Please Please Help with Projectile Project Here are the Codes

Question

I've got three(3) classes a Model, a view, and a controller.
This is a project about projectiles.it is an animation of a cannonball being fired from a cannon and travelling under the effect of gravity.A cannon fired at angle 'a' to the horizontal and with an initial speed 's', will have an initial velocity given by:
vx := s * cos(a);//velocity x equals the speed multiply by the cosine of angle a.
vy := s * sin(a);//velocity y equals the speed multiply by the sine of angle a.
Here are the code.
Model:
/** Cannon specifies the expected behaviour of a cannon*/
public class Cannon{
public static final int TICK = 60;
private int velocity = 0;
private static final double gravity = .098f;
private double angle = 0;
// distances & positions are meausred in pixels
private int x_pos; // ball's center x-position
private int y_pos; // ball's center y-position
// speed is measured in pixels per `tick'
private int x_velocity; // horizonal speed; positive is to the right
private int y_velocity; // vertical speed; positive is downwards
public Cannon() {
velocity = 3;
angle = 60;
angle = radians(angle);
x_pos = 0;
y_pos = 385;
/** shoot fires a shot from the cannon*/
public void shoot(){
move();
/**reload reloads the cannon with more shorts*/
public void reload() {
/** changeAngle changes the angle of the canon
* @params value - the amount to add or subtract from the current angle value*/
public void changeAngle(double value) {
angle = (double)value;
angle = radians(angle);
/** getAngle returns the current angle value of the cannon*/
public double getAngle() {
return angle;
/** changeVelocity changes the speed at which a cannon ball that is to be fire will travel at
* @params value - the new speed at which the user wants a cannon ball to travel at.*/
public void changeVelocityX(int value){
x_velocity = x_velocity * (int)Math.cos(value);
public void changeVelocityY(int value){
y_velocity = y_velocity * (int)Math.sin(value);
/** getVelocity returns the current velocity value of the cannon*/
public int getVelocityX() {
return x_velocity;
public int getVelocityY() {
return y_velocity;
/** getGravity returns the current gravity value of the cannon*/
public double getGravity() {
return gravity;
public int xPosition(){
return x_pos;
public int yPosition(){
return y_pos;
public void move(){
double dx = getVelocityX() * Math.cos(getAngle());
double dy = getVelocityY() * Math.sin(getAngle());
x_pos+=dx;
y_pos-=dy;
double radians (double angle){
return ((Math.PI * angle) / 180.0);
View:
import java.awt.*;
import javax.swing.*;
/** CannonView displays a cannon being fired.*/
public class CannonView extends JPanel{
/** DISPLAY_SIZE specifies the overall display area of the cannon and the bucket.*/
public static final int DISPLAY_AREA_SIZE = 600;
public RotatablePolygon rectangle;
public RotatablePolygon triangle;
public Cannon cannon;
public CannonView(Cannon c) {
this.setPreferredSize(new Dimension(600,450));
this.setBackground(Color.black);
cannon = c;
int xRectangle[] = {0,0,40,40,0};
int yRectangle[] = {400,300,300,400,400};
int xTriangle[] = {0,20,40,0};
int yTriangle[] = {300,280,300,300};
rectangle = new RotatablePolygon (xRectangle, yRectangle, 5,20,350);
// rectangle.setPosition (100, 100);
// triangle = new RotatablePolygon (xTriangle, yTriangle, 4,0,290);
triangle = new RotatablePolygon (xTriangle, yTriangle, 4,20,350);
//triangle.setPosition (100, 100);
JFrame frame = new JFrame();
frame.getContentPane().add(this);
frame.pack();
frame.setVisible(true);
frame.setTitle("Width = " + frame.getWidth() + " , Height = " + frame.getHeight());
/** drawBucket draws a bucket/target for which a moving cannon ball should hit.
