I'm working on a project where we are supposed to have rectangles of random sizes bounce off a wall and change color each time they bounce.
When you click on them, they are supposed to freeze in place and turn red. I'm just having trouble having them stop and for some reason they slow when one is clicked.
import java.util.Random;
public class Main {
public static void main(String[] args) {
MovingRectangles[] rectangles = new MovingRectangles[5];
Random rng = new Random();
for (int i = 0; i < rectangles.length; i++) {
rectangles[i] = new MovingRectangles(rng.nextDouble(), rng.nextDouble(), rng.nextDouble(), rng.nextDouble(), rng.nextDouble(), rng.nextDouble());
}
for (int g = 0; g < rectangles.length; g++) {
rectangles[g] = new MovingRectangles(
rng.nextDouble(),
rng.nextDouble(),
rng.nextDouble() / 50 - 0.01,
rng.nextDouble() / 50 - 0.01,
rng.nextDouble() * 0.04 + 0.03,
rng.nextDouble() * 0.04 + 0.03
);
}
while (true) {
StdDraw.clear();
for (int h = 0; h < rectangles.length; h++) {
rectangles[h].draw();
rectangles[h].update();
}
int count = 0;
for (int i =0; i < rectangles.length; i++) {
rectangles[i].draw();
if (StdDraw.mousePressed() && rectangles[i].containsPoint(StdDraw.mouseX(), StdDraw.mouseY())) {
rectangles[i].freeze();
}
if (rectangles[i].isFrozen()) {
count++;
StdDraw.show(25);
}
}
}
}}
This is the class for moving rectangles. Stackoverflow says I need to add context to explain what this code is.
import java.util.Random;
public class MovingRectangles {
private double x;
private double y;
private double vx;
private double vy;
private double hx;
private double hy;
private boolean isFrozen;
private int red;
private int green;
private int blue;
public MovingRectangles(double x, double y, double vx, double vy, double hx, double hy) {
this.x = x;
this.y = y;
this.vx = vx;
this.vy = vy;
isFrozen = false;
this.hx = hx;
this.hy = hy;
randomColor();
}
public void randomColor() {
Random rng = new Random();
red = rng.nextInt(256);
blue = rng.nextInt(256);
green = rng.nextInt(256);
}
public void draw() {
if (isFrozen) {
StdDraw.setPenColor(StdDraw.RED);
} else {
StdDraw.setPenColor(red, green, blue);
}
StdDraw.filledRectangle(x, y, hx, hy);
}
public void update() {
x += vx;
y += vy;
if (x - hx < 0) {
vx *= -1;
x = 0 + hx;
randomColor();
}
if (x + hx > 1) {
vx *= -1;
x = 1 - hx;
randomColor();
}
if (y - hy < 0) {
vy *= -1;
y = 0 + hy;
randomColor();
}
if (y + hy > 1) {
vy *= -1;
y = 1 - hy;
randomColor();
}
}
public void freeze() {
isFrozen = true;
}
public boolean isFrozen() {
return isFrozen;
}
public boolean containsPoint(double a, double b) {
return
a > x - hx &&
a < x + hx &&
b > y - hy &&
b < y + hy;
}
}
The only other thing I need to add is for it to print "You Win" when all five of the boxes have been clicked. thanks for any help.
My thought is that you're not stopping the actual update of the rectangle.
In your MovingRectangles class...
public void update() {
if(!this.isFrozen) {
{...your code...}
}
}
add at the very beginning of update method line like
if(isFrozen) return;
it should stop your rectangle.
the another way (if you don't want to touch rectangle class).
after
for (int h = 0; h < rectangles.length; h++) {
rectangles[h].draw();
add
if(!rectangles[h].isFrozen()) rectangles[h].update();
This update to draw fixed the problem I was having.
public void draw() {
if (isFrozen) {
StdDraw.setPenColor(StdDraw.RED);
StdDraw.filledRectangle(x, y, hx, hy);
vx = 0;
vy = 0;
} else {
StdDraw.setPenColor(red, green, blue);
}
StdDraw.filledRectangle(x, y, hx, hy);
}
Related
So I am doing circle to circle collision in java. I am aware that there are many similiar questions like mine on this website but my problem is unique from all of them. When I run my code, the circle's collide with each other once every 4 times. Meaning: 3 times they will go through without colliding with one another but one time they will collide. Any help is greatly appreciated.
