/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");
var storage = LK.import("@upit/storage.v1", {
	worldData: "undefined",
	playerPosition: {
		x: 1024,
		y: 1600
	},
	inventory: {}
});

/**** 
* Classes
****/ 
var Block = Container.expand(function (type, size) {
	var self = Container.call(this);
	self.type = type;
	self.size = size || 64;
	var graphics = self.attachAsset(type, {
		anchorX: 0.5,
		anchorY: 0.5,
		width: self.size,
		height: self.size
	});
	self.down = function (x, y, obj) {
		if (currentTool === 'break') {
			self.breakBlock();
		}
	};
	self.breakBlock = function () {
		// Add to inventory
		inventory[self.type] = (inventory[self.type] || 0) + 1;
		updateInventoryDisplay();
		// Play break sound
		LK.getSound('break').play();
		// Remove from world
		var gridX = Math.floor(self.x / blockSize);
		var gridY = Math.floor(self.y / blockSize);
		if (worldData[gridY] && worldData[gridY][gridX]) {
			worldData[gridY][gridX] = null;
			self.destroy();
		}
		// Save world data
		storage.worldData = worldData;
	};
	return self;
});
var Button = Container.expand(function (text, callback) {
	var self = Container.call(this);
	var background = self.attachAsset('buttonBg', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.buttonText = new Text2(text, {
		size: 36,
		fill: 0xFFFFFF
	});
	self.buttonText.anchor.set(0.5, 0.5);
	self.addChild(self.buttonText);
	self.callback = callback;
	self.down = function (x, y, obj) {
		if (self.callback) {
			self.callback();
		}
	};
	return self;
});
var InventorySlot = Container.expand(function (index, type) {
	var self = Container.call(this);
	self.index = index;
	self.type = type;
	var background = self.attachAsset('inventorySlot', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	if (type) {
		var blockIcon = self.attachAsset(type, {
			anchorX: 0.5,
			anchorY: 0.5,
			width: 60,
			height: 60
		});
	}
	self.countText = new Text2("0", {
		size: 24,
		fill: 0xFFFFFF
	});
	self.countText.anchor.set(1, 1);
	self.countText.x = 30;
	self.countText.y = 30;
	self.addChild(self.countText);
	self.updateCount = function (count) {
		self.countText.setText(count.toString());
	};
	self.down = function (x, y, obj) {
		selectInventorySlot(self.index);
	};
	return self;
});
var MainMenu = Container.expand(function () {
	var self = Container.call(this);
	// Create a semi-transparent background overlay
	var overlay = LK.getAsset('buttonBg', {
		anchorX: 0.5,
		anchorY: 0.5,
		width: 2048,
		height: 2732,
		alpha: 0.7
	});
	overlay.tint = 0x000000;
	self.addChild(overlay);
	// Game title
	self.title = new Text2("Pixel Realms", {
		size: 120,
		fill: 0xFFFFFF
	});
	self.title.anchor.set(0.5, 0.5);
	self.title.x = 2048 / 2;
	self.title.y = 800;
	self.addChild(self.title);
	// Start game button
	self.startButton = new Button("Start Game", function () {
		self.hide();
		gameStarted = true;
		initializeWorld();
		setupUI();
	});
	self.startButton.x = 2048 / 2;
	self.startButton.y = 1200;
	self.addChild(self.startButton);
	// Add animated elements
	self.show = function () {
		self.visible = true;
		// Reset positions for animation
		self.title.y = 600;
		self.title.alpha = 0;
		self.startButton.y = 1300;
		self.startButton.alpha = 0;
		// Animate title
		tween(self.title, {
			y: 800,
			alpha: 1
		}, {
			duration: 800,
			easing: tween.easeOutBack
		});
		// Animate button with slight delay
		tween(self.startButton, {
			y: 1200,
			alpha: 1
		}, {
			duration: 800,
			easing: tween.easeOutBack
		});
	};
	self.hide = function () {
		// Animate out
		tween(self.title, {
