// COMP1405/1005 - Day 07
//   circle moves horizontally on 
//   the screen, bouncing back and forth
// mjh-2013

// declare variables to be used in the 
// program
int x,y;     // coordinate of circle
int stepx;   // step size of each movement 

// Initialize program
void setup(){
  size(600,400);
  background(222,222,0);
  fill(0);
  x = 0;              // starting point 
  y = height/2;       // for circle
  textSize(40);
  stepx = 4;          // initial step size
}


// main body of program
void draw(){
  // check if the circle has hit a wall
  // turn around if it did
  if (x > width){
    stepx = -1 * stepx;
  }else if( x<0 ){
    stepx = -1 * stepx;
  }   
 
  // draw the ball (and mouse location)
  background(222,222,0);
  text( "(" + x + "," + y + ")", 30,30);
  ellipse(x,y,20,20);
  
  // compute new x position (take a step)
  x = x + stepx ; 
}