
I have an assignment to create a 2D game, this game must use an abstract class Shape which is used to draw shapes. I decided to make a 2D platformer, but it's my first time doing something like this. I am trying to implement collision detection, and decided to create an offset of my player object to see if it collides with my rectangle object, and stop movement if it does. This is only working for the top side, however on the right, left and botton the player will move through the rectangle and I don't understand why. I expected the collision detection to work for all sides. I would like to know how I can change my collision detection to work for all sides of the rectangle.
Here's a gif showing what happens:
My App class:
package A2;
import javax.swing.*;
import java.awt.*;
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.TreeSet;
import static java.awt.event.KeyEvent.*;
public class App extends JFrame {
private static final int GRAVITY = 10;
private static final int MAX_FALL_SPEED = 30;
public App() {
final Player player = new Player(200, 300);
final Rectangle rectangle = new Rectangle(100, 400);
JPanel mainPanel = new JPanel() {
public void paintComponent(Graphics g) {
super.paintComponent(g);
player.draw(g);
rectangle.draw(g);
}
};
mainPanel.addKeyListener(new controlHandler(this, player, rectangle));
mainPanel.setFocusable(true);
add(mainPanel);
setLayout(new GridLayout());
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setSize(600, 600);
}
class controlHandler implements ActionListener, KeyListener {
int keyCode;
App app;
Player player;
Rectangle rectangle;
TreeSet<Integer> keys = new TreeSet<>();
Timer time = new Timer(5, this);
boolean collision = false;
public controlHandler(App app, Player player, Rectangle rectangle) {
this.app = app;
this.player = player;
this.rectangle = rectangle;
time.start();
}
public void actionPerformed(ActionEvent e) {
player.x += player.xVelocity;
player.y += player.yVelocity;
Rectangle2D offset = player.getOffsetBounds();
if(offset.intersects(this.rectangle.wallObj.getBounds2D())){
collision = true;
player.xVelocity = 0;
player.yVelocity = 0;
}
else collision = false;
repaint();
}
public void keyPressed(KeyEvent e) {
keyCode = e.getKeyCode();
keys.add(keyCode);
switch (keyCode) {
case VK_UP:
moveUp();
break;
case VK_DOWN:
moveDown();
break;
case VK_LEFT:
moveLeft();
break;
case VK_RIGHT:
moveRight();
break;
}
}
public void keyReleased(KeyEvent e) {
released();
}
public void keyTyped(KeyEvent e) { }
public void moveUp() {
player.xVelocity = 0;
player.yVelocity = -2;
}
public void moveDown() {
if(!collision) {
player.xVelocity = 0;
player.yVelocity = 2;
}
}
public void moveLeft() {
player.xVelocity = -2;
player.yVelocity = 0;
}
public void moveRight() {
player.xVelocity = 2;
player.yVelocity = 0;
}
public void released() {
player.xVelocity = 0;
player.yVelocity = 0;
}
}
public static void main(String[] args) {
App app = new App();
app.setVisible(true);
}
}
abstract class Shape {
public double x;
public double y;
public void draw(Graphics g) { }
}
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 length = 60;
public double top;
public double right;
public double left;
public double bottom;
public Rectangle2D playerObj;
public Player(double x, double y) {
this.x = x;
this.y = y;
playerObj = new Rectangle2D.Double(x, y, length, length);
}
public Rectangle2D getOffsetBounds(){
return new Rectangle2D.Double(x + xVelocity , y + yVelocity , length, length);
}
public void draw(Graphics g) {
playerObj = new Rectangle2D.Double(x, y, length, length);
g.setColor(Color.BLACK);
Graphics2D g2 = (Graphics2D)g;
g2.fill(playerObj);
}
}
Rectangle class (will be a platform):
package A2;
import java.awt.*;
import java.awt.geom.Rectangle2D;
public class Rectangle extends Shape {
public double width = 400;
public double height = 30;
public double top;
public double right;
public double left;
public double bottom;
public Rectangle2D wallObj;
public Rectangle(double x, double y) {
this.x = x;
this.y = y;
wallObj = new Rectangle2D.Double(x, y, width, height);
}
public void draw(Graphics g) {
g.setColor(Color.ORANGE);
Graphics2D g2 = (Graphics2D)g;
g2.fill(wallObj);
}
}
So, based on my understanding, your collision detection process is basically to create a "virtual" instance of the object and determine if it will collide.
Your code is actually work, you can tell by the fact that the object "stops" moving once it collides, but what you're not doing, is reseting the objects position after it.
Let's look at the original code...
public void actionPerformed(ActionEvent e) {
player.x += player.xVelocity;
player.y += player.yVelocity;
Rectangle2D offset = player.getOffsetBounds();
if (offset.intersects(this.rectangle.wallObj.getBounds2D())) {
collision = true;
player.xVelocity = 0;
player.yVelocity = 0;
} else {
collision = false;
}
repaint();
}
Update the position of the object
Create a virtual instance of the object, which applies the velocity to the objects current position ... again?
Determine if the object collides
Stop the movement if any
... where do you reset the position of object so it's no longer colliding?!?
Instead, you shouldn't set the position of the object until AFTER you've determine if a collision has occurred or not, for example...
public void actionPerformed(ActionEvent e) {
Rectangle2D offset = player.getOffsetBounds();
if (offset.intersects(this.rectangle.wallObj.getBounds2D())) {
collision = true;
player.xVelocity = 0;
player.yVelocity = 0;
} else {
player.x += player.xVelocity;
player.y += player.yVelocity;
collision = false;
}
repaint();
}
The problem with this approach, though, is if the velocity is large enough, the object will appear not to collide, but stop a little before it, as the amount of change is larger than the remaining gap.
