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

/**** 
* Classes
****/ 
// Coin
var Coin = Container.expand(function () {
	var self = Container.call(this);
	var coinGfx = self.attachAsset('coin', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Lane: 0,1,2
	self.lane = 1;
	// For collision detection
	self.isCoin = true;
	return self;
});
// Obstacle
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obsGfx = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Lane: 0,1,2
	self.lane = 1;
	// For collision detection
	self.isObstacle = true;
	return self;
});
// Runner (player character)
var Runner = Container.expand(function () {
	var self = Container.call(this);
	var runnerGfx = self.attachAsset('runner', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Current lane: 0 (left), 1 (center), 2 (right)
	self.lane = 1;
	// Move to lane (0,1,2)
	self.moveToLane = function (lane, duration) {
		self.lane = lane;
		var targetX = laneToX(lane);
		tween(self, {
			x: targetX
		}, {
			duration: duration || 120,
			easing: tween.cubicOut
		});
	};
	return self;
});

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

/**** 
* Game Code
****/ 
// Coin: Yellow ellipse
// Obstacle: Gray box
// Character: Red box
// --- ROAD BACKGROUND ---
var roadBg1 = LK.getAsset('road', {
	anchorX: 0.5,
	anchorY: 0
});
roadBg1.x = 2048 / 2;
roadBg1.y = 0;
game.addChild(roadBg1);
var roadBg2 = LK.getAsset('road', {
	anchorX: 0.5,
	anchorY: 0
});
roadBg2.x = 2048 / 2;
roadBg2.y = -2732;
game.addChild(roadBg2);
// --- LANE SYSTEM ---
var NUM_LANES = 3;
var LANE_WIDTH = 2048 / NUM_LANES; // Use full width
var LANE_START_X = LANE_WIDTH / 2; // Center of first lane at left edge
function laneToX(lane) {
	// lane: 0 (left), 1 (center), 2 (right)
	return LANE_START_X + lane * LANE_WIDTH;
}
// --- GAMEPLAY VARIABLES ---
var runner;
var obstacles = [];
var coins = [];
var speed = 18; // Initial speed (pixels per frame)
var speedIncrease = 0.012; // Speed up per tick
var spawnTimer = 0;
var coinSpawnTimer = 0;
var minObstacleGap = 420; // Minimum vertical gap between obstacles
var lastObstacleY = 0;
var isGameOver = false;
// --- SCORE ---
var score = 0;
var scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// --- INIT RUNNER ---
runner = new Runner();
runner.y = 2732 - 400;
runner.x = laneToX(1);
runner.lane = 1;
game.addChild(runner);
// --- INPUT HANDLING ---
var dragStartX = null;
var dragStartLane = null;
var dragActive = false;
function handleMove(x, y, obj) {
	if (dragActive && dragStartX !== null) {
		var dx = x - dragStartX;
		if (Math.abs(dx) > 120) {
			// Swipe detected
			if (dx > 0 && runner.lane < NUM_LANES - 1) {
				runner.moveToLane(runner.lane + 1);
				dragStartX = x;
			} else if (dx < 0 && runner.lane > 0) {
				runner.moveToLane(runner.lane - 1);
				dragStartX = x;
			}
		}
	}
}
game.move = handleMove;
game.down = function (x, y, obj) {
	dragActive = true;
	dragStartX = x;
	dragStartLane = runner.lane;
};
game.up = function (x, y, obj) {
	dragActive = false;
	dragStartX = null;
	dragStartLane = null;
};
// --- TAP TO MOVE (for single taps) ---
game.tap = function (x, y, obj) {
	// Not supported by LK, so handled via down/up quick tap
	// (No implementation needed)
};
// --- SPAWN OBSTACLES & COINS ---
function spawnObstacle() {
	var lane = Math.floor(Math.random() * NUM_LANES);
	var obs = new Obstacle();
	obs.lane = lane;
	obs.x = laneToX(lane);
	obs.y = -180;
	obstacles.push(obs);
	game.addChild(obs);
	lastObstacleY = obs.y;
}
function spawnCoin() {
	// Prevent coins from spawning in the same lane and too close to obstacles, and at the same Y as obstacles
	var availableLanes = [0, 1, 2];
	var coinSpawnY = -120;
	// Remove lanes with obstacles too close to spawn Y or at the same Y
	for (var i = 0; i < obstacles.length; i++) {
		var obs = obstacles[i];
		// If obstacle is in the same lane and within 320px vertically of coin spawn Y (-120)
		if (Math.abs(obs.y - coinSpawnY) < 320) {
			var idx = availableLanes.indexOf(obs.lane);
			if (idx !== -1) availableLanes.splice(idx, 1);
		}
		// Prevent coin from spawning at the same Y as any obstacle (even in other lanes)
		if (Math.abs(obs.y - coinSpawnY) < 1) {
			// If any obstacle is at the same Y, skip coin spawn entirely
			return;
		}
	}
	if (availableLanes.length === 0) return; // No safe lane, skip coin spawn
	var lane = availableLanes[Math.floor(Math.random() * availableLanes.length)];
	var coin = new Coin();
	coin.lane = lane;
	coin.x = laneToX(lane);
	coin.y = coinSpawnY;
	coins.push(coin);
	game.addChild(coin);
}
// --- COLLISION DETECTION ---
function checkCollision(a, b) {
	// Simple AABB
	var dx = Math.abs(a.x - b.x);
	var dy = Math.abs(a.y - b.y);
	var aw = a.width || 180,
		ah = a.height || 180;
	var bw = b.width || 180,
		bh = b.height || 180;
	return dx < aw / 2 + bw / 2 - 20 && dy < ah / 2 + bh / 2 - 20;
}
// --- GAME LOOP ---
game.update = function () {
	if (isGameOver) return;
	// Scroll road background
	roadBg1.y += speed;
	roadBg2.y += speed;
	// Loop backgrounds
	if (roadBg1.y >= 2732) {
		roadBg1.y = roadBg2.y - 2732;
	}
	if (roadBg2.y >= 2732) {
		roadBg2.y = roadBg1.y - 2732;
	}
	// Increase speed
	speed += speedIncrease;
	// Move obstacles
	for (var i = obstacles.length - 1; i >= 0; i--) {
		var obs = obstacles[i];
		obs.y += speed;
		if (obs.y > 2732 + 200) {
			obs.destroy();
			obstacles.splice(i, 1);
			continue;
		}
		// Collision with runner
		if (checkCollision(obs, runner)) {
			isGameOver = true;
			LK.effects.flashScreen(0xff0000, 800);
			LK.showGameOver();
			return;
		}
	}
	// Move coins
	for (var j = coins.length - 1; j >= 0; j--) {
		var coin = coins[j];
		coin.y += speed;
		if (coin.y > 2732 + 120) {
			coin.destroy();
			coins.splice(j, 1);
			continue;
		}
		// Collision with runner
		if (checkCollision(coin, runner)) {
			// Collect coin
			score += 1;
			LK.setScore(score);
			scoreTxt.setText(score);
			LK.effects.flashObject(coin, 0xffff00, 200);
			coin.destroy();
			coins.splice(j, 1);
			continue;
		}
	}
	// Spawn obstacles
	spawnTimer -= speed;
	if (spawnTimer <= 0) {
		spawnObstacle();
		// Next spawn in 700-1100 px
		spawnTimer = minObstacleGap + Math.floor(Math.random() * 400);
	}
	// Spawn coins
	coinSpawnTimer -= speed;
	if (coinSpawnTimer <= 0) {
		spawnCoin();
		// Next coin in 400-900 px
		coinSpawnTimer = 400 + Math.floor(Math.random() * 500);
	}
};
// --- RESET ON GAME OVER ---
game.on('destroy', function () {
	// Clean up arrays
	for (var i = 0; i < obstacles.length; i++) {
		obstacles[i].destroy();
	}
	for (var j = 0; j < coins.length; j++) {
		coins[j].destroy();
	}
	obstacles = [];
	coins = [];
	isGameOver = false;
	speed = 18;
	score = 0;
	LK.setScore(0);
	scoreTxt.setText('0');
	runner.x = laneToX(1);
	runner.lane = 1;
	runner.y = 2732 - 400;
	spawnTimer = 0;
	coinSpawnTimer = 0;
	roadBg1.y = 0;
	roadBg2.y = -2732;
});

