/* ***************************
Challenge 3: Motion
Designed By:
Creates a ball that bounces off the edges of the canvas
****************************** */
final int BACKGROUND_COLOR =255;

float ballX;
float ballY;
float ballXVelocity = random(1,10);
float ballYVelocity = random(1,10);
final int BALL_COLOR = 200;
final float BALL_SIZE=80.0;

void setup() {
  size(1280, 800);
  ballX = width/2;
  ballY=height/2;
}

void draw() {
  background(BACKGROUND_COLOR);
  fill(BALL_COLOR);
  ellipse( ballX, ballY, BALL_SIZE, BALL_SIZE);
  //use velocity to simulate motion
  ballX+=ballXVelocity;
  ballY+=ballYVelocity;
  //reverse direction when the ball hits the left/right edges of the canvas
  if (ballX >= width || ballX <= 0){
    ballXVelocity *= -1;
  }
  //reverse direction when the ball hits the top/bottom edges of the canvas
  if (ballY >= height || ballY <= 0){
    ballYVelocity *= -1;
  }
}