What you need to do, is once you've detected a collision is calculate the difference between the amount you want to move and the space available and move the object only by that amount instead
I am attempting to create a Big Bang world which contains a circle whose initial state should have it moving one pixel diagonally to the bottom-right. Every time the user presses the four arrow keys, the circle should move one pixel towards that direction and keep moving. For example, if I keep pressing the right arrow key, the circle should move towards the right and keep moving faster and faster each time I press it. The problem I am having is that I can't get the circle to move at all! I thought changing x and y coordinates oft he circle for each method should move it accordingly. What am I doing wrong? What can I do to have the circle move as I have described it? Here is the file Game.java that I need to fix:
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class Game implements World {
public Game() { }
int x, y = 200;
int width, height = 100;
void Circle(int x, int y, int width, int height){
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public void draw(Graphics g) {
int x = 200;
int y = 200;
int width = 100;
int height = 100;
g.setColor(Color.red);
g.fillOval(x,
y,
width,
height);
}
public void teh() {
this.x++;
this.y++;
}
public void meh(MouseEvent e) {
int x = e.getX(), y = e.getY();
System.out.println("Mouse event detected.");
}
public void keh(KeyEvent e) {
int x = e.getKeyLocation(), y = e.getKeyLocation();
int key = e.getKeyCode();
if (key == KeyEvent.VK_UP){
this.y--;
System.out.println("Up.");
}
else if (key == KeyEvent.VK_DOWN){
this.y++;
System.out.println("Down.");
}
else if (key == KeyEvent.VK_RIGHT){
this.x++;
System.out.println("Right.");
}
else if (key == KeyEvent.VK_LEFT){
this.x--;
System.out.println("Left.");
}
else{}
// switch( keyCode ) {
// case KeyEvent.VK_UP:
// // handle up
// break;
// case KeyEvent.VK_DOWN:
// // handle down
// break;
// case KeyEvent.VK_LEFT:
// // handle left
// break;
// case KeyEvent.VK_RIGHT :
// // handle right
// break;
// }
}
public boolean hasEnded() {
return false;
}
public void sayBye() {
System.out.println("BYE!");
}
public static void main(String[] args) {
BigBang b = new BigBang(new Game());
b.start( 50, // delay
400 // size
);
}
}
These are the supplementary files that are used but should remain untouched. I am including them for your reference:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class BigBang extends JComponent implements ActionListener, MouseListener, MouseMotionListener, KeyListener {
Timer timer;
World world;
public BigBang(World world) {
this.world = world;
this.addMouseListener(this);
this.addMouseMotionListener(this);
this.addKeyListener(this);
this.setFocusable(true);
this.requestFocus();
}
public void start(int delay, int size) {
JFrame a = new JFrame();
a.add( this );
a.setVisible(true);
a.setSize(size, size);
this.timer = new Timer(delay, this);
this.timer.start();
}
public void mouseEntered(MouseEvent e) { }
public void mouseExited(MouseEvent e) { }
public void mousePressed(MouseEvent e) {
this.world.meh(e);
this.repaint();
}
public void mouseDragged(MouseEvent e) {
this.world.meh(e);
this.repaint();
}
public void mouseMoved(MouseEvent e) { }
public void mouseReleased(MouseEvent u) {
this.world.meh(u);
this.repaint();
}
public void mouseClicked(MouseEvent e) { }
public void keyPressed(KeyEvent e) {
this.world.keh(e);
this.repaint();
}
public void keyReleased(KeyEvent e) { }
public void keyTyped(KeyEvent e) { }
// int count;
public void actionPerformed(ActionEvent e) {
// this.count += 1;
// System.out.println("Ouch" + this.count);
if (this.world.hasEnded()) {
this.timer.stop();
this.world.sayBye();
} else {
this.world.teh();
}
this.repaint();
}
public void paintComponent(Graphics g) {
this.world.draw(g);
}
}
And the interface World.java:
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
interface World {
void draw(Graphics g);
void teh();
void meh(MouseEvent e);
void keh(KeyEvent e);
boolean hasEnded();
void sayBye();
}
Where does my mistake lie? Why am I not able to move the circle when the arrow keys are pressed? How can I continue to add on to the velocity of the object each time the arrow key is pressed? Any modifications or advice will be helpful.
The issue is in your draw method:
public void draw(Graphics g)
{
int x = 200;
int y = 200;
int width = 100;
int height = 100;
g.setColor(Color.red);
g.fillOval(x, y, width, height);
}
You are constantly making new local variables, x, y, width, and height, and drawing with those
Instead you should be using the variables your class already has designed:
public void draw(Graphics g)
{
g.setColor(Color.red);
g.fillOval(x, y, width, height);
}
I am making a game and tutorials for how to make it on youtube. Here is the link to the channel. I explain the first part of what I have and why I have it because I know that is helpful for filling you in.
Link to part 1(Then watch the rest of parts. #Chris, this is helpful for solving the problem so don't flag the post).
https://www.youtube.com/watch?v=IRn_ZGhJZ94
I noticed as I was testing out my code for part 4. before recording, the game lagged HORRIBLY. I have alot of code, and any help is appreciated.
