Mouse collision with moving objects

Programming Questions

craig246

Mouse collision with moving objects

in Programming Questions • 1 year ago

Hey all,

I'm currently in the process of writing a maze-like game, where the player guides their mouse pointer through a course of thin lines and moving objects without touching anything.

I am getting hung up on the collision of the moving balls that the player must avoid. I have made them move and bounce successfully, but I cannot figure out how to write the collision between the mouse pointer and the balls.

Ideally, when the pointer and one of the balls collide, the boolean gameStart would be set back to false, but I don't know how to define the collision for each ball's x and y coordinates, as they are defined in a for-loop all at once. I have tried my hand at writing objects for the balls and collision, but I just can't make it work.

If anyone could please lend this beginner a hand in helping to write this segment of code, and explain what I would have to do to move forward, it would be very much appreciated! I am trying to learn as much as I can about Processing while working on this project, and I've been loving (mostly) every minute of it. Any feedback at all is helpful.

Replies(4)

PhiLho

Re: Mouse collision with moving objects

1 year ago

Ouch, using a Ball class would definitively help! You find if a point is close of another using dist() with the coordinates of the mouse and the center of the ball. If it is below the radius of the ball, there is a hit.

craig246

Re: Mouse collision with moving objects

1 year ago

Could you elaborate a bit on how I would change the ball drawing functions I have now into a class. I am not sure of where to start.

PhiLho

Re: Mouse collision with moving objects

1 year ago

Take a look at the Motion examples of Processing, or perhaps the From several variables to arrays article and the next one. If you are still stuck, ask again.

craig246

Re: Mouse collision with moving objects

1 year ago

Thanks for the article links, they were a great help and very informative.

After reading through the articles, I find that I understand a lot of what is going on by reading the code, but am having some trouble reproducing the results in my own programs.

To make things simple, I am going to try to make a separate program with the bouncing balls and mouse collision that I would need in my main program.

I have started with the Bouncing Bubbles example given in processing, but am adapting it to fit what I need. What I've started with is a bunch of balls that bounce within the desired area, but for some reason, as the program runs they do not stay in a line. Specifically, it looks like the first and second ball are the only issues, and I cannot figure out why.

Heres the code. Once again, any help is mucho appreciated!

int numBalls = 10;
int speed = 3;
int xPos = 20;
Ball[] balls = new Ball[numBalls];
void setup()
{
size(640, 200);
noStroke();
smooth();
for (int i = 0; i < numBalls; i++) {
balls[i] = new Ball(xPos, 40, 15, i);
xPos = xPos + 40;
}
}
void draw()
{
background(0);
for (int i = 0; i < numBalls; i++) {
balls[i].move();
balls[i].display();
}
}
class Ball {
float x, y;
float diameter;
int id;
Ball(float xin, float yin, float din, int idin) {
x = xin;
y = yin;
diameter = din;
}
void move() {
y = y + speed;
if (y > height - diameter/2) {
speed = speed*-1;
}
else if (y < 0 + diameter/2) {
speed = speed*-1;
}
}
void display() {
fill(255);
ellipse(x, y, diameter, diameter);
}
}

Edit: Fixed the issue myself and got the collision working. Thanks for the help Phil!

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