This example is for Processing 3+. If you have a previous version, use the examples included with your software. If you see any errors or have suggestions, please let us know.


Move the cursor over the image to draw with a software tool which responds to the speed of the mouse.

void setup() {
  size(640, 360);

void draw() {
  // Call the variableEllipse() method and send it the
  // parameters for the current mouse position
  // and the previous mouse position
  variableEllipse(mouseX, mouseY, pmouseX, pmouseY);

// The simple method variableEllipse() was created specifically 
// for this program. It calculates the speed of the mouse
// and draws a small ellipse if the mouse is moving slowly
// and draws a large ellipse if the mouse is moving quickly 

void variableEllipse(int x, int y, int px, int py) {
  float speed = abs(x-px) + abs(y-py);
  ellipse(x, y, speed, speed);