* @param g - the graphics pen for which the drawing should occur.*/
public void drawBucket(Graphics g) {
g.setColor(Color.red);
int xvalues[] = {495, 519, 575, 595, 495};
int yvalues[] = {340, 400, 400, 340, 340};
Polygon poly1 = new Polygon (xvalues, yvalues, 5);
g.fillPolygon(poly1);
g.setColor(Color.white);
g.fillOval(495, 328, 100, 24);
Graphics2D g2d = (Graphics2D)g;
g2d.setStroke(new BasicStroke(2));
g.setColor(Color.red);
g.drawOval(495, 328, 100, 24);
g.drawOval(495,311,100,54);
/** drawCannon draws a cannon
* @param g - the graphics pen that will be used to draw the cannon.*/
public void drawCannon(Graphics g) {
Graphics2D g2 = (Graphics2D)g;
g.setColor(Color.red);
g2.fill(rectangle);
g.setColor(Color.orange);
g2.fill(triangle);
g.setColor(Color.blue);
g.fillOval(95, 340, 60, 60);
g.setColor(Color.magenta);
for (int i = 0; i < 6; i++){
g.fillArc(95, 340, 60, 60, i* 60, 30);
g.setColor(Color.black);
g.fillOval(117, 362, 16, 16);
/** drawCannonShots will draw the actual number of shots already used by the cannon
* @param g - the graphics pen that will be used to draw the shots of the cannon.*/
public void drawCannonShots(Graphics g) {
g.setColor(Color.orange);
g.fillOval(cannon.xPosition(),cannon.yPosition(),16,16);
/** drawTrail will draw a trail of smoke to indicate where a cannon ball has passed
* @param g - the graphics pen used to draw the trail.*/
public void drawTrail(Graphics g){}
/**drawGround draws the ground for which the cannon sits*/
public void drawGround(Graphics g) {
g.setColor(Color.green.brighter());
g.fillRect(0,400,600,50);
/** drawMovingCannonBall draw a cannon ball moving at a certain speed (velocity),
* with a certain amount of gravitational acting upon it, at a certain angle.
* @params g - the graphics pen used to draw the moving cannon ball.
* @params gravity - the value of gravity.
* @params velocity - the speed at which the ball is travelling.
* @params angle - the angle at which the ball was shot from.*/
public void drawMovingCannonBall(Graphics g, double gravity, double velocity, double angle){}
/** paintComponent paints the cannon,bucket
* @param g - graphics pen.*/
public void paintComponent(Graphics g) {
super.paintComponent(g);
drawGround(g);
drawBucket(g);
drawCannon(g);
drawCannonShots(g);
Controller
/** CannonController controls the interaction between the user and a cannon*/
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class CannonController extends JFrame{
public JMenuBar jMenuBar2;
public JMenu jMenu2;
public JMenuItem jMenuItem1;
public JMenu jMenu3;
public JMenuItem jMenuItem2;
public JLabel angleLabel, velocityLabel;
public JTextField angleTextField, velocityTextField;
public JButton fireButton, reloadButton;
public JSlider angleSlider, velocitySlider;
private CannonView view;
private Cannon cannon;
int oldValue, newValue;
public CannonController(Cannon acannon) {
cannon = acannon;
view = new CannonView(cannon);
loadControls();
angleTextField.setText(String.valueOf(angleSlider.getValue()));
oldValue = angleSlider.getValue();
newValue = oldValue + 1;
velocityTextField.setText(String.valueOf(velocitySlider.getValue()));
this.setSize(328,308);
this.setLocation(view.getWidth()-this.getWidth(),0);
/** loadControl loads all of the GUI controls that a
* user of the cannon animation will use to interact with the program*/
public void loadControls() {
jMenuBar2 = new JMenuBar();
jMenu2 = new JMenu();
jMenuItem1 = new JMenuItem();
jMenu3 = new JMenu();
jMenuItem2 = new JMenuItem();
angleLabel = new JLabel();
velocityLabel = new JLabel();
angleTextField = new JTextField();
velocityTextField = new JTextField();
fireButton = new JButton();
reloadButton = new JButton();
angleSlider = new JSlider();
velocitySlider = new JSlider();
jMenuBar2.setBorderPainted(false);
jMenu2.setModel(jMenu2.getModel());
jMenu2.setText("File");
jMenuItem1.setText("Exit");
jMenuItem1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jMenuItem1ActionPerformed(evt);
jMenu2.add(jMenuItem1);
jMenuBar2.add(jMenu2);
jMenu3.setText("Help");
jMenuItem2.setText("About this Program");
jMenuItem2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jMenuItem2ActionPerformed(evt);
jMenu3.add(jMenuItem2);
jMenuBar2.add(jMenu3);
getContentPane().setLayout(null);
setTitle("Cannon Controller Form");
setResizable(false);
