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

/**** 
* Classes
****/ 
// Car class
var Car = Container.expand(function () {
	var self = Container.call(this);
	var carAsset = self.attachAsset('car', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Direction: 1 = up-right (45deg), -1 = up-left (135deg)
	self.direction = 1;
	self.speed = 16; // initial speed in px per tick
	self.angleRight = Math.PI / 4; // 45deg (up-right)
	self.angleLeft = 3 * Math.PI / 4; // 135deg (up-left)
	carAsset.rotation = self.angleRight;
	// Only allow up-left and up-right, always moving up at an angle
	self.setDirection = function (dir) {
		// Only allow -1 (up-left) or 1 (up-right)
		if (dir !== 1 && dir !== -1) return;
		self.direction = dir;
		// Animate rotation
		tween(carAsset, {
			rotation: dir === 1 ? self.angleRight : self.angleLeft
		}, {
			duration: 120,
			easing: tween.cubicOut
		});
	};
	// Move car visually left/right (simulate up-left/up-right)
	self.moveForward = function () {
		// Car moves left/right along the gray road line based on direction
		// Road line is centered at 2048/2, width 960
		var roadLineCenter = 2048 / 2;
		var roadLineWidth = 960;
		var carTravelEdge = roadLineWidth / 2 - self.width / 2 - 30; // 30px margin
		// -1 = left, 1 = right
		var targetX = roadLineCenter + self.direction * carTravelEdge;
		// Smoothly move car toward targetX
		var moveSpeed = 0.22; // 0..1, how fast to interpolate
		self.x += (targetX - self.x) * moveSpeed;
	};
	// Reset to center bottom
	self.resetPosition = function () {
		self.x = 2048 / 2;
		self.y = 2732 - 350;
		self.setDirection(1);
	};
	return self;
});
// White dotted line class
var DottedLine = Container.expand(function () {
	var self = Container.call(this);
	// Each dotted line is a white rectangle (box)
	var dotWidth = 32;
	var dotHeight = 120;
	var dotAsset = self.attachAsset('dottedLine', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Set size and color
	dotAsset.width = dotWidth;
	dotAsset.height = dotHeight;
	dotAsset.color = 0xffffff;
	// Center on road
	self.x = 2048 / 2;
	// y is set on spawn
	self.update = function () {
		// Move down at car speed
		self.y += car.speed;
		// Remove if offscreen (handled in game.update)
	};
	return self;
});
// Obstacle class
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obsAsset = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// side: -1 = left, 1 = right
	self.side = 1;
	self.passed = false;
	// Set position based on side
	self.setSide = function (side) {
		self.side = side;
		// Road is centered at 2048/2, width 600
		var roadCenter = 2048 / 2;
		var roadWidth = 600;
		var margin = 80;
		var xOffset = (roadWidth / 2 - obsAsset.width / 2 - margin) * side;
		self.x = roadCenter + xOffset;
	};
	// Set y position
	self.setY = function (y) {
		self.y = y;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x222222
});

