void display()
{
  if(displayMode==1)
    rawr.drawLattice();  
  if(displayMode==2)
    rawr.drawCells();  
  if(displayMode==3)
    rawr.drawLines();      
}

void ellipse(position p,float d)
{
  ellipse(p.x,p.y,d,d);
}

void drawArrow(position p1,position p2)
{
  position corner=new position(new position(0,0));
  position bLeft=new position(corner.displace(140,4));
  position bRight=new position(corner.displace(220,4));
  float heading=radians(360-getHeading(p1,p2));  
  push();
  line(p1.x,p1.y,p2.x,p2.y);
  translate(p2.x,p2.y);
  rotate(heading);
  beginShape(POLYGON);
  vertex(corner.x,corner.y);
  vertex(bLeft.x,bLeft.y);
  vertex(bRight.x,bRight.y);
  endShape();
  pop();
}