			y: 600,
			alpha: 0
		}, {
			duration: 500,
			easing: tween.easeInBack
		});
		tween(self.startButton, {
			y: 1300,
			alpha: 0
		}, {
			duration: 500,
			easing: tween.easeInBack,
			onFinish: function onFinish() {
				self.visible = false;
			}
		});
	};
	return self;
});
var Player = Container.expand(function () {
	var self = Container.call(this);
	var graphics = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 1,
		width: 60,
		height: 120
	});
	// Movement properties
	self.speed = 5;
	self.velocity = {
		x: 0,
		y: 0
	};
	self.gravity = 0.5;
	self.jumping = false;
	self.grounded = false;
	self.move = function (direction) {
		if (direction === 'left') {
			self.velocity.x = -self.speed;
		} else if (direction === 'right') {
			self.velocity.x = self.speed;
		}
	};
	self.stopMove = function () {
		self.velocity.x = 0;
	};
	self.jump = function () {
		if (self.grounded) {
			self.velocity.y = -12;
			self.grounded = false;
			self.jumping = true;
		}
	};
	self.update = function () {
		// Apply gravity
		if (!self.grounded) {
			self.velocity.y += self.gravity;
		}
		// Update position
		self.x += self.velocity.x;
		self.y += self.velocity.y;
		// Check for ground collision
		var gridX = Math.floor(self.x / blockSize);
		var gridY = Math.floor((self.y + 10) / blockSize);
		// Simple collision check with the block below
		if (worldData[gridY] && worldData[gridY][gridX] && worldData[gridY][gridX] !== 'water') {
			if (self.velocity.y > 0) {
				self.y = gridY * blockSize - 10;
				self.velocity.y = 0;
				self.grounded = true;
				self.jumping = false;
			}
		} else {
			self.grounded = false;
		}
		// Update camera to follow player
		updateCamera();
		// Save player position periodically
		if (LK.ticks % 60 === 0) {
			storage.playerPosition = {
				x: self.x,
				y: self.y
			};
		}
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87CEEB // Sky blue background
});

/**** 
* Game Code
****/ 
// Game constants
var blockSize = 64;
var worldWidth = 64;
var worldHeight = 32;
var gravity = 0.5;
// Game state
var gameStarted = false;
var worldData = storage.worldData || generateWorld();
var inventory = storage.inventory || {
	"grass": 0,
	"stone": 0,
	"wood": 0,
	"water": 0
};
var currentTool = 'place'; // 'place' or 'break'
var selectedBlockType = 'grass';
var selectedInventorySlot = 0;
// Game containers
var worldContainer = new Container();
var uiContainer = new Container();
var inventoryContainer = new Container();
var toolbarContainer = new Container();
game.addChild(worldContainer);
game.addChild(uiContainer);
// Create player
var player = new Player();
player.x = storage.playerPosition ? storage.playerPosition.x : 1024;
player.y = storage.playerPosition ? storage.playerPosition.y : 1600;
worldContainer.addChild(player);
// Initialize world blocks
function initializeWorld() {
	// Clear any existing blocks
	while (worldContainer.children.length > 1) {
		// Keep player
		worldContainer.removeChildAt(1);
	}
	// Place blocks based on worldData
	for (var y = 0; y < worldData.length; y++) {
		for (var x = 0; x < worldData[y].length; x++) {
			if (worldData[y][x]) {
				var block = new Block(worldData[y][x], blockSize);
				block.x = x * blockSize + blockSize / 2;
				block.y = y * blockSize + blockSize / 2;
				worldContainer.addChild(block);
			}
		}
	}
}
// Generate a new world
function generateWorld() {
	var data = [];
	// Initialize with empty arrays
	for (var y = 0; y < worldHeight; y++) {
		data[y] = [];
		for (var x = 0; x < worldWidth; x++) {
			data[y][x] = null;
		}
	}
