all four

float posX=10;

float posY=0;

float speedX = 1;

float speedY = 6;

int backgroundColor = 255;

​

​

void setup() {

  size(300, 300);

}

​

void draw() {

  background(backgroundColor);

  posX = posX + speedX;

  posY = posY + speedY;

​

​

​

  // draw a circle at x,y with diam of 20

  rect(posX, posY, 20, 20 );

  fill(random(0, 100), random(0, 200), random(0, 75));

  // move circle to right, or changing it's x coord in pos dir every time

  if(posX <= 0){

    speedX = speedX * -1;

    println( "less than is TRUE!" );

  }

  //if circle hits right frame wall, return

  if(posX >= width){

   speedX = speedX * -1;

   println( "greater than is TRUE!" );

  }

  //if circle hits max width, move up (increase Y)

  if(posY >= height){

    speedY= speedY* -1;

    backgroundColor = 230;

    println( "greater than is TRUE!" );

  }

    if(posY <= 0){

      backgroundColor = 100;

    speedY = speedY * -1;

    println( "less than is TRUE!" );

  }

}