processing4/java/examples/Topics/Drawing/Pattern/applet/Pattern.java

import processing.core.*; 

import java.applet.*; 
import java.awt.*; 
import java.awt.image.*; 
import java.awt.event.*; 
import java.io.*; 
import java.net.*; 
import java.text.*; 
import java.util.*; 
import java.util.zip.*; 
import java.util.regex.*; 

public class Pattern extends PApplet {

/**
 * Patterns. 
 * 
 * Move the cursor over the image to draw with a software tool 
 * which responds to the speed of the mouse. 
 */
 
public void setup()
{
  size(640, 360);
  background(102);
  smooth();
}

public 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 

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

  static public void main(String args[]) {
    PApplet.main(new String[] { "Pattern" });
  }
}