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

/**** 
* Classes
****/ 
var Coin = Container.expand(function () {
	var self = Container.call(this);
	var coinGraphics = self.attachAsset('coin', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = gameSpeed;
	self.collected = false;
	self.update = function () {
		self.y += self.speed;
		coinGraphics.rotation += 0.1;
	};
	return self;
});
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obstacleGraphics = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.speed = gameSpeed;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var Player = Container.expand(function () {
	var self = Container.call(this);
	var playerGraphics = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.lane = 1; // 0=left, 1=center, 2=right
	self.isJumping = false;
	self.isSliding = false;
	self.jumpStartY = 0;
	self.slideTimer = 0;
	self.update = function () {
		// Handle jumping
		if (self.isJumping) {
			var jumpProgress = (LK.ticks - self.jumpStartTick) / 20;
			if (jumpProgress >= 1) {
				self.isJumping = false;
				self.y = self.jumpStartY;
			} else {
				var jumpHeight = Math.sin(jumpProgress * Math.PI) * 100;
				self.y = self.jumpStartY - jumpHeight;
			}
		}
		// Handle sliding
		if (self.isSliding) {
			self.slideTimer--;
			if (self.slideTimer <= 0) {
				self.isSliding = false;
				playerGraphics.scaleY = 1.0;
			}
		}
		// Update lane position
		var targetX = 512 + self.lane * 512;
		self.x += (targetX - self.x) * 0.2;
	};
	self.jump = function () {
		if (!self.isJumping && !self.isSliding) {
			self.isJumping = true;
			self.jumpStartY = self.y;
			self.jumpStartTick = LK.ticks;
			LK.getSound('jump').play();
		}
	};
	self.slide = function () {
		if (!self.isJumping && !self.isSliding) {
			self.isSliding = true;
			self.slideTimer = 30;
			playerGraphics.scaleY = 0.5;
		}
	};
	self.moveLeft = function () {
		if (self.lane > 0) {
			self.lane--;
		}
	};
	self.moveRight = function () {
		if (self.lane < 2) {
			self.lane++;
		}
	};
	return self;
});
var Track = Container.expand(function () {
	var self = Container.call(this);
	var trackGraphics = self.attachAsset('track', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = gameSpeed;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var Train = Container.expand(function () {
	var self = Container.call(this);
	var trainGraphics = self.attachAsset('train', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.speed = gameSpeed;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});

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

/**** 
* Game Code
****/ 
var gameSpeed = 8;
var difficulty = 'medium';
var obstacleSpawnRate = 120;
var coinSpawnRate = 60;
var distance = 0;
var coins = 0;
var player;
var obstacles = [];
var trains = [];
var coinsList = [];
var tracks = [];
var lastSwipeX = 0;
var lastSwipeY = 0;
var swipeStartX = 0;
var swipeStartY = 0;
var isSwipeStarted = false;
// Initialize tracks for visual effect
for (var i = 0; i < 5; i++) {
	var track = new Track();
	track.x = 1024;
	track.y = i * 200 - 200;
	tracks.push(track);
	game.addChild(track);
}
// Initialize player
player = new Player();
player.x = 1024;
player.y = 2200;
game.addChild(player);
// UI Elements
var scoreText = new Text2('Score: 0', {
	size: 60,
	fill: 0xFFFFFF
});
scoreText.anchor.set(0, 0);
scoreText.x = 120;
scoreText.y = 50;
LK.gui.addChild(scoreText);
var coinsText = new Text2('Coins: 0', {
	size: 60,
	fill: 0xFFD700
});
coinsText.anchor.set(1, 0);
coinsText.x = LK.gui.width - 50;
coinsText.y = 50;
LK.gui.addChild(coinsText);
var distanceText = new Text2('Distance: 0m', {
	size: 50,
	fill: 0xFFFFFF
});
distanceText.anchor.set(0.5, 0);
distanceText.x = LK.gui.width / 2;
distanceText.y = 50;
LK.gui.addChild(distanceText);