Game class:
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.Timer;
#SuppressWarnings("serial")
public class Game extends JPanel implements ActionListener{
Timer mainTimer;
Paddle paddle;
Ball ball;
int blockCount = 16;
static ArrayList<Block> blocks = new ArrayList<Block>();
public Game() {
setFocusable(true);
paddle = new Paddle(250, 300);
addKeyListener(new KeyAdapt(paddle));
ball = new Ball(275, 280);
mainTimer = new Timer(10, this);
mainTimer.start();
}
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
ImageIcon ic = new ImageIcon("C:/Users/Elliot/Desktop/Eclipse Game/background.png");
g2d.drawImage(ic.getImage(), 0, 0, null);
paddle.draw(g2d);
ball.draw(g2d);
for(int i = 0; i < blockCount; i++) {
Block b = blocks.get(i);
b.draw(g2d);
}
}
#Override
public void actionPerformed(ActionEvent arg0) {
paddle.update();
ball.update();
for(int i = 0; i < blocks.size(); i++) {
Block b = blocks.get(i);
b.update();
}
repaint();
startGame();
}
public void addBlock(Block b) {
blocks.add(b);
}
public static void removeBlock(Block b) {
blocks.remove(b);
}
public static ArrayList<Block> getBlockList() {
return blocks;
}
public void startGame() {
for(int i = 0; i < blockCount; i++) {
addBlock(new Block(i*60 + 7, 20));
addBlock(new Block(i*60 + 7, 0));
}
}
}
Main class(The frame part):
import javax.swing.JFrame;
public class Main {
public static void main(String[] args) {
JFrame frame = new JFrame("Game");
frame.setSize(500, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new Game());
frame.setResizable(false);
frame.setVisible(true);
}
}
Key Adapt class:
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
public class KeyAdapt extends KeyAdapter{
Paddle p;
public KeyAdapt(Paddle paddle) {
p = paddle;
}
public void keyPressed(KeyEvent e) {
p.keyPressed(e);
}
public void keyReleased(KeyEvent e) {
p.keyReleased(e);
}
}
Paddle class:
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;
import javax.swing.ImageIcon;
public class Paddle {
int velX;
int speed = 3;
static int x1, y1;
public Paddle(int x1, int y1) {
this.x1 = x1;
this.y1 = y1;
}
public void update() {
x1+=velX;
checkCollisions();
}
public void draw(Graphics2D g2d) {
g2d.drawImage(getPaddleImg(), x1, y1, null);
}
public static Image getPaddleImg() {
ImageIcon ic = new ImageIcon("C:/Users/Elliot/Desktop/Eclipse Game/paddle.png");
return ic.getImage();
}
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if(key==KeyEvent.VK_D) {
velX = speed;
} else if(key==KeyEvent.VK_A){
velX = -speed;
}
}
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if(key==KeyEvent.VK_D) {
velX = 0;
} else if(key==KeyEvent.VK_A){
velX = 0;
}
}
public void checkCollisions() {
if(getBounds().getX() + getBounds().getWidth() >= 500) {
x1 = 440;
} else if(getBounds().getX() <= 0) {
x1 = 0;
}
}
public static Rectangle getBounds() {
return new Rectangle(x1, y1 - 1, getPaddleImg().getWidth(null), getPaddleImg().getHeight(null));
}
}
Ball class:
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;
public class Ball {
int velX;
int velY;
int speed = 3;
int x, y;
public Ball(int x, int y) {
this.x = x;
this.y = y;
}
public void update() {
x+=velX;
y+=velY;
checkCollisions();
}
public void draw(Graphics2D g2d) {
g2d.drawImage(getBallImg(), x, y, null);
}
public Image getBallImg() {
ImageIcon ic = new ImageIcon("C:/Users/Elliot/Desktop/Eclipse Game/ball.png");
return ic.getImage();
}
public void checkCollisions() {
for(int i = 0; i < Game.getBlockList().size(); i++) {
Block b = Game.getBlockList().get(i);
if(getBounds().intersects(b.getBounds()) && velX!=-speed) {
velY=speed;
velX =- speed;
Game.removeBlock(b);
}
else if(getBounds().intersects(b.getBounds())) {
velY=speed;
velX = speed;
Game.removeBlock(b);
}
}
if(getBounds().intersects(Paddle.getBounds())) {
velY = -speed;
} else if (getBounds().getY() <= 0 && velX!=speed) {
velY = speed;
velX =- speed;
}else if (getBounds().getY() <= 0 && velX!=-speed) {
velY = speed;
velX = speed;
} else if(getBounds().getY() >= 400) {
JOptionPane.showMessageDialog(null, "You Lost! :( ");
System.exit(0);
}
if(getBounds().getX() <= 0) {
velX = speed;
} else if(getBounds().getX() >= 500 - getBounds().getWidth()) {
velX = -speed;
}
}
public Rectangle getBounds() {
return new Rectangle(x, y, getBallImg().getWidth(null), getBallImg().getHeight(null));
}
}
Block class:
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import javax.swing.ImageIcon;
public class Block {
int x2, y2;
public Block(int x2, int y2) {
this.x2 = x2;
this.y2 = y2;
}
public void update() {
}
public void draw(Graphics2D g2d){
g2d.drawImage(getBlockImg(), x2, y2, null);
}
public static Image getBlockImg() {
ImageIcon ic = new ImageIcon("C:/Users/Elliot/Desktop/Eclipse Game/block.png");
return ic.getImage();
}
public Rectangle getBounds() {
return new Rectangle(x2, y2, getBlockImg().getWidth(null), getBlockImg().getHeight(null));
}
}
I also have a folder called Eclipse Game on my desktop and I refer to it in my code.
Again, I understand this is alot but any idea with making it lag less is helpful. Also, watching the tutorial (look at the beginning for the link) on making what I have finished so far will help make it less confusing for you to understand how the code works. The game seriously lags so much I cannot play.
There are multiple issues.
