script.js

const gameArea = document.getElementById('gameArea');
const paddleLeft = document.getElementById('paddleLeft');
const paddleRight = document.getElementById('paddleRight');
const ball = document.getElementById('ball');
const playerScoreDisplay = document.getElementById('playerScore');
const botScoreDisplay = document.getElementById('botScore');

let paddleLeftY = window.innerHeight / 2 - 40;
let paddleRightY = window.innerHeight / 2 - 40;
let ballX = window.innerWidth / 2;
let ballY = window.innerHeight / 2;
let ballSpeedX = 3;
let ballSpeedY = 0;
let playerScore = 0;
let botScore = 0;
let isGamePaused = true;

const paddleHeight = 80;
const paddleWidth = 10;
const ballSize = 15;
const maxAngle = 45;

gameArea.addEventListener('touchmove', (e) => {
    e.preventDefault();
    let touchY = e.touches[0].clientY;

    if (e.touches[0].clientX < window.innerWidth / 2) {
        paddleLeftY = touchY - paddleHeight / 2;
        paddleLeftY = Math.max(0, Math.min(paddleLeftY, window.innerHeight - paddleHeight));

        if (isGamePaused) {
            isGamePaused = false;
        }
    }
});

function handlePaddleCollision(paddleY, paddleX, isLeftPaddle) {
    let previousBallX = ballX - ballSpeedX;
    
    // Swept collision detection: Check if the ball crossed the paddle between frames
    if (
        previousBallX < paddleX + paddleWidth &&
        ballX > paddleX &&
        ballY + ballSize > paddleY &&
        ballY < paddleY + paddleHeight
    ) {
        const hitPosition = (ballY - (paddleY + paddleHeight / 2)) / (paddleHeight / 2);
        const angle = hitPosition * maxAngle * (Math.PI / 180);

        ballSpeedX = (isLeftPaddle ? 1 : -1) * Math.abs(ballSpeedX);
        ballSpeedY = Math.sin(angle) * Math.abs(ballSpeedX);

        // Reposition the ball outside the paddle to avoid clipping
        ballX = isLeftPaddle ? paddleX + paddleWidth + 1 : paddleX - ballSize - 1;
    }
}

function update() {
    if (!isGamePaused) {
        let previousBallX = ballX;
        ballX += ballSpeedX;
        ballY += ballSpeedY;

        // Ball collision with top and bottom walls
        if (ballY <= 0 || ballY >= window.innerHeight - ballSize) {
            ballSpeedY = -ballSpeedY;
        }

        // Check collision with left paddle using swept collision detection
        handlePaddleCollision(paddleLeftY, paddleWidth, true);

        // Check collision with right paddle using swept collision detection
        handlePaddleCollision(paddleRightY, window.innerWidth - paddleWidth - 25, false);

        // Ball out of bounds
        if (ballX <= 0) {
            botScore++;
            botScoreDisplay.textContent = botScore;
            resetBall('right');
        } else if (ballX >= window.innerWidth) {
            playerScore++;
            playerScoreDisplay.textContent = playerScore;
            resetBall('left');
        }
    }

    // Bot AI movement
    if (ballSpeedX > 0) {
        if (paddleRightY + paddleHeight / 2 < ballY) {
            paddleRightY += 3;
        } else if (paddleRightY + paddleHeight / 2 > ballY) {
            paddleRightY -= 3;
        }
    }

    paddleRightY = Math.max(0, Math.min(paddleRightY, window.innerHeight - paddleHeight));

    ball.style.left = ballX + 'px';
    ball.style.top = ballY + 'px';
    paddleLeft.style.top = paddleLeftY + 'px';
    paddleRight.style.top = paddleRightY + 'px';

    requestAnimationFrame(update);
}

function resetBall(side) {
    isGamePaused = true;

    if (side === 'left') {
        ballX = paddleWidth + 10;
        ballY = paddleLeftY + paddleHeight / 2;
        ballSpeedX = Math.abs(ballSpeedX);
    } else {
        ballX = window.innerWidth - paddleWidth - 25;
        ballY = paddleRightY + paddleHeight / 2;
        ballSpeedX = -Math.abs(ballSpeedX);
    }

    ballSpeedY = 0;
}

// Start the game loop
update();