setMenuBar(getMenuBar());
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent evt) {
exitForm(evt);
angleLabel.setText("Angle:");
getContentPane().add(angleLabel);
angleLabel.setLocation(10, 20);
angleLabel.setSize(angleLabel.getPreferredSize());
velocityLabel.setText("Velocity:");
getContentPane().add(velocityLabel);
velocityLabel.setLocation(10, 80);
velocityLabel.setSize(velocityLabel.getPreferredSize());
angleTextField.setToolTipText("Only numeric values are allow");
getContentPane().add(angleTextField);
angleTextField.setBounds(280, 20, 30, 20);
velocityTextField.setToolTipText("Only numeric values are allow");
getContentPane().add(velocityTextField);
velocityTextField.setBounds(280, 80, 30, 20);
fireButton.setToolTipText("Click to fire a shot");
fireButton.setText("Fire");
fireButton.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent evt) {
fireButtonMouseClicked(evt);
getContentPane().add(fireButton);
fireButton.setBounds(60, 160, 80, 30);
reloadButton.setToolTipText("Click to reload cannon");
reloadButton.setText("Reload");
reloadButton.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent evt) {
reloadButtonMouseClicked(evt);
getContentPane().add(reloadButton);
reloadButton.setBounds(150, 160, 80, 30);
angleSlider.setMinorTickSpacing(30);
angleSlider.setPaintLabels(true);
angleSlider.setPaintTicks(true);
angleSlider.setMinimum(0);
angleSlider.setMajorTickSpacing(60);
angleSlider.setToolTipText("Change the cannon angle");
angleSlider.setMaximum(360);
angleSlider.setValue(0);
angleSlider.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent evt) {
angleSliderStateChanged(evt);
getContentPane().add(angleSlider);
angleSlider.setBounds(60, 20, 210, 40);
velocitySlider.setMinorTickSpacing(5);
velocitySlider.setPaintLabels(true);
velocitySlider.setPaintTicks(true);
velocitySlider.setMinimum(1);
velocitySlider.setMajorTickSpacing(10);
velocitySlider.setToolTipText("Change the speed of the cannon ball");
velocitySlider.setMaximum(28);
velocitySlider.setValue(3);
velocitySlider.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent evt) {
velocitySliderStateChanged(evt);
getContentPane().add(velocitySlider);
velocitySlider.setBounds(60, 80, 210, 50);
setJMenuBar(jMenuBar2);
pack();
private void reloadButtonMouseClicked(MouseEvent evt) {
reloadButtonClick();
private void fireButtonMouseClicked(MouseEvent evt) {
fireButtonClick();
/** firstButtonClick is the event handler that sends a message
* to the cannon class to invokes the cannon's fire method*/
public void fireButtonClick() {
// JOptionPane.showMessageDialog(null,"You click Fire");
cannon.shoot();
view.repaint();
/** reloadButtonClick is the event handler that sends a message
* to the cannon class to invokes the cannon's reload method*/
public void reloadButtonClick() {
JOptionPane.showMessageDialog(null,"reload");
private void angleSliderStateChanged(ChangeEvent evt) {
angleTextField.setText(String.valueOf(angleSlider.getValue()));
view.rectangle.setAngle(angleSlider.getValue() * (Math.PI / 180));
view.triangle.setAngle(angleSlider.getValue() * (Math.PI / 180));
cannon.changeAngle(angleSlider.getValue());
view.repaint();
private void velocitySliderStateChanged(ChangeEvent evt) {
velocityTextField.setText(String.valueOf(velocitySlider.getValue()));
cannon.changeVelocityX(velocitySlider.getValue());
private void gravitySliderStateChanged(ChangeEvent evt) {
private void jMenuItem1ActionPerformed(ActionEvent evt) {
System.exit (0);
private void jMenuItem2ActionPerformed(ActionEvent evt) {
String message = "Cannon Animation\n"+
"Based on the Logic of Projectiles";
JOptionPane.showMessageDialog(null,message,"About this program",JOptionPane.PLAIN_MESSAGE);
/** Exit the Application */
private void exitForm(WindowEvent evt) {
System.exit (0);
/** Pause execution for t milliseconds. */
private void delay (int t) {
try {
Thread.sleep (t);
} catch (InterruptedException e) {}
public static void main(String [] args){
Cannon cn = new Cannon();
CannonController control = new CannonController(cn);
control.setTitle("Test");
control.setVisible(true);
if the cannon ball land in the bucket it should stop and the animation should indicate a 'hit' in some way. maybe by displaying a message.
if the cannonball hits the outside of the bucket it should bounce off.
