draw the universe

prism.pde

import java.awt.event.*;  

class Path {
  ArrayList points;
  Path() {
    points = new ArrayList();
  }
  
  void add(float x, float y) {
    this.points.add( new PVector( x, y ) );
  }
  
  void draw() {
    beginShape();
    for(int i=0; i<this.points.size(); i++) {
      PVector pt = (PVector)this.points.get(i);
      vertex( pt.x, pt.y );
    }
    endShape();
  }
}

float xtrans=0;
float ytrans=0;
float xscale=1;
float yscale=1;

ArrayList paths = new ArrayList();
Path path = null;

class Person {
 float x;
 float y;
 float width=0.5; //meters 
}

class Button {
  int x;
  int y;
  int width;
  int height;
}

class MouseWheelInput implements MouseWheelListener{

  void mouseWheelMoved(MouseWheelEvent e) {
    int step=e.getWheelRotation();
    xscale = xscale*pow(1.1,step);
    yscale = yscale*pow(1.1,step);
    
    println( xscale );
  }

}

float screenX() {
  return (mouseX-(width/2))/xscale - xtrans;
}

float screenY() {
  return (mouseY-(height/2))/yscale - ytrans;
}

void setup() {
  size(1000,1000);
  background(255);
  smooth();
  strokeWeight(0.5);
  
  frame.addMouseWheelListener(new MouseWheelInput());  
}

void draw() {
  translate(width/2,height/2);
  scale(xscale, yscale);
  pushMatrix();
  translate(xtrans,ytrans);

  background(255);
  noFill();
  
  stroke(255,0,0);
  if( path != null )
    path.draw();
 
  stroke(0);
  for(int i=0; i<paths.size(); i++) {
    ((Path)paths.get(i)).draw();
  }
  
  line(-10,0,10,0);
  line(0,-10,0,10);
  

  popMatrix();

}

void mousePressed() {
  if( mouseButton==37 ) {
    path = new Path();
    path.add( screenX(), screenY() );
  }
}

void mouseReleased() {
  if( mouseButton==37 ){
    paths.add( path );
    path=null;
    
    println( screenX() );
  }
}
  
void mouseDragged() {
  println( mouseButton );
  if( mouseButton==37 ) {
    path.add( screenX(), screenY() );
  } else if( mouseButton==39 ) {
    xtrans += (mouseX-pmouseX)/xscale;
    ytrans += (mouseY-pmouseY)/yscale;
  }
}