pong

float xPos;

float yPos;

float xSpeed;

float ySpeed;

float startSpeed = 2;

​

void setup () {

  size(500,400);

  background(150);

  //defines innitial position of ellipse

  xPos = width/2;

  yPos = height/2;

  strokeWeight(5);

  //defines the inital speed of the ellipse

  xSpeed = startSpeed;

  ySpeed = startSpeed;

}

​

​

void draw () {

  //adds faded background

  //creates ghosting effect

  noStroke();

  fill(150,150,150,100);

  rect(0,0,width,height);

  //checks if ellipse is within width and height

  //reverses speed direction on collision

  if (xPos > (width-26) || xPos < 26) {xSpeed*=-1;}

  if (yPos > (height-26) || yPos < 26) {ySpeed*=-1;}

  //applies speed to ellipse

  xPos+=xSpeed;

  yPos+=ySpeed;

  //draws ellipse 

  noFill();

  stroke(255);

  ellipse(xPos,yPos,50,50);

}

​

​