public class Ball {
float x, y; // coordinates of ball rectangle
float xo, yo;
float vx = 2, vy = 2; // coordinates of velocity vector
Color colour; // ball colour
float d; // diameter of the ball or sizes of ball rectangle
Ellipse2D.Float circle;
// overloaded constructor
Ball(int x, int y, int vx, int vy, int d, Color colour) {
this.x = x;
this.y = y;
this.d = d;
xo = x;
yo = y;
this.setColour(colour);
this.setVelocity(vx, vy);
circle = new Ellipse2D.Float(x, y, d, d);
}
public void setColour(Color colour) {
this.colour = colour;
}
public void setVelocity(int vx, int vy) {
this.vx = vx;
this.vy = vy;
}
public void show(Graphics g) {
((Graphics2D) g).setPaint(colour);
circle.setFrame(x, y, d, d);
((Graphics2D) g).fill(circle);
xo = x;
yo = y;
}
public void hide(Graphics g) {
Color c = ((Graphics2D) g).getBackground();
((Graphics2D) g).setPaint(c);
circle.setFrame(xo, yo, d, d);
((Graphics2D) g).fill(circle);
}
public void setPosition(float x, float y) {
this.x = x;
this.y = y;
}
public void move(int a, int b, int xh, int yh) {
if (vy > 0) {
if (y + d + vy - yh - b > 0) {
y = yh + b - d;
vy = -vy;
} else
y += vy;
} else {
if (y + vy <= b) {
y = b;
vy = -vy;
} else
y += vy;
}
if (vx > 0) {
if (x + d + vx - xh - a > 0) {
x = xh + a - d;
vx = -vx;
} else
x += vx;
} else {
if (x + vx <= a) {
x = a;
vx = -vx;
} else
x += vx;
}
}
The Collision Detector is in the class below
public class Game extends JFrame {
int ah, bh, xh, yh; // parameters of the rectangle frame
Color[] ColorAr = { Color.red, Color.blue, Color.pink, Color.green,
Color.yellow, Color.magenta, Color.black, Color.orange, Color.gray,
Color.cyan };
Ball b[];
int quantity = 4;
public void paint(Graphics g) {
int i;
((Graphics2D) g).setPaint(Color.black);
((Graphics2D) g).drawRect(ah, bh, xh, yh);
for (i = quantity - 1; i >= 0; i--) {
b[i].hide(g);
}
for (i = 0; i < quantity; i++) {
b[i].show(g);
}
}
public void prepare() {
int i;
ah = 20;
bh = 40;
xh = 400;
yh = 400;
b = new Ball[quantity];
for (i = 0; i < quantity; i++) {
b[i] = new Ball((int) (Math.random() * (300 - 1 + 1)) + 1, 100, 1,
1, 26, ColorAr[(int) (Math.random() * 9)]);
}
}
public void collision() {
int radius = 13;
int distance = 2 * radius;
if (b[1].x + distance == b[0].x && b[1].y == b[0].y
|| b[1].x - distance == b[0].x && b[1].y == b[0].y) {
b[1].vx = -b[1].vx;
b[0].vx = -b[0].vx;
}
}
public void run() {
int i;
while (true) {
for (i = 0; i < quantity; i++)
b[i].move(ah, bh, xh, yh);// move balls
collision();
for (int j = 0; j < 10000000; j++)
; // delay;
// collision();
repaint();
}
}
public static void main(String args[]) {
Game frame = new Game();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// frame.setBackground(Color.white);
frame.setSize(450, 470);
frame.prepare();
frame.setVisible(true);
frame.run();
}
}
For two circles:
First calculate the sum of lengths: radius_1 + radius_2 (the first and the second circle).
Collision of two circles can be detected if you calculate the length of (imaginary) line between centers. If THAT length <= radius_1 + radius_2, two circles are colliding.
I'm trying to create a Roomba program with a ball that bounces around the screen that cleans the tiles that it passes over. The program should start with all grey tiles and when the ball passes over them then the tiles turn white. Currently I have the ball that bounces around everywhere and a grid method which creates a 5x5 grid.
I have encountered two problems:
I cannot make the grid and the ball appear in the same simulation while running the program, it's either one or the other.
I'm having trouble with finding a way to analyze if the ball has passed over certain squares in the grid, perhaps I need to create an object for the grid/ball?
My code:
import edu.princeton.cs.introcs.StdDraw;
public class Roomba {
private static int windowWidth = 200;
private static int windowHeight = 200;
private static double x = 100;
private static double y = 100;
private static double vx = 2;
private static double vy = 4;
private static int radius = 5;
private static boolean inGame = true;
public static void updateLocations() {
x += vx;
y += vy;
}
public static void drawGrid() {
StdDraw.setScale(0, 5);
int[][] grid = new int[5][5];
for (int x = 0; x < grid.length; x++) {
for (int y = 0; y < grid.length; y++) {
grid[x][y] = 255;
}
}
for (int x = 0; x < grid.length; x++) {
for (int y = 0; y < grid.length; y++) {
StdDraw.square(x, y, 1);
}
}
}
public static void updateVelocities() {
if (y + radius >= windowHeight) {
vy = -vy;
} else if (y - radius <= 0) {
vy = -vy;
}
if (x >= 194 || x <= 6) {
vx = -vx;
}
}
public static void setBackground() {
StdDraw.clear(StdDraw.GRAY);
// drawGrid();
}
public static void drawBall() {
StdDraw.setPenColor(StdDraw.BLACK);
StdDraw.filledCircle(x, y, radius);
// StdDraw.setPenColor(StdDraw.RED);
// StdDraw.filledSquare(x + 3, y + 3, 1);
StdDraw.setPenColor(StdDraw.BLACK);
StdDraw.text(100, 70, "x is: " + x + " y is: " + y);
}
public static void draw() {
setBackground();
drawBall();
}
public static void main(String[] args) {
StdDraw.setCanvasSize(800, 800);
StdDraw.setXscale(0, windowWidth);
StdDraw.setYscale(0, windowHeight);
while (true) {
if (inGame) {
draw();
updateVelocities();
updateLocations();
} else {
StdDraw.text(100, 100, "Game Over");
}
// change to if all tiles have been cleaned
// if (x + radius > windowWidth || x - radius < 0) {
// inGame = false;
// }
StdDraw.show(20);
}
}
}
Maybe the background is being drawn over the ball or vice verse? Try to draw the ball first then the background? Make sure the ball is actually being rendered at the correct size and not as the entire screen. I'm not to familiar with 2D graphics but maybe there is some z fighting?
I am making a game in java and I have most of it done. However, one of the last bugs i need to fix is that enemy sprites can overlap each other and spawn on top of one another off screen. I want to make it so if enemy sprites collide they can only touch but not overlap. here is the code for the enemy class.
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Rectangle;
import java.util.ArrayList;
import javax.swing.ImageIcon;
public class Enemy extends Base {
int x;
int y;
int velx = -2;
int vely = 0;
public Enemy(int x, int y) {
super(x,y);
this.x = x;
this.y = y;
}
public void update() {
movement();
x += velx;
y += vely;
if (x < - 15) {
x = -15;
movement();
}
if (x > 1100) {
x = 1100;
movement();
}
if (y > 660) {
y = 660;
movement();
}
if (y < 10) {
y = 10;
movement();
}
}
public void draw(Graphics g) {
g.drawImage(getEnemyImage(), x, y, null);
}
public static Image getEnemyImage(){
ImageIcon ic = new ImageIcon("enemy.gif");
return ic.getImage();
}
public Rectangle getBounds(){
return new Rectangle(x, y, getEnemyImage().getWidth(null), getEnemyImage().getHeight(null));
}
public void checkColision(){
ArrayList<Base> enemies = GamePanel.getEnemyList();
if (x <= 0) {
velx = 2;
}
if (x >= 1096) {
velx = -2;
}
for (int a = 0; a < enemies.size(); a++) {
Base temp = GamePanel.enemy.get(a);
if (getBounds().intersects(temp.getBounds())) {
// where the collision check should happen.
}
}
}
public void movement(){
if (y > 16) {
if (x > GamePanel.p.getX()) {
velx = - 2;
}
if (x < GamePanel.p.getX()) {
velx = 2;
}
if (y > GamePanel.p.getY()) {
vely = -2;
}
if (y < GamePanel.p.getY()) {
vely = 2;
}
}
}
}
and this is where the enemies are spawned.
for (int a = 0; a < enemy_amount; a++) {
space += 50;
int rand = (int)(Math.random() * 2) + 1;
if (rand == 1) {
int randp = (int)(Math.random() * 2) + 1;
int x = 0;
int y = 0;
if (randp == 1) {
x = 1250 + space;
y = 500;
}
if (randp == 2) {
x = 1250 + space;
y = 100;
}
enemy.add(new Enemy(x,y));
}
if (rand == 2) {
int randp = (int)(Math.random() * 2) + 1;
int x = 0;
int y = 0;
if (randp == 1) {
x = 250;
y = -100 - space;
}
if (randp == 2) {
x = 850;
y = -100 - space;
}
enemy.add(new Enemy2(x,y));
}
}
any help would be great because i am really stuck.
I'm working my way through Daniel Shiffman's excellent The Nature of Code book and have completed simulating gravitational attraction and repulsion between objects.
The gravitational force works well, but my objects fly right off the screen. I would like to constrain them to the drawing canvas. I am using an edge-checking function written in the previous chapter, and it is failing to keep any objects on the canvas.
I would love to know why.
