/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
var Background = Container.expand(function () {
	var self = Container.call(this);
	// Create sky
	var sky = self.attachAsset('sky', {
		anchorX: 0,
		anchorY: 0
	});
	// Create scrolling ground
	var ground1 = self.attachAsset('ground', {
		anchorX: 0,
		anchorY: 0
	});
	var ground2 = self.attachAsset('ground', {
		anchorX: 0,
		anchorY: 0
	});
	// Position ground at bottom of screen
	ground1.y = 2732 - ground1.height;
	ground2.y = 2732 - ground2.height;
	ground2.x = ground1.width;
	self.ground1 = ground1;
	self.ground2 = ground2;
	self.groundY = ground1.y;
	// Update ground scroll effect
	self.update = function () {
		if (game.gameActive) {
			// Scroll ground
			ground1.x -= 5;
			ground2.x -= 5;
			// Loop ground tiles
			if (ground1.x <= -ground1.width) {
				ground1.x = ground2.x + ground2.width;
			}
			if (ground2.x <= -ground2.width) {
				ground2.x = ground1.x + ground1.width;
			}
		}
	};
	return self;
});
var Bird = Container.expand(function () {
	var self = Container.call(this);
	// Bird graphics
	var birdGraphics = self.attachAsset('bird', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Bird physics
	self.velocity = 0;
	self.gravity = 0.5;
	self.flapPower = -10;
	self.rotation = 0;
	self.isDead = false;
	self.lastY = 0;
	// Flap the bird's wings (jump)
	self.flap = function () {
		if (self.isDead) return;
		self.velocity = self.flapPower;
		LK.getSound('flap').play();
		// Animate rotation upward
		tween(self, {
			rotation: -0.3
		}, {
			duration: 100,
			easing: tween.easeOut
		});
	};
	// Update bird position and physics
	self.update = function () {
		self.lastY = self.y;
		if (!self.isDead) {
			// Apply gravity
			self.velocity += self.gravity;
			self.y += self.velocity;
			// Rotate bird based on velocity
			if (self.velocity > 0) {
				var targetRotation = Math.min(Math.PI / 2, self.velocity * 0.05);
				tween(self, {
					rotation: targetRotation
				}, {
					duration: 200,
					easing: tween.linear
				});
			}
		}
	};
	// Handle bird death
	self.die = function () {
		if (self.isDead) return;
		self.isDead = true;
		LK.getSound('hit').play();
		// Animate death (fall with rotation)
		tween(self, {
			rotation: Math.PI / 2
		}, {
			duration: 500,
			easing: tween.easeIn
		});
	};
	return self;
});
var Pipe = Container.expand(function () {
	var self = Container.call(this);
	// Pipe properties
	self.speed = 5;
	self.passed = false;
	self.lastX = 0;
	// Create top and bottom pipes
	self.init = function (gapY, gapHeight) {
		// Top pipe
		var topPipe = self.attachAsset('pipe', {
			anchorX: 0.5,
			anchorY: 1.0 // Bottom anchor
		});
		topPipe.y = gapY - gapHeight / 2;
		// Bottom pipe
		var bottomPipe = self.attachAsset('pipe', {
			anchorX: 0.5,
			anchorY: 0.0 // Top anchor
		});
		bottomPipe.y = gapY + gapHeight / 2;
		// Store references
		self.topPipe = topPipe;
		self.bottomPipe = bottomPipe;
	};
	// Update pipe position
	self.update = function () {
		self.lastX = self.x;
		self.x -= self.speed;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000000
});

/**** 
* Game Code
****/ 
// Set background color
game.setBackgroundColor(0x87CEEB);
// Game variables
var pipes = [];
var pipeSpawnInterval = 90; // In ticks (frames)
var gapHeight = 300; // Gap between pipes
var score = 0;
var gameStarted = false;
var gameActive = true;
game.gameActive = gameActive; // Make it accessible to other classes
// Create background
var background = new Background();
game.addChild(background);
// Create bird
var bird = new Bird();
bird.x = 400;