/**** 
* Game Code
****/ 
// Road
// Car: red box, 180x120
// Obstacle: yellow ellipse, 160x100
// Road: dark gray box, 600x2732 (full height)
var road = LK.getAsset('road', {
	anchorX: 0.5,
	anchorY: 0,
	x: 2048 / 2,
	y: 0
});
game.addChild(road);
// Add a vertical gray line in the center of the road
var roadLine;
var roadLineAsset = LK.getAsset('roadLine', {
	anchorX: 0.5,
	anchorY: 0,
	x: 2048 / 2,
	y: 0
});
game.addChild(roadLineAsset);
// Car
// (Drifting line removed)
var car = new Car();
game.addChild(car);
car.resetPosition();
// Obstacles array
var obstacles = [];
// Score
var scoreTxt = new Text2('0', {
	size: 120,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Dotted lines (white, moving down the center of the road)
var dottedLines = [];
var dottedLineHeight = 120;
var dottedLineSpacing = 320;
var numDottedLines = Math.ceil(2732 / dottedLineSpacing) + 2; // enough to cover screen + buffer
for (var i = 0; i < numDottedLines; ++i) {
	var dot = new DottedLine();
	// Always spawn at the top middle, spaced downwards
	dot.x = 2048 / 2;
	dot.y = -dottedLineHeight / 2 + i * dottedLineSpacing;
	dottedLines.push(dot);
	game.addChild(dot);
}
// Game state
var gameOver = false;
var passedObstacles = 0;
var ticksSinceLastObstacle = 0;
var obstacleInterval = 90; // ticks between obstacles (start)
var minObstacleInterval = 36; // minimum interval (faster)
var speedIncreaseEvery = 10; // every 10 obstacles, speed up
var carBaseSpeed = 16;
var carMaxSpeed = 36;
// Helper: spawn obstacle
function spawnObstacle() {
	var obs = new Obstacle();
	// Randomly left or right
	var side = Math.random() < 0.5 ? -1 : 1;
	obs.setSide(side);
	// Place near top of road, but not offscreen
	obs.setY(-120);
	obstacles.push(obs);
	game.addChild(obs);
}
// Helper: update score
function updateScore() {
	scoreTxt.setText(LK.getScore());
}
// Helper: reset game state
function resetGame() {
	// Remove all obstacles
	for (var i = 0; i < obstacles.length; ++i) {
		obstacles[i].destroy();
	}
	obstacles = [];
	car.resetPosition();
	car.speed = carBaseSpeed;
	obstacleInterval = 90;
	passedObstacles = 0;
	ticksSinceLastObstacle = 0;
	// Reset dotted lines to initial positions
	for (var i = 0; i < dottedLines.length; ++i) {
		dottedLines[i].x = 2048 / 2;
		dottedLines[i].y = -dottedLineHeight / 2 + i * dottedLineSpacing;
	}
	LK.setScore(0);
	updateScore();
	gameOver = false;
}
// Touch/tap: switch direction (visual only)
game.down = function (x, y, obj) {
	if (gameOver) return;
	var newDir = car.direction === 1 ? -1 : 1;
	car.setDirection(newDir);
};
// Main game loop
game.update = function () {
	if (gameOver) return;
	// Move car
	car.moveForward();
	// (Drifting line update removed)
	// Keep car inside road bounds
	var roadCenter = 2048 / 2;
	var roadWidth = 600;
	var carHalfW = car.width / 2;
	if (car.x < roadCenter - roadWidth / 2 + carHalfW) {
		car.x = roadCenter - roadWidth / 2 + carHalfW;
	}
	if (car.x > roadCenter + roadWidth / 2 - carHalfW) {
		car.x = roadCenter + roadWidth / 2 - carHalfW;
	}
	// Move dotted lines down
	for (var i = 0; i < dottedLines.length; ++i) {
		var dot = dottedLines[i];
		dot.y += car.speed;
		// If offscreen at bottom, move to top
		if (dot.y > 2732 + dottedLineHeight / 2) {
			// Find highest y among all dots
			var maxY = -Infinity;
			for (var j = 0; j < dottedLines.length; ++j) {
				if (dottedLines[j].y > maxY) maxY = dottedLines[j].y;
			}
			dot.y = maxY - dottedLineSpacing * (dottedLines.length - 1);
			// Place at top, spaced above highest
			dot.y = maxY - dottedLineSpacing + car.speed;
		}
	}
	// Move obstacles straight down
	for (var i = obstacles.length - 1; i >= 0; --i) {
		var obs = obstacles[i];
		obs.y += car.speed;
		// Check for collision
		if (!gameOver && car.intersects(obs)) {
			LK.effects.flashScreen(0xff0000, 800);
			gameOver = true;
			LK.showGameOver();
			return;
		}
		// Check if passed (obstacle is below car, and not already counted)
		if (!obs.passed && obs.y > car.y) {
			obs.passed = true;
			LK.setScore(LK.getScore() + 5);
			updateScore();
			passedObstacles += 1;
			// Speed up every N obstacles
			if (passedObstacles % speedIncreaseEvery === 0 && car.speed < carMaxSpeed) {
				car.speed += 2;
				if (obstacleInterval > minObstacleInterval) {
					obstacleInterval -= 6;
					if (obstacleInterval < minObstacleInterval) obstacleInterval = minObstacleInterval;
				}
			}
		}
		// Remove if offscreen
		if (obs.y > 2732 + 120 || obs.x < 0 - 200 || obs.x > 2048 + 200) {
			obs.destroy();
			obstacles.splice(i, 1);
		}
	}
	// Spawn new obstacles
	ticksSinceLastObstacle += 1;
	if (ticksSinceLastObstacle >= obstacleInterval) {
		spawnObstacle();
		ticksSinceLastObstacle = 0;
	}
};
// Reset game on game over
game.on('reset', function () {
	resetGame();
});
// Initial state
resetGame();

===================================================================
--- original.js
+++ change.js
@@ -154,9 +154,10 @@
 var dottedLineSpacing = 320;
 var numDottedLines = Math.ceil(2732 / dottedLineSpacing) + 2; // enough to cover screen + buffer
 for (var i = 0; i < numDottedLines; ++i) {
 	var dot = new DottedLine();
-	// Spawn at top middle, spaced downwards
+	// Always spawn at the top middle, spaced downwards
+	dot.x = 2048 / 2;
 	dot.y = -dottedLineHeight / 2 + i * dottedLineSpacing;
 	dottedLines.push(dot);
 	game.addChild(dot);
 }
@@ -197,9 +198,10 @@
 	passedObstacles = 0;
 	ticksSinceLastObstacle = 0;
 	// Reset dotted lines to initial positions
 	for (var i = 0; i < dottedLines.length; ++i) {
-		dottedLines[i].y = i * dottedLineSpacing - dottedLineHeight;
+		dottedLines[i].x = 2048 / 2;
+		dottedLines[i].y = -dottedLineHeight / 2 + i * dottedLineSpacing;
 	}
 	LK.setScore(0);
 	updateScore();
 	gameOver = false;