Code Sketch

// Clear the canvas and prepare the game stage
clear()
drawStage(ColorMaker.black)

// Retrieve the dimensions of the active canvas
val cb = canvasBounds

// ------------------------------------------------------------
// GAME STATE & VARIABLES
// ------------------------------------------------------------
var score = 0
var gameRunning = true

// FIX: Used Picture.text instead of StPicture
val scoreText = Picture.text(s"Score: $score", 20)
scoreText.setFillColor(white)
scoreText.setPosition(cb.x + 20, cb.y + cb.height - 40)
draw(scoreText)

// FIX: Used Picture.text instead of StPicture
val gameOverText = Picture.text("GAME OVER! Press R to Restart", 24)
gameOverText.setFillColor(red)
gameOverText.setHeading(0)
gameOverText.setPosition(cb.x + (cb.width / 2) - 180, cb.y + (cb.height / 2))

// ------------------------------------------------------------
// GAME OBJECTS (Paddle and Ball)
// ------------------------------------------------------------
// Player Paddle: A green rectangle controlled by arrow keys
val paddle = Picture.rectangle(100, 20)
paddle.setFillColor(green)
paddle.setPosition(cb.x + (cb.width / 2) - 50, cb.y + 40)
draw(paddle)

// Falling Ball: A red circle falling from the top
val ball = Picture.circle(15)
ball.setFillColor(red)

// Function to reset the ball position randomly at the top of the screen
def resetBall(): Unit = {
    val randomX = cb.x + randomDouble(15, cb.width - 30)
    ball.setPosition(randomX, cb.y + cb.height - 40)
}
resetBall()
draw(ball)

// ------------------------------------------------------------
// KEYBOARD CONTROLS & INTERACTION
// ------------------------------------------------------------
// Listen for player movements and restart command
onKeyPress { k =>
    if (gameRunning) {
        // FIX: Changed to Kc.VK_LEFT
        if (k == Kc.VK_LEFT && paddle.position.x > cb.x) {
            paddle.translate(-20, 0)
        }
        // FIX: Changed to Kc.VK_RIGHT
        if (k == Kc.VK_RIGHT && paddle.position.x + 100 < cb.x + cb.width) {
            paddle.translate(20, 0)
        }
    } else {
        // FIX: Changed to Kc.VK_R
        if (k == Kc.VK_R) {
            score = 0
            scoreText.update(s"Score: $score")
            gameOverText.erase()
            resetBall()
            gameRunning = true
        }
    }
}

// ------------------------------------------------------------
// MAIN GAME LOOP (Animation)
// ------------------------------------------------------------
animate {
    if (gameRunning) {
        // Make the ball fall downwards. Speed increases slightly as score goes up.
        val fallSpeed = -4.0 - (score * 0.5)
        ball.translate(0, fallSpeed)
        
        // COLLISION CHECK: Did the ball hit the paddle?
        if (ball.collidesWith(paddle)) {
            score += 1
            scoreText.update(s"Score: $score")
            resetBall()
        }
        
        // LOSE CONDITION: Did the ball fall past the bottom edge?
        if (ball.position.y < cb.y) {
            gameRunning = false
            draw(gameOverText)
        }
    }
}