Extra Notes.
1) The acceleration due to gravity is 9.8m/s to the (power of (2) eg s2.
2) The distance travelled in time t by a body with initial velocity v under constant acceleration a is:
v * t + a * t.pow(2) div 2;
The velocity at the end of time t will be v + a * t.
Distance is measure in pixels rather than meter so for simplicity we use 1 pixel per meter
When i pressed the fire button nothings happens. I'm going crazy. Please please help!

Answer 1

Here is the interface specification for the RotatablePolygon class. I do not have the actual .java source.
Thanks
Class RotatablePolygon
java.lang.Object
|
--java.awt.geom.Area
|
--RotatablePolygon
All Implemented Interfaces:
java.lang.Cloneable, java.awt.Shape
public class RotatablePolygon
extends java.awt.geom.Area
Polygons which can be rotated around an `anchor' point and also translated (moved in the x and y directions).
Constructor Summary
RotatablePolygon(int[] xs, int[] ys, int n, double x, double y)
Create a new RotatablePolyogon with given vertices and anchor point (x,y).
Method Summary
double getAngle()
The current angle of rotation.
double getXanchor()
x-coordinate of the anchor point.
double getYanchor()
y-coordinate of the anchor point.
void rotate(double da)
Rotate the polygon from its current position by angle da (in radians) around the anchor.
void rotateDegrees(double da)
Rotate the polygon from its current position by angle da (in degrees) around the anchor.
void setAngle(double a)
Set the angle of rotation of the polygon to be angle a (in radians) around the anchor.
void setAngleDegrees(double a)
Set the angle of rotation of the polygon to be angle a (in degrees) around the anchor.
void setPosition(double x, double y)
Shift the polygon's position to put its anchor point at (x,y).
void translate(double dx, double dy)
Shift the polygon's position and anchor point by given amounts.
Methods inherited from class java.awt.geom.Area
add, clone, contains, contains, contains, contains, createTransformedArea, equals, exclusiveOr, getBounds, getBounds2D, getPathIterator, getPathIterator, intersect, intersects, intersects, isEmpty, isPolygonal, isRectangular, isSingular, reset, subtract, transform
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
RotatablePolygon
public RotatablePolygon(int[] xs,
int[] ys,
int n,
double x,
double y)
Create a new RotatablePolyogon with given vertices and anchor point (x,y).
REQUIRE: xs.length >= n && ys.length >= n
Parameters:
xs - x-coordinates of vertices
ys - y-coordinates of vertices
n - number of vertices
x - x-coordinate of the rotation anchor
y - y-coordinate of the rotation anchor
Method Detail
setPosition
public void setPosition(double x,
double y)
Shift the polygon's position to put its anchor point at (x,y).
Parameters:
x - new x-coordinate for anchor point
y - new y-coordinate for anchor point
translate
public void translate(double dx,
double dy)
Shift the polygon's position and anchor point by given amounts.
Parameters:
dx - amount to shift by in x-direction
dy - amount to shift by in y-direction
setAngle
public void setAngle(double a)
Set the angle of rotation of the polygon to be angle a (in radians) around the anchor.
Parameters:
a - angle to rotate to, in radians
setAngleDegrees
public void setAngleDegrees(double a)
Set the angle of rotation of the polygon to be angle a (in degrees) around the anchor.
Parameters:
a - angle to rotate to, in degrees
rotate
public void rotate(double da)
Rotate the polygon from its current position by angle da (in radians) around the anchor.
Parameters:
da - angle to rotate by, in radians
rotateDegrees
public void rotateDegrees(double da)
Rotate the polygon from its current position by angle da (in degrees) around the anchor.
Parameters:
da - angle to rotate by, in degrees
getAngle
public double getAngle()
The current angle of rotation.
getXanchor
public double getXanchor()
x-coordinate of the anchor point.
getYanchor
public double getYanchor()
y-coordinate of the anchor point.