// Set difficulty based on game design
function setDifficulty(diff) {
	difficulty = diff;
	switch (diff) {
		case 'easy':
			gameSpeed = 6;
			obstacleSpawnRate = 150;
			coinSpawnRate = 45;
			break;
		case 'medium':
			gameSpeed = 8;
			obstacleSpawnRate = 120;
			coinSpawnRate = 60;
			break;
		case 'hard':
			gameSpeed = 12;
			obstacleSpawnRate = 90;
			coinSpawnRate = 80;
			break;
	}
}
// Set default difficulty
setDifficulty('medium');
// Handle swipe controls
game.down = function (x, y, obj) {
	swipeStartX = x;
	swipeStartY = y;
	isSwipeStarted = true;
};
game.up = function (x, y, obj) {
	if (!isSwipeStarted) return;
	var deltaX = x - swipeStartX;
	var deltaY = y - swipeStartY;
	var swipeThreshold = 50;
	if (Math.abs(deltaX) > Math.abs(deltaY)) {
		// Horizontal swipe
		if (Math.abs(deltaX) > swipeThreshold) {
			if (deltaX > 0) {
				player.moveRight();
			} else {
				player.moveLeft();
			}
		}
	} else {
		// Vertical swipe
		if (Math.abs(deltaY) > swipeThreshold) {
			if (deltaY < 0) {
				player.jump();
			} else {
				player.slide();
			}
		}
	}
	isSwipeStarted = false;
};
// Spawn obstacles
function spawnObstacle() {
	var availableLanes = [0, 1, 2];
	// Remove lanes that already have obstacles or trains in spawn area
	for (var i = obstacles.length - 1; i >= 0; i--) {
		var obstacle = obstacles[i];
		if (obstacle.y >= -300 && obstacle.y <= 100) {
			// Obstacle in spawn area
			var obstacleLaneIndex = availableLanes.indexOf(obstacle.lane);
			if (obstacleLaneIndex > -1) {
				availableLanes.splice(obstacleLaneIndex, 1);
			}
		}
	}
	for (var i = trains.length - 1; i >= 0; i--) {
		var train = trains[i];
		if (train.y >= -400 && train.y <= 100) {
			// Train in spawn area
			var trainLaneIndex = availableLanes.indexOf(train.lane);
			if (trainLaneIndex > -1) {
				availableLanes.splice(trainLaneIndex, 1);
			}
		}
	}
	// If no lanes available, don't spawn obstacle
	if (availableLanes.length === 0) {
		return;
	}
	var lane = availableLanes[Math.floor(Math.random() * availableLanes.length)];
	var obstacleType = Math.random();
	if (obstacleType < 0.6) {
		// Regular obstacle
		var obstacle = new Obstacle();
		obstacle.x = 512 + lane * 512;
		obstacle.y = -100;
		obstacle.lane = lane;
		obstacles.push(obstacle);
		game.addChild(obstacle);
	} else {
		// Train
		var train = new Train();
		train.x = 512 + lane * 512;
		train.y = -150;
		train.lane = lane;
		trains.push(train);
		game.addChild(train);
	}
}
// Spawn coins
function spawnCoin() {
	var availableLanes = [0, 1, 2];
	// Remove lanes that have trains in spawn area
	for (var i = trains.length - 1; i >= 0; i--) {
		var train = trains[i];
		if (train.y >= -600 && train.y <= 200) {
			// Train in spawn area
			var trainLaneIndex = availableLanes.indexOf(train.lane);
			if (trainLaneIndex > -1) {
				availableLanes.splice(trainLaneIndex, 1);
			}
		}
	}
	// If no lanes available, don't spawn coin
	if (availableLanes.length === 0) {
		return;
	}
	var lane = availableLanes[Math.floor(Math.random() * availableLanes.length)];
	var coin = new Coin();
	coin.x = 512 + lane * 512;
	coin.y = -50;
	coin.lane = lane;
	coinsList.push(coin);
	game.addChild(coin);
}
// Check collisions
function checkCollisions() {
	// Check obstacle collisions
	for (var i = obstacles.length - 1; i >= 0; i--) {
		var obstacle = obstacles[i];
		if (obstacle.lane === player.lane && !player.isJumping) {
			if (Math.abs(obstacle.y - player.y) < 80) {
				// Collision detected
				LK.showGameOver();
				return;
			}
		}
	}
	// Check train collisions
	for (var i = trains.length - 1; i >= 0; i--) {
		var train = trains[i];
		if (train.lane === player.lane && !player.isJumping) {
			if (Math.abs(train.y - player.y) < 90) {
				// Collision detected
				LK.showGameOver();
				return;
			}
		}
	}
	// Check coin collection