===================================================================
--- original.js
+++ change.js
@@ -67,8 +67,23 @@
 ****/ 
 // Coin: Yellow ellipse
 // Obstacle: Gray box
 // Character: Red box
+// --- ROAD BACKGROUND ---
+var roadBg1 = LK.getAsset('road', {
+	anchorX: 0.5,
+	anchorY: 0
+});
+roadBg1.x = 2048 / 2;
+roadBg1.y = 0;
+game.addChild(roadBg1);
+var roadBg2 = LK.getAsset('road', {
+	anchorX: 0.5,
+	anchorY: 0
+});
+roadBg2.x = 2048 / 2;
+roadBg2.y = -2732;
+game.addChild(roadBg2);
 // --- LANE SYSTEM ---
 var NUM_LANES = 3;
 var LANE_WIDTH = 2048 / NUM_LANES; // Use full width
 var LANE_START_X = LANE_WIDTH / 2; // Center of first lane at left edge
@@ -187,8 +202,18 @@
 }
 // --- GAME LOOP ---
 game.update = function () {
 	if (isGameOver) return;
+	// Scroll road background
+	roadBg1.y += speed;
+	roadBg2.y += speed;
+	// Loop backgrounds
+	if (roadBg1.y >= 2732) {
+		roadBg1.y = roadBg2.y - 2732;
+	}
+	if (roadBg2.y >= 2732) {
+		roadBg2.y = roadBg1.y - 2732;
+	}
 	// Increase speed
 	speed += speedIncrease;
 	// Move obstacles
 	for (var i = obstacles.length - 1; i >= 0; i--) {
@@ -263,5 +288,7 @@
 	runner.lane = 1;
 	runner.y = 2732 - 400;
 	spawnTimer = 0;
 	coinSpawnTimer = 0;
+	roadBg1.y = 0;
+	roadBg2.y = -2732;
 });
\ No newline at end of file