	// Generate terrain
	for (var x = 0; x < worldWidth; x++) {
		// Base ground height (with some randomness)
		var groundHeight = Math.floor(worldHeight * 0.7) + Math.floor(Math.random() * 4) - 2;
		// Generate ground layers
		for (var y = groundHeight; y < worldHeight; y++) {
			if (y === groundHeight) {
				data[y][x] = 'grass';
			} else if (y < groundHeight + 3) {
				data[y][x] = 'ground';
			} else {
				data[y][x] = Math.random() < 0.3 ? 'stone' : 'ground';
			}
		}
		// Add some trees
		if (Math.random() < 0.1) {
			var treeHeight = 3 + Math.floor(Math.random() * 2);
			for (var ty = 1; ty <= treeHeight; ty++) {
				if (groundHeight - ty >= 0) {
					data[groundHeight - ty][x] = 'wood';
				}
			}
		}
		// Add some water pools
		if (Math.random() < 0.05 && x > 0 && x < worldWidth - 2) {
			var poolWidth = 2 + Math.floor(Math.random() * 3);
			for (var wx = 0; wx < poolWidth && x + wx < worldWidth; wx++) {
				data[groundHeight][x + wx] = 'water';
				// Ensure the next iterations skip this area
				if (wx > 0) x++;
			}
		}
	}
	// Save the generated world
	storage.worldData = data;
	return data;
}
// Setup UI
function setupUI() {
	// Create inventory bar
	setupInventory();
	// Create tool selection buttons
	setupToolbar();
	// Create control buttons (left, right, jump)
	setupControls();
}
function setupInventory() {
	inventoryContainer = new Container();
	var blockTypes = ['grass', 'stone', 'wood', 'water'];
	var slotSpacing = 100;
	// Create the background for selected slot
	var selectedSlotBg = LK.getAsset('selectedSlot', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	inventoryContainer.addChild(selectedSlotBg);
	// Create inventory slots
	for (var i = 0; i < blockTypes.length; i++) {
		var slot = new InventorySlot(i, blockTypes[i]);
		slot.x = i * slotSpacing;
		slot.updateCount(inventory[blockTypes[i]] || 0);
		inventoryContainer.addChild(slot);
	}
	// Position the inventory at the top center
	inventoryContainer.x = 2048 / 2 - (blockTypes.length - 1) * slotSpacing / 2;
	inventoryContainer.y = 100;
	// Update selected slot visual
	updateSelectedSlot();
	LK.gui.top.addChild(inventoryContainer);
}
function setupToolbar() {
	toolbarContainer = new Container();
	// Place tool
	var placeToolBtn = new Button("Place", function () {
		currentTool = 'place';
		updateToolbarSelection();
	});
	placeToolBtn.x = 0;
	toolbarContainer.addChild(placeToolBtn);
	// Break tool
	var breakToolBtn = new Button("Break", function () {
		currentTool = 'break';
		updateToolbarSelection();
	});
	breakToolBtn.x = 250;
	toolbarContainer.addChild(breakToolBtn);
	// Position toolbar at bottom right
	toolbarContainer.x = 2048 - 400;
	toolbarContainer.y = 2732 - 100;
	LK.gui.bottomRight.addChild(toolbarContainer);
	// Update the initial tool selection
	updateToolbarSelection();
}
function setupControls() {
	var controlsContainer = new Container();
	// Left button
	var leftBtn = new Button("←", function () {
		player.move('left');
	});
	leftBtn.x = 0;
	controlsContainer.addChild(leftBtn);
	// Right button
	var rightBtn = new Button("→", function () {
		player.move('right');
	});
	rightBtn.x = 250;
	controlsContainer.addChild(rightBtn);
	// Jump button
	var jumpBtn = new Button("Jump", function () {
		player.jump();
	});
	jumpBtn.x = 500;
	controlsContainer.addChild(jumpBtn);
	// Position controls at bottom left
	controlsContainer.x = 200;
	controlsContainer.y = 2732 - 100;
	LK.gui.bottomLeft.addChild(controlsContainer);
}
function updateSelectedSlot() {
	var selectedSlotBg = inventoryContainer.getChildAt(0);
	var slot = inventoