I'm trying to get a ball to follow my mouse. The ball is supposed to move at a constant speed.

Edward_Gao

PVector location = new PVector();
PVector velocity = new PVector();

void setup() {
  size(1024, 576);
}

void draw() {
  background(0);
  PVector mouse = new PVector(mouseX, mouseY);

  mouse.sub(location);
  velocity.x = mouse.x / (mouse.x + mouse.y);
  velocity.y = mouse.y / (mouse.x + mouse.y);

  location.add(velocity);

  fill(255);
  ellipse(location.x, location.y, 40, 40);
}

GoToLoop

https://forum.Processing.org/two/discussion/15473/readme-how-to-format-code-and-text

1. http://studio.SketchPad.cc/sp/pad/view/ro.9XkJm3bjTAxB2/latest
2. http://studio.SketchPad.cc/sp/pad/view/ro.90vdKMfkiO$zf/latest
3. http://studio.SketchPad.cc/sp/pad/view/ro.9GTDpA6dp4tH1/latest

Edward_Gao

Sorry for my code. It's wrong anyways. To get my speed to always be constant, do i have to use the rotate function?

Lord_of_the_Galaxy

Read The Nature of Code from Daniel Shiffman. It will help a lot.

randomqweasdzxc

following what @Lord_of_the_Galaxy answered; you should search Daniel Shiffman's tutorials and book, if you are interested. As a direct answer I made the following code, referring to this shiffman.youtube video, it creates a new force PVector acceleration and uses that as variables for movement instead:

//velocity.x = mouse.x / (mouse.x + mouse.y); //removed
PVector acceleration = new PVector(); //created and set relations
acceleration = mouse;
velocity.add(acceleration); 
// and limit them.. mouse.mag and velocity.limit

full version, hope it helps:

PVector location = new PVector();
PVector velocity = new PVector();
PVector acceleration = new PVector();

void setup() {
  size(800, 600);
}

void draw() {
  background(0);
  PVector mouse = new PVector(mouseX, mouseY);
  mouse.sub(location);
  mouse.setMag(0.5);
  acceleration = mouse;
  velocity.add(acceleration);
  location.add(velocity);
  velocity.limit(7);
  fill(255);
  stroke(255);
  ellipse(location.x, location.y, 40, 40);
}