The first, as I already mentioned in my comment, is that you're calling startGame() inside your timer action listener:
#Override
public void actionPerformed(ActionEvent arg0) {
paddle.update();
ball.update();
for(int i = 0; i < blocks.size(); i++) {
Block b = blocks.get(i);
b.update();
}
repaint();
startGame();
}
This is adding 3,200 blocks every second to the game, so you don't want that. I think the simplest place to put startGame() is at the end of the game constructor:
public Game() {
setFocusable(true);
paddle = new Paddle(250, 300);
addKeyListener(new KeyAdapt(paddle));
ball = new Ball(275, 280);
mainTimer = new Timer(10, this);
mainTimer.start();
startGame();
}
The other really big problem is that you're constantly reloading the images all the time. For example, look at this snippet:
if(getBounds().intersects(b.getBounds()) && velX!=-speed) {
velY=speed;
velX =- speed;
Game.removeBlock(b);
}
else if(getBounds().intersects(b.getBounds())) {
velY=speed;
velX = speed;
Game.removeBlock(b);
}
That is 4 calls to getBounds(), and if we take a look at that:
return new Rectangle(x2, y2, getBlockImg().getWidth(null), getBlockImg().getHeight(null));
You are loading 2 images which in total is 4*2*blockCount images every 10ms, just for this one method. Instead of loading images all the time, do something like this:
class GameResources {
static Image ballImage;
static Image paddleImage;
static Image blockImage;
// call GameResources.loadResources() at the
// beginning of main() or something
static void loadResources() {
// load all 3 images once here and be done
ballImage = ...;
paddleImage = ...;
blockImage = ...;
}
Then finally, you have an issue with removing items from the list while iterating over it, Ball.checkCollisions:
for(int i = 0; i < Game.getBlockList().size(); i++) {
Block b = Game.getBlockList().get(i);
if(getBounds().intersects(b.getBounds()) && velX!=-speed) {
velY=speed;
velX =- speed;
// removeBlock changes blocks.size()
Game.removeBlock(b);
}
else if(getBounds().intersects(b.getBounds())) {
velY=speed;
velX = speed;
// removeBlock changes blocks.size()
Game.removeBlock(b);
}
}
Instead you need to do something like this:
Iterator<Block> iter = Game.getBlockList().iterator();
while (it.hasNext()) {
Block b = it.next();
if(getBounds().intersects(b.getBounds()) && velX!=-speed) {
velY=speed;
velX =- speed;
// safely removing
it.remove();
}
else if(getBounds().intersects(b.getBounds())) {
velY=speed;
velX = speed;
// safely removing
it.remove();
}
}
And another possible boundary issue in Game.paint:
// using blockCount after possibly
// removing items from the list
// vvvvvvvvvv
for(int i = 0; i < blockCount; i++) {
Block b = blocks.get(i);
b.draw(g2d);
}
For simple iterations like this, you should use for-each:
for(Block b : blocks) {
b.draw(g2d);
}
After all of that the game runs pretty smoothly, except for some type of issue with the key listener which I didn't have time to figure out. I might look at it again after dinner.
edit:
I noticed a lot of other small things, so here is the program fixed up a bit more with my comments.
Some of the classes aren't public anymore just because I had them all in one source file.
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JOptionPane;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyAdapter;
import java.util.ArrayList;
import java.util.Iterator;
import java.awt.Rectangle;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Dimension;
import java.net.URL;
import javax.imageio.ImageIO;
import java.io.IOException;
import java.io.File;
public class BlockGame {
public static void main(String[] args) {
// Swing program should always begin on the Swing
// thread with a call to invokeLater.
// See https://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
try {
// change this to
// .loadImages();
GameResources.loadInternetImages();
} catch (IOException x) {
x.printStackTrace();
return;
}
JFrame frame = new JFrame("Game");
// frame.setSize(500, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// frame.add(new Game());
// Instead of calling setSize on the JFrame
// directly, set a preferred size on the game
// panel, then call pack() on the JFrame
Game game = new Game();
game.setPreferredSize(new Dimension(500, 400));
frame.add(game);
frame.pack();
frame.setResizable(false);
frame.setVisible(true);
// I started the game here instead
// of in the game loop, so the panel
// is visible and stuff beforehand.
game.startGame();
}
});
}
}
class Game extends JPanel implements ActionListener {
Timer mainTimer;
Paddle paddle;
Ball ball;
// I removed this because it's only ever
// used by startGame.
// int blockCount = 16;
// I changed this to an instance variable
// (not static) and passed the game in to
// update so the game objects can access
// it.
ArrayList<Block> blocks = new ArrayList<Block>();
public Game() {
setFocusable(true);
paddle = new Paddle(250, 300);
addKeyListener(new KeyAdapt(paddle));
ball = new Ball(275, 280);
mainTimer = new Timer(10, this);
// I moved this to the startGame() method
// mainTimer.start();
}
// Swing programs should override paintComponent
// instead of paint.
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
// You should create a copy instead of
// directly using the graphics object which
// the component uses.
// This is so any changes you make to it
// don't affect the Swing paint routines.
Graphics2D g2d = (Graphics2D) g.create();
// ImageIcon ic = new ImageIcon("C:/Users/Elliot/Desktop/Eclipse Game/background.png");
// g2d.drawImage(ic.getImage(), 0, 0, null);
// Painting static resource.
g2d.drawImage(GameResources.backgroundImage, 0, 0, null);
paddle.draw(g2d);
ball.draw(g2d);
// This loop will throw an out of bounds
// exception once the first block is removed.