The offending function is the last block of code in the Mover class.
class Mover {
PVector location;
PVector velocity;
PVector acceleration;
float mass;
float G = 0.4; //universal gravitational constant
Mover(float m, float x, float y) {
location = new PVector(x,y);
velocity = new PVector(1,0);
acceleration = new PVector(0,0);
mass = m;
}
PVector attract(Mover m) {
PVector force = PVector.sub(location,m.location);
float distance = force.mag();
distance = constrain(distance,5,25);
force.normalize();
float strength = ((G * mass * m.mass) / (distance * distance)*-1);
force.mult(strength);
return force;
}
void applyForce(PVector force) {
PVector f = PVector.div(force,mass);
acceleration.add(f);
}
void update() {
velocity.add(acceleration);
location.add(velocity);
acceleration.mult(0);
}
void display() {
stroke(0);
strokeWeight(2);
fill(0,100);
ellipse(location.x,location.y, mass*25 , mass*25);
}
void checkEdges() { // why doesn't this work?
if (location.x > width) {
location.x = width;
velocity.x *= -1;
} else if (location.x < 0) {
velocity.x *= -1;
location.x = 0;
}
if (location.y > height) {
velocity.y *= -1;
location.y = height;
} else if (location.y < 0) {
velocity.y *= -1;
location.y = 0;
}
}
}
//////////////////////////////////////////////////////////////////////
Mover [] movers = new Mover [10];
void setup() {
size(1000,1000);
for (int i = 0; i < movers.length; i++) {
movers[i] = new Mover(random(0.1,2),random(width),random(height)); //mass, loc.x, loc.y //each mover initialized randomly
}
}
void draw() {
background(255);
for(int i = 0; i < movers.length; i++){
for(int j = 0; j < movers.length; j++){
if(i != j){
PVector force = movers[j].attract(movers[i]); //Calculate attraction force
movers[i].applyForce(force); //Apply attraction force
}
}
movers[i].update();
movers[i].display();
}
}
Shouldn't you be calling checkEdges() inside Update()? If not that, then how about in your main code between
movers[i].update();
movers[I].checkEdges(); // check after the update and before the display
movers[i].display();
You're not checking whether location.y is less than zero.
Compare what you're doing for X:
if (location.x > width) {
location.x = width;
velocity.x *= -1;
} else if (location.x < 0) {
velocity.x *= -1;
location.x = 0;
}
to what you're doing for Y:
if (location.y > height) {
velocity.y *= -1;
location.y = height;
}
I have an image inside the panel and it moves in a clockwise direction. Now, I want it to move in a random direction and that is my problem.
Could someone give me an idea how to do it?
Here's what I've tried :
private int xVelocity = 1;
private int yVelocity = 1;
private int x, y;
private static final int RIGHT_WALL = 400;
private static final int UP_WALL = 1;
private static final int DOWN_WALL = 400;
private static final int LEFT_WALL = 1;
public void cycle()
{
x += xVelocity;
if (x >= RIGHT_WALL)
{
x = RIGHT_WALL;
if (y >= UP_WALL)
{
y += yVelocity;
}
}
if (y > DOWN_WALL)
{
y = DOWN_WALL;
if (x >= LEFT_WALL)
{
xVelocity *= -1;
}
}
if (x <= LEFT_WALL)
{
x = LEFT_WALL;
if (y <= DOWN_WALL)
{
y -= yVelocity;
}
}
if (y < UP_WALL)
{
y = UP_WALL;
if (x <= RIGHT_WALL)
{
xVelocity *= -1;
}
}
}
Call a method like this to set a random direction:
public void setRandomDirection() {
double direction = Math.random()*2.0*Math.PI;
double speed = 10.0;
xVelocity = (int) (speed*Math.cos(direction));
yVelocity = (int) (speed*Math.sin(direction));
}
Just noticed that you're cycle method will need a little fixing for this to work.
public void cycle() {
x += xVelocity;
y += yVelocity; //added
if (x >= RIGHT_WALL) {
x = RIGHT_WALL;
setRandomDirection();//bounce off in a random direction
}
if (x <= LEFT_WALL) {
x = LEFT_WALL;
setRandomDirection();
}
if (y >= DOWN_WALL) {
y = DOWN_WALL;
setRandomDirection();
}
if (y <= UP_WALL) {
y = UP_WALL;
setRandomDirection();
}
}
(It works, but this is not the most efficient/elegant way to do it)
And if you want some sort of 'random walk' try something like this:
public void cycle() {
//move forward
x += xVelocity;
y += yVelocity;
if (Math.random() < 0.1) {//sometimes..
setRandomDirection(); //..change course to a random direction
}
}
You can increase 0.1 (max 1.0) to make it move more shaky.
Change
y -= yVelocity;
To
if (y>0) {
y = -1*Random.nextInt(3);
} else {
y = Random.nextInt(3);
}