bird.y = 2732 / 2;
game.addChild(bird);
// Create score text
var scoreText = new Text2('0', {
	size: 150,
	fill: 0xFFFFFF
});
scoreText.anchor.set(0.5, 0);
scoreText.y = 100;
scoreText.x = 2048 / 2;
LK.gui.top.addChild(scoreText);
// Create tap to start text
var startText = new Text2('TAP TO START', {
	size: 100,
	fill: 0xFFFFFF
});
startText.anchor.set(0.5, 0.5);
startText.x = 2048 / 2;
startText.y = 2732 / 2;
LK.gui.center.addChild(startText);
// Create flash overlay for game over
var flashOverlay = LK.getAsset('flash', {
	anchorX: 0,
	anchorY: 0,
	alpha: 0
});
game.addChild(flashOverlay);
// Game event handlers
game.down = function (x, y, obj) {
	if (!gameStarted) {
		// First tap starts the game
		gameStarted = true;
		startText.visible = false;
	}
	if (gameActive) {
		bird.flap();
	}
};
// Spawn a new pipe pair
function spawnPipe() {
	var pipe = new Pipe();
	// Random gap position between pipes (constrained to middle 60% of screen)
	var minY = 2732 * 0.2;
	var maxY = 2732 * 0.8 - background.ground1.height;
	var gapY = minY + Math.random() * (maxY - minY);
	pipe.init(gapY, gapHeight);
	pipe.x = 2048 + 100;
	pipes.push(pipe);
	game.addChild(pipe);
}
// Check collisions
function checkCollisions() {
	// Ground collision
	if (bird.y + bird.height / 2 >= background.groundY) {
		bird.y = background.groundY - bird.height / 2;
		gameOver();
		return;
	}
	// Ceiling collision
	if (bird.y - bird.height / 2 <= 0) {
		bird.y = bird.height / 2;
		bird.velocity = 0;
	}
	// Pipe collisions
	for (var i = 0; i < pipes.length; i++) {
		var pipe = pipes[i];
		if (bird.intersects(pipe.topPipe) || bird.intersects(pipe.bottomPipe)) {
			gameOver();
			return;
		}
		// Score when passing pipe
		if (!pipe.passed && pipe.lastX > bird.x && pipe.x <= bird.x) {
			pipe.passed = true;
			score++;
			LK.setScore(score);
			scoreText.setText(score.toString());
			LK.getSound('score').play();
		}
	}
}
// Game over handling
function gameOver() {
	if (!gameActive) return;
	gameActive = false;
	game.gameActive = false;
	bird.die();
	// Flash effect
	flashOverlay.alpha = 0.8;
	tween(flashOverlay, {
		alpha: 0
	}, {
		duration: 500,
		easing: tween.easeOut,
		onFinish: function onFinish() {
			// Show game over after flash
			LK.setTimeout(function () {
				LK.showGameOver();
			}, 1000);
		}
	});
}
// Main game update loop
game.update = function () {
	if (!gameStarted) return;
	// Update bird
	bird.update();
	if (gameActive) {
		// Spawn pipes at interval
		if (LK.ticks % pipeSpawnInterval === 0) {
			spawnPipe();
		}
		// Update pipes
		for (var i = pipes.length - 1; i >= 0; i--) {
			var pipe = pipes[i];
			pipe.update();
			// Remove pipes that have gone off screen
			if (pipe.x < -150) {
				pipe.destroy();
				pipes.splice(i, 1);
			}
		}
		// Check for collisions
		checkCollisions();
	}
	// Update background
	background.update();
};

===================================================================
--- original.js
+++ change.js
@@ -45,9 +45,8 @@
 		}
 	};
 	return self;
 });
-// Set background color
 var Bird = Container.expand(function () {
 	var self = Container.call(this);
 	// Bird graphics
 	var birdGraphics = self.attachAsset('bird', {
@@ -150,18 +149,8 @@
 /**** 
 * Game Code
 ****/ 
 // Set background color
-/* 
-* Assets
-*/
-// Bird character
-// Pipe obstacle (top and bottom)
-// Background ground
-// Sky background
-// Game over flash effect
-// Sound effects
-// Import tween plugin for animations
 game.setBackgroundColor(0x87CEEB);
 // Game variables
 var pipes = [];
 var pipeSpawnInterval = 90; // In ticks (frames)