// vvvvvvvvvv
// for(int i = 0; i < blockCount; i++) {
// Block b = blocks.get(i);
// b.draw(g2d);
// }
// using for each
for (Block b : blocks) {
b.draw(g2d);
}
// Dispose the copied graphics when you're done.
g2d.dispose();
}
#Override
public void actionPerformed(ActionEvent arg0) {
paddle.update(this);
ball.update(this);
// for(int i = 0; i < blocks.size(); i++) {
// Block b = blocks.get(i);
// b.update();
// }
for (Block b : blocks) {
b.update(this);
}
repaint();
// I moved this to main
// startGame();
}
public void addBlock(Block b) {
blocks.add(b);
}
public void removeBlock(Block b) {
blocks.remove(b);
}
public ArrayList<Block> getBlockList() {
return blocks;
}
// I added this method so that the
// ball can access the paddle without
// static variables.
public Paddle getPaddle() {
return paddle;
}
public void startGame() {
// So the method won't be called twice
// and put the game in some unexpected
// state.
if (mainTimer.isRunning()) {
throw new IllegalStateException("game already started");
}
int initialBlockCount = 16;
for(int i = 0; i < initialBlockCount; i++) {
addBlock(new Block(i*60 + 7, 20));
addBlock(new Block(i*60 + 7, 0));
}
mainTimer.start();
}
}
// Generally speaking you should use
// Swing key bindings now, instead of
// key listeners.
//
// Key listeners have problems with
// the focus system: Swing components
// only send out key events when they
// have the focus.
//
// Key bindings don't have this issue.
//
// You can set up key bindings so they
// trigger any time the key is pressed
// in the focused window.
//
// https://docs.oracle.com/javase/tutorial/uiswing/misc/keybinding.html
//
class KeyAdapt extends KeyAdapter {
Paddle p;
public KeyAdapt(Paddle paddle) {
p = paddle;
}
public void keyPressed(KeyEvent e) {
p.keyPressed(e);
}
public void keyReleased(KeyEvent e) {
p.keyReleased(e);
}
}
class Paddle {
int velX;
int speed = 3;
// I changed these from static
// to instance variables.
int x1, y1;
// I added these variables to
// help with the key listener
// logic.
boolean leftPressed, rightPressed;
public Paddle(int x1, int y1) {
this.x1 = x1;
this.y1 = y1;
}
public void update(Game game) {
x1 += velX;
checkCollisions();
}
public void draw(Graphics2D g2d) {
g2d.drawImage(GameResources.paddleImage, x1, y1, null);
}
// public static Image getPaddleImg() {
// ImageIcon ic = new ImageIcon("C:/Users/Elliot/Desktop/Eclipse Game/paddle.png");
// return ic.getImage();
// }
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
// This logic is a little more robust
// because it handles cases where both
// keys are being held at the same time.
// Also see computeVelX().
if (key == KeyEvent.VK_D) {
leftPressed = true;
// velX = speed;
} else if (key == KeyEvent.VK_A) {
rightPressed = true;
// velX = -speed;
}
computeVelX();
}
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
// This logic is a little more robust
// because it handles cases where both
// keys are being held at the same time.
// Also see computeVelX().
if (key == KeyEvent.VK_D) {
leftPressed = false;
// velX = 0;
} else if (key == KeyEvent.VK_A) {
rightPressed = false;
// velX = 0;
}
computeVelX();
}
public void computeVelX() {
// This way the keys will never
// "stick". If both keys are
// held at the same time, velX
// is just 0 until one of the
// keys is released.
velX = 0;
if (leftPressed) {
velX += speed;
}
if (rightPressed) {
velX -= speed;
}
}
public void checkCollisions() {
// I used a variable instead of calling
// getBounds() repeatedly.
Rectangle bounds = getBounds();
if (bounds.getX() + bounds.getWidth() >= 500) {
x1 = 440;
} else if (bounds.getX() <= 0) {
x1 = 0;
}
}
// I change this from static to an instance method.
public Rectangle getBounds() {
// return new Rectangle(x1, y1 - 1, getPaddleImg().getWidth(null), getPaddleImg().getHeight(null));
int width = GameResources.paddleImage.getWidth(null);
int height = GameResources.paddleImage.getHeight(null);
return new Rectangle(x1, y1 - 1, width, height);
}
}
class Ball {
int velX;
int velY;
int speed = 3;
int x, y;
public Ball(int x, int y) {
this.x = x;
this.y = y;
}
public void update(Game game) {
x += velX;
y += velY;
checkCollisions(game);
}
public void draw(Graphics2D g2d) {
// g2d.drawImage(getBallImg(), x, y, null);
g2d.drawImage(GameResources.ballImage, x, y, null);
}
// public Image getBallImg() {
// ImageIcon ic = new ImageIcon("C:/Users/Elliot/Desktop/Eclipse Game/ball.png");
// return ic.getImage();
// }
public void checkCollisions(Game game) {
// Using an iterator instead of looping with size()
// directly, because we want to remove items from
// the list while iterating.
// The problem with removing while iterating with
// size() is that once you remove an element, the
// list shifts all the other elements back by 1,
// so on the next iteration of the loop you end
// up skipping an item.
// (Say you remove the element at index 5. Then
// all the elements shift back, so that e.g. the
// element at index 6 is now at index 5. The variable
// i is incremented, so you end up skipping the element
// that was at index 6 before the removal.
