Bouncing Throwable Ball

Processing Coding Questions
1

Hi all. I’ve made the basic bouncing ball, but I’m trying to make it so that it maintains the velocity of the cursor. is there something I did wrong?

PVector location;
PVector velocity;
PVector gravity;


int sz = 100;
color bgcolor;

void setup() {
  size (900, 700);
    location = new PVector(100, 100);
    velocity = new PVector(1.5, 2.1);
    gravity = new PVector(0, 0.2);
}

void draw() {
  background (#151515);
  //so i can see what i'm doing
  text("x: "+mouseX+" y: "+mouseY, 10, 15);
  
  //add velocity to location.
  location.add(velocity);
  //add gravity to velocity
  velocity.add(gravity);
  
    if (dist(location.x, location.y, mouseX, mouseY) < sz / 2) {
        cursor(HAND);
    
    if (mousePressed) {
      location.x = mouseX;
      location.y = mouseY;
      strokeWeight(5);
    } else {
      strokeWeight(2);
    }
    stroke(255);
  } else {
    cursor(ARROW);
    noStroke();
  }
  
  
  
  //bounce off edges
  if ((location.x > width) || (location.x < 0)) {
    velocity.x = velocity.x * -1;
  }
  if (location.y > height) {
    
    //reduce the velocity when it hits the bottom of the window
    velocity.y = velocity.y * -0.95; 
    location.y = height;
  }

  //the ball
  stroke(255);
  strokeWeight(2);
  fill(127);
    ellipse(location.x, location.y, 75, 75);

}
1 Like
2

I can’t see where you do this.

Can you tell me the lines in your code you are referring to please?

And welcome to the forum, a great community.

Regards, Chrisir

2 Likes
3

Hi! I’m happy to be here.

The problem is I can’t figure out how to do that. How would I go about this?

4

I understand that the faster you drag the mouse while holding the mouse button down (like drag and drop), the faster is the ball.

The way I see it you can measure the distance between the mouse and the previous mouse position

  • to measure a distance use dist

  • previous mouse position is pmouseX, pmouseY - see reference

  • during the mouse dragging we search the biggest distance. That’s the velocity (or the 10 fold of it or so)

That’s your starting point:


boolean hold=false; 
float biggest=-11111;

void setup() {
  size(1000, 600);
  background(200);
}

void draw() {
  background(200);

  if (hold) {
    float newValue=dist(mouseX, mouseY, pmouseX, pmouseY); 
    println(newValue);
    if (newValue>biggest) {
      biggest=newValue;
    }
  }

  fill(0);
  text(biggest, 33, 33);
}

//------------------------------------------------------------------

void mousePressed() {
  hold = true;
  biggest=-11111;
}

void mouseReleased() {
  hold = false;
}
3 Likes