	for (var i = coinsList.length - 1; i >= 0; i--) {
		var coin = coinsList[i];
		if (!coin.collected && coin.lane === player.lane) {
			if (Math.abs(coin.y - player.y) < 60) {
				coin.collected = true;
				coins++;
				LK.setScore(LK.getScore() + 10);
				LK.getSound('collect').play();
				coin.destroy();
				coinsList.splice(i, 1);
			}
		}
	}
}
// Clean up off-screen objects
function cleanupObjects() {
	// Clean obstacles
	for (var i = obstacles.length - 1; i >= 0; i--) {
		if (obstacles[i].y > 2800) {
			obstacles[i].destroy();
			obstacles.splice(i, 1);
		}
	}
	// Clean trains
	for (var i = trains.length - 1; i >= 0; i--) {
		if (trains[i].y > 2800) {
			trains[i].destroy();
			trains.splice(i, 1);
		}
	}
	// Clean coins
	for (var i = coinsList.length - 1; i >= 0; i--) {
		if (coinsList[i].y > 2800) {
			coinsList[i].destroy();
			coinsList.splice(i, 1);
		}
	}
	// Reset tracks
	for (var i = 0; i < tracks.length; i++) {
		if (tracks[i].y > 2800) {
			tracks[i].y = -200;
		}
	}
}
// Update UI
function updateUI() {
	distance = Math.floor(LK.ticks / 6);
	scoreText.setText('Score: ' + LK.getScore());
	coinsText.setText('Coins: ' + coins);
	distanceText.setText('Distance: ' + distance + 'm');
}
// Main game update
game.update = function () {
	// Update speed over time
	gameSpeed = Math.min(15, 8 + LK.ticks / 1800);
	// Spawn obstacles
	if (LK.ticks % obstacleSpawnRate === 0) {
		spawnObstacle();
	}
	// Spawn coins
	if (LK.ticks % coinSpawnRate === 0) {
		spawnCoin();
	}
	// Update score based on distance
	if (LK.ticks % 6 === 0) {
		LK.setScore(LK.getScore() + 1);
	}
	// Check collisions
	checkCollisions();
	// Clean up objects
	cleanupObjects();
	// Update UI
	updateUI();
};
// Start background music
LK.playMusic('bgmusic');

===================================================================
--- original.js
+++ change.js
@@ -239,9 +239,35 @@
 	isSwipeStarted = false;
 };
 // Spawn obstacles
 function spawnObstacle() {
-	var lane = Math.floor(Math.random() * 3);
+	var availableLanes = [0, 1, 2];
+	// Remove lanes that already have obstacles or trains in spawn area
+	for (var i = obstacles.length - 1; i >= 0; i--) {
+		var obstacle = obstacles[i];
+		if (obstacle.y >= -300 && obstacle.y <= 100) {
+			// Obstacle in spawn area
+			var obstacleLaneIndex = availableLanes.indexOf(obstacle.lane);
+			if (obstacleLaneIndex > -1) {
+				availableLanes.splice(obstacleLaneIndex, 1);
+			}
+		}
+	}
+	for (var i = trains.length - 1; i >= 0; i--) {
+		var train = trains[i];
+		if (train.y >= -400 && train.y <= 100) {
+			// Train in spawn area
+			var trainLaneIndex = availableLanes.indexOf(train.lane);
+			if (trainLaneIndex > -1) {
+				availableLanes.splice(trainLaneIndex, 1);
+			}
+		}
+	}
+	// If no lanes available, don't spawn obstacle
+	if (availableLanes.length === 0) {
+		return;
+	}
+	var lane = availableLanes[Math.floor(Math.random() * availableLanes.length)];
 	var obstacleType = Math.random();
 	if (obstacleType < 0.6) {
 		// Regular obstacle
 		var obstacle = new Obstacle();
@@ -261,9 +287,25 @@
 	}
 }
 // Spawn coins
 function spawnCoin() {
-	var lane = Math.floor(Math.random() * 3);
+	var availableLanes = [0, 1, 2];
+	// Remove lanes that have trains in spawn area
+	for (var i = trains.length - 1; i >= 0; i--) {
+		var train = trains[i];
+		if (train.y >= -600 && train.y <= 200) {
+			// Train in spawn area
+			var trainLaneIndex = availableLanes.indexOf(train.lane);
+			if (trainLaneIndex > -1) {
+				availableLanes.splice(trainLaneIndex, 1);
+			}
+		}
+	}
+	// If no lanes available, don't spawn coin
+	if (availableLanes.length === 0) {
+		return;
+	}
+	var lane = availableLanes[Math.floor(Math.random() * availableLanes.length)];
 	var coin = new Coin();
 	coin.x = 512 + lane * 512;
 	coin.y = -50;
 	coin.lane = lane;