# Bouncing Throwable Ball
**URL:** https://discourse.processing.org/t/bouncing-throwable-ball/15429
**Category:** Coding Questions
**Created:** [November 12, 2019, 7:44pm UTC](https://discourse.processing.org/t/bouncing-throwable-ball/15429 "2019-11-12T19:44:11Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@riverhawc](https://discourse.processing.org/u/riverhawc)
#### Post date: [November 12, 2019, 7:44pm UTC](https://discourse.processing.org/t/bouncing-throwable-ball/15429/1 "2019-11-12T19:44:11Z")
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?
```auto
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);
}
```
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [November 12, 2019, 8:07pm UTC](https://discourse.processing.org/t/bouncing-throwable-ball/15429/2 "2019-11-12T20:07:37Z")
> [@riverhawc](#):
>
> make it so that it maintains the velocity of the cursor.
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
---
### Author:  [@riverhawc](https://discourse.processing.org/u/riverhawc)
#### Post date: [November 12, 2019, 8:14pm UTC](https://discourse.processing.org/t/bouncing-throwable-ball/15429/3 "2019-11-12T20:14:21Z")
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?
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [November 12, 2019, 8:25pm UTC](https://discourse.processing.org/t/bouncing-throwable-ball/15429/4 "2019-11-12T20:25:09Z")
> [@Chrisir](#):
>
> make it so that it maintains the velocity of the cursor.
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:**
```auto
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;
}
```