Iterator<Block> iter = game.getBlockList().iterator();
Rectangle bounds = getBounds();
while (iter.hasNext()) {
Block b = iter.next();
Rectangle bBounds = b.getBounds();
if (bounds.intersects(bBounds) && velX != -speed) {
velY = speed;
velX =- speed;
// Game.removeBlock(b);
iter.remove();
} else if (bounds.intersects(bBounds)) {
velY = speed;
velX = speed;
// Game.removeBlock(b);
iter.remove();
}
}
//
Rectangle pBounds = game.getPaddle().getBounds();
if (bounds.intersects(pBounds)) {
velY = -speed;
} else if (bounds.getY() <= 0 && velX != speed) {
velY = speed;
velX =- speed;
} else if (bounds.getY() <= 0 && velX != -speed) {
velY = speed;
velX = speed;
} else if (bounds.getY() >= 400) {
JOptionPane.showMessageDialog(null, "You Lost! :( ");
System.exit(0);
}
if (bounds.getX() <= 0) {
velX = speed;
} else if(bounds.getX() >= 500 - bounds.getWidth()) {
velX = -speed;
}
}
public Rectangle getBounds() {
// return new Rectangle(x, y, getBallImg().getWidth(null), getBallImg().getHeight(null));
int width = GameResources.ballImage.getWidth(null);
int height = GameResources.ballImage.getHeight(null);
return new Rectangle(x, y, width, height);
}
}
class Block {
int x2, y2;
public Block(int x2, int y2) {
this.x2 = x2;
this.y2 = y2;
}
public void update(Game game) {
}
public void draw(Graphics2D g2d){
// g2d.drawImage(getBlockImg(), x2, y2, null);
g2d.drawImage(GameResources.blockImage, x2, y2, null);
}
// public static Image getBlockImg() {
// ImageIcon ic = new ImageIcon("C:/Users/Elliot/Desktop/Eclipse Game/block.png");
// return ic.getImage();
// }
public Rectangle getBounds() {
// return new Rectangle(x2, y2, getBlockImg().getWidth(null), getBlockImg().getHeight(null));
int width = GameResources.blockImage.getWidth(null);
int height = GameResources.blockImage.getHeight(null);
return new Rectangle(x2, y2, width, height);
}
}
class GameResources {
public static Image backgroundImage;
public static Image blockImage;
public static Image ballImage;
public static Image paddleImage;
public static void loadImages() throws IOException {
// Load images once here.
// I didn't test this method since I don't have the images, but it
// should work. ImageIO.read will give better error messages than
// using ImageIcon. ImageIcon.getImage() will just return null if
// there was a problem, which doesn't tell you what the problem
// actually was.
paddleImage =
ImageIO.read(new File("C:/Users/Elliot/Desktop/Eclipse Game/paddle.png"));
ballImage =
ImageIO.read(new File("C:/Users/Elliot/Desktop/Eclipse Game/ball.png"));
blockImage =
ImageIO.read(new File("C:/Users/Elliot/Desktop/Eclipse Game/block.png"));
backgroundImage =
ImageIO.read(new File("C:/Users/Elliot/Desktop/Eclipse Game/background.png"));
}
public static void loadInternetImages() throws IOException {
// These images are from
// http://stackoverflow.com/questions/19209650/example-images-for-code-and-mark-up-qas
paddleImage =
ImageIO.read(new URL("http://i.stack.imgur.com/gYxHm.png"));
ballImage =
ImageIO.read(new URL("http://i.stack.imgur.com/gJmeJ.png"));
blockImage =
ImageIO.read(new URL("http://i.stack.imgur.com/F0JHK.png"));
backgroundImage =
ImageIO.read(new URL("http://i.stack.imgur.com/P59NF.png"));
}
}
I'm drawing a knob as a component and I'm using swing. The result seems ok but when I click on the knob and move my mouse (up or down) to change the knob position, the knob repainted is ugly, as if there were 2 layers superposed. More over, I have this result only for the "small sizes" of my knob. If I enlarge my frame, this ugly effect disappear. Does someone could explain me what happens and how to improve my knob ?
Thanks a lot for those who will help me.
Here is my code :
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.MouseInfo;
import java.awt.Point;
import java.awt.PointerInfo;
import java.awt.RenderingHints;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.geom.Line2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Knob extends JPanel implements MouseListener {
int length, originX, originY, centerX, centerY, width, height, diameter, squareLength;
int minorTick, majorTick, xTick, yTick, xCursor, yCursor;
int xMouse, yMouse, xMouseOrigin, yMouseOrigin;
float yDeltaMouse;
double angleOrigin, angleRange, angle;
double cursorValue;
double initialCursorValue;
Color backgroundColor, knobColor;
boolean mousePressed;
Thread t;
private double knobValue;
private String title = new String("");
private int titleWidth;
Knob (double initialValue, Color c, int majorTick, int minorTick) {
//System.out.println("Knob");
cursorValue=initialCursorValue=initialValue;
knobColor =c;
this.majorTick=majorTick;
this.minorTick=minorTick;
this.addMouseListener(this);
}
Knob (double initialValue, Color c, int majorTick, int minorTick, String title) {
//System.out.println("Knob");
cursorValue=initialCursorValue=initialValue;
knobColor =c;
this.majorTick=majorTick;
this.minorTick=minorTick;
this.title=title;
this.addMouseListener(this);
}
public void paintComponent (Graphics g) {
width=this.getWidth()/10*10;
height=this.getHeight()/10*10;
Graphics2D g2D = (Graphics2D)g;
System.setProperty("awt.useSystemAAFontSettings", "on");
