//Programming Digital Media
//PONG Project- Final Version Example
//code by Matthew A. Bardin [2019]


//declaring and initializing variables
let ballX, ballY, leftScore, rightScore;
let ballAngle = 0;
let ballSpeed = 0;
//this one is an array to choose ball angle when bounced
let ballAngleChoice = [-2, -1, 0, 1, 2];
let rPaddleY = 0;


function setup() {
  createCanvas(windowWidth, windowHeight);
  //slows down the ball and paddle movement to look more like the old games. Optional.
  frameRate(30);
  //sets starting ball position and scores
  ballX = random(50, width - 50);
  ballY = random(50, (height - 50));
  leftScore = 0;
  rightScore = 0;
}

function draw() {
  background('black');
  fill('white'); //will need stroke("white"); if a line is used for the divider in stead of a rectangle
  //divider. made with a rectangle
  rect(width / 2, 0, 2, height);
  //right paddle - follows the arrow keys vertically
  rect(width - 10, rPaddleY, 10, 50);
  //left paddle- follows the mouse vertically
  rect(0, mouseY, 10, 50);
  //ball
  rect(ballX, ballY, 10, 10);

  //score counters
  textFont("Courier New");
  textSize(45);
  textAlign(CENTER);
  text(leftScore, width * 0.25, 50);
  text(rightScore, width * 0.75, 50);

  //instructions
  textSize(12);
  text("The mouse controls the left paddle. The Up and Down Arrows control the right paddle. ", width / 2, height - 50);
  text("Press ESC  to Start!!", width / 2, height - 25);

  //makes the ball move horizontally and vertically. This is the muscle of the project.
  ballX = ballX + ballSpeed;
  ballY = ballY + ballAngle;

  //if statement to control the right paddle
  if (keyIsPressed && keyCode == UP_ARROW) {
    rPaddleY = rPaddleY - 10;
  } else if (keyIsPressed && keyCode == DOWN_ARROW) {
    rPaddleY = rPaddleY + 10;
  } else if (keyIsPressed && keyCode == 27) { //starts the game if ESC is pressed. Also adjusts the ball angle.
    ballSpeed = -4;
    ballAngle = random(ballAngleChoice);
  }
  //keeps right paddle on the screen
  if (rPaddleY < 0) {
    rPaddleY = 0;
  } else if (rPaddleY > (height - 50)) {
    rPaddleY = height - 50;
  }

  //makes the ball bounce off left paddle. This is the brain of the project
  if (ballX < 10) {
    if (ballY > mouseY && ballY < (mouseY + 50)) {
      ballSpeed = 4;
      ballAngle = random(ballAngleChoice);
    }
  }
  //makes the ball bounce off right paddle. This is the brain of the project.
  if (ballX > width - 20) { //needs to be the width of the paddle and the ball
    if (ballY > rPaddleY && ballY < (rPaddleY + 50)) {
      ballSpeed = -4;
      ballAngle = random(ballAngleChoice);
    }
  }

  //resets ball when it moves off of the screen vertically
  if (ballY < 2 || ballY > height - 2) {
    ballY = random(50, (height - 50));
  }

  //update scores and resets ball when ball passes horizontal edges of the screen. flips ball direction as well.
  if (ballX < -75) {
    rightScore++;
    ballX = width / 2;
    ballSpeed = 4
  } else if (ballX > width + 75) {
    leftScore++;
    ballX = width / 2;
    ballSpeed = -4
  }
}