System.setProperty("swing.aatext", "true");
g2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
if (width>height) {
length=height;
} else {
length=width;
}
centerX=width/2;
centerY=height/2;
g.setColor(Color.BLACK);
squareLength = (int )(length*0.9);
originX=(width-squareLength)/2;
originY=(height-squareLength)/2;
/*
//-45 = (-(Math.PI)/4)
angleOrigin= -45;
// 270 = (3*(Math.PI)/2)
angleRange=270;
//g.drawRect(originX, originY, squareLength, squareLength);
//g.fillArc(originX, originY, squareLength, squareLength, (int)angleOrigin, (int)angleRange);
for (int i=0; i<minorTick ; i++) {
angle=((i*angleRange/(minorTick-1))+angleOrigin)-7;
//System.out.println(angle*360/(2*Math.PI));
xTick= (int) (centerX+Math.cos(angle)*squareLength/2);
yTick= (int) (centerY-Math.sin(angle)*squareLength/2);
//g.drawLine(centerX, centerY, xTick, yTick);
//g.fillArc(originX, originY, squareLength, squareLength, (int)angle, (int)14);
}
*/
angleOrigin=-(Math.PI)/4;
angleRange=3*(Math.PI)/2;
g2D.setStroke(new BasicStroke(length/50+1));
for (int i=0; i<minorTick ; i++) {
angle=i*angleRange/(minorTick-1)+angleOrigin;
//System.out.println(angle*360/(2*Math.PI));
xTick= (int) (centerX+Math.cos(angle)*squareLength/2);
yTick= (int) (centerY-Math.sin(angle)*squareLength/2);
//g.drawLine(centerX, centerY, xTick, yTick);
g2D.draw (new Line2D.Float(centerX, centerY, xTick, yTick));
}
backgroundColor = this.getBackground();
g.setColor(backgroundColor);
diameter=(int)(length*0.8);
originX=(width-diameter)/2;
originY=(height-diameter)/2;
g.fillOval(originX, originY, diameter, diameter);
/*
RadialGradientPaint gp;
Point2D center= new Point2D.Float(width/2, height/2);
diameter=(int)(length*0.75);
originX=(width-diameter)/2;
originY=(height-diameter)/2;
float radius=diameter/2;
float[] dist = {0.7f, 1f};
Color[] colors = {Color.BLUE, Color.GRAY};
gp=new RadialGradientPaint(center, radius, dist, colors);
g2D.setPaint(gp);
g2D.fillOval(originX,originY,diameter,diameter);
*/
diameter=(int)(length*0.75);
originX=(width-diameter)/2;
originY=(height-diameter)/2;
g.setColor(Color.GRAY);
g.fillOval(originX,originY,diameter,diameter);
diameter=(int)(length*0.7);
originX=(width-diameter)/2;
originY=(height-diameter)/2;
g.setColor(knobColor);
g.fillOval(originX,originY,diameter,diameter);
g2D.setStroke(new BasicStroke(length/50+3));
angle=(2*Math.PI)*(0.75-cursorValue*0.75)+angleOrigin;
xCursor= (int) (centerX+Math.cos(angle)*length*0.35);
yCursor= (int) (centerY-Math.sin(angle)*length*0.35);
g.setColor(Color.GRAY);
g2D.draw (new Line2D.Float(centerX, centerY, xCursor, yCursor));
g2D.rotate(Math.toRadians(270.0));
g.setFont(new Font(g.getFont().getFontName(),Font.PLAIN,this.getHeight()/3));
titleWidth=g.getFontMetrics().stringWidth(title);
g2D.drawString(title,-this.getHeight()+titleWidth/3,this.getHeight()/4);
//System.out.println(titleWidth);
//System.out.println(this.getHeight()*(-70)/100+" - "+this.getHeight());
}
#Override
public void mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
//System.out.println("Bouton : "+arg0.getButton());
}
#Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
//System.out.println("Bouton : "+arg0.getButton());
PointerInfo pointer = MouseInfo.getPointerInfo();
Point mouseLocation = pointer.getLocation();
xMouseOrigin = (int) mouseLocation.getX();
yMouseOrigin = (int) mouseLocation.getY();
if (arg0.getButton()==MouseEvent.BUTTON1) {
mousePressed=true;
t= new Thread(new TrackPosition());
t.start();
} else if (arg0.getButton()==MouseEvent.BUTTON3) {
cursorValue=initialCursorValue;
repaint();
knobValue=cursorValue;
}
}
#Override
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
mousePressed=false;
//System.out.println("Mouse released");
repaint();
}
class TrackPosition implements Runnable {
#Override
public void run() {
// TODO Auto-generated method stub
while (mousePressed==true) {
PointerInfo pointer = MouseInfo.getPointerInfo();
Point mouseLocation = pointer.getLocation();
yMouse = (int) mouseLocation.getY();
yDeltaMouse=(float)(yMouse-yMouseOrigin)/100;
cursorValue=cursorValue+yDeltaMouse;
yMouseOrigin=yMouse;
if (cursorValue >=1) {
cursorValue=1;
} else if (cursorValue <= 0) {
cursorValue=0;
}
//This repaint is a problem if I "uncomment" it
repaint();
knobValue=cursorValue;
}
}
}
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
JFrame frame = new JFrame();
frame.setSize(300,70);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new Knob(0.5, new Color(0,255,0,255), 3, 9, "Gain"));
frame.setVisible(true);
}
}
You miss to call the paintComponent(Graphics g) method from JComponent.
Changing your code as below will solve the problem.
public void paintComponent(Graphics g) {
super.paintComponent(g);
I am creating a simple game where shapes fall and the player shoots them, but I am having problems creating bullet at every click of the mouse. I have tried various logic with no help, so am just going to put the code up here so you guys can take a look at it and help me out.
The bullet I created is not been created on every click just one is created and it moves on every click which is wrong........I want one bullet to be created per click.
// My main class: mousework2
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
import java.util.*;
import java.awt.geom.*;
public class mousework2 extends JFrame
{
public static int Width = 300;
public static int Height = 400;
private JPanel p1;
private Image pixMage,gunMage;
public mousework2()
{
super("shoot-em-up");
this.setSize(Width, Height);
this.setResizable(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Dimension pos = Toolkit.getDefaultToolkit().getScreenSize();
int x = (pos.width - Width) / 2;
int y = (pos.height - Height) / 2;
this.setLocation(x, y);
p1 = new CreateImage();
this.add(p1);
this.getContentPane();
Thread t = new recMove(this);
t.start();
}
class recMove extends Thread
{
JFrame b;
public recMove(JFrame b)
{
this.b = b;
}
public void run()
{
while (true) {
b.repaint();
try {
Thread.sleep(50);
} catch (InterruptedException e) {
}
}
}
}
class CreateImage extends JPanel implements MouseListener
{
ArrayList<fallShape> rect = new ArrayList<fallShape>();
int x_pos = mousework.Width / 2;
int y_pos = mousework.Height - 50;
int bx_pos = mousework.Width / 2;
int by_pos = mousework.Height;
int y_speed = -10;
boolean clicked;
public CreateImage()
{
for (int i = 0; i < 10; i++) {
rect.add(new fallShape(15, 15, rect));
}
Toolkit picx = Toolkit.getDefaultToolkit();
gunMage = picx.getImage("gunner.jpg");
gunMage = gunMage.getScaledInstance(200, -1, Image.SCALE_SMOOTH);
Toolkit pic = Toolkit.getDefaultToolkit();
pixMage = pic.getImage("ballfall3.jpg");
pixMage = pixMage.getScaledInstance(200, -1, Image.SCALE_SMOOTH);
addMouseListener(this);
addMouseMotionListener(new MouseMotionAdapter() {
#Override
public void mouseMoved(MouseEvent e)
{
x_pos = e.getX() - 5;
}
});
}
public void mousePressed(MouseEvent e)
{
if (e.getButton() == 1) {
clicked = true;
}
}
public void mouseReleased(MouseEvent e)
{
if (e.getButton() == 1) {
clicked = false;
}
}
public void mouseExited(MouseEvent e)
{
}
public void mouseEntered(MouseEvent e)
{
}
public void mouseClicked(MouseEvent e)
{
}
public void paint(Graphics g)
{
super.paint(g);
g.drawImage(pixMage, 0, 0, Width, Height, null);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.drawImage(gunMage,x_pos,y_pos,10,20,null);
if (clicked) {
by_pos += y_speed;
Shape bullet = new Rectangle2D.Float(bx_pos, by_pos, 3, 10);
g2.setColor(Color.BLACK);
g2.fill(bullet);
g2.draw(bullet);
}
g2.setColor(Color.RED);
for (fallShape b : rect) {
b.move();
g2.fill(b);
}
}
}
public static void main(String[] args)
{
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run()
{
new mousework2().setVisible(true);
}
});
}
}
And:
// My falling shapes class: fallShape
import java.awt.geom.*;
import java.util.*;
public class fallShape extends Rectangle2D.Float
{
public int x_speed, y_speed;
public int l, b;
public int height = mousework.Height;
public int width = mousework.Width;
public ArrayList<fallShape> fall;
public fallShape(int breadth, int length, ArrayList<fallShape> fall)
{
super((int) (Math.random() * (mousework.Width - 20) + 1), 0, breadth, length);
this.b = breadth;
this.l = length;
this.x_speed = (int) Math.random() * (10) + 1;
this.y_speed = (int) Math.random() * (10) + 1;
this.fall = fall;
}
public void move()
{
Rectangle2D rec = new Rectangle2D.Float(super.x, super.y, b, l);
for (fallShape f : fall) {
if (f != this && f.intersects(rec)) {
int rxspeed = x_speed;
int ryspeed = y_speed;
x_speed = f.x_speed;
y_speed = f.y_speed;
f.x_speed = rxspeed;
f.y_speed = ryspeed;
}
}
if (super.x < 0) {
super.x =+ super.x;
//super.y =+ super.y;
x_speed = Math.abs(x_speed);
}
if (super.x> mousework.Width - 30) {
super.x =+ super.x;
super.y =+ super.y;
x_speed =- Math.abs(x_speed);
}
if (super.y < 0) {
super.y = 0;
y_speed = Math.abs(y_speed);
}
super.x += x_speed;
super.y += y_speed;
}
}
if(clicked){
by_pos+=y_speed;
This code only draws the bullet when the mouse is down. This is because you are setting clicked to false in your mouseReleased method:
public void mouseReleased(MouseEvent e){
if(e.getButton()==1)
clicked=false;
}
If you were to remove the body of the mouseReleased method, your bullet would move properly.
However, say you wanted to have more than just one bullet. Currently, your paint method only draws one bullet at a time. To draw multiple bullets, you would need to create a list of the coordinates of the bullets, and add a new coordinate pair to the list whenever you click. Then, in the paint method, just update each position in a for loop.
ArrayList<Integer> by_poss = new ArrayList<>();
by_poss is the list of all the y-positions of your bullets.
public void mousePressed(MouseEvent e){
if(e.getButton() == 1)
by_poss.add(mousework.Height);
}
The mousePressed method adds a new "bullet", in the form of a y-position, to the coordinates.
public void mouseReleased(MouseEvent e){
//do nothing
}
Nothing needs to happen in the mouseReleased method.
//update the bullets
public void paint(Graphics g){
...
g2.setColor(Color.BLACK);
Shape bullet;
for(int i = 0; i < by_poss.size(); i++){
by_poss.set(i, by_poss.get(i) + y_speed); //move the bullet
bullet = new Rectangle2D.Float(bx_pos, by_poss.get(i), 3, 10);
g2.fill(bullet);
g2.draw(bullet);
}
...
}
The for loop in your paint method draws all the bullets, one by one, usin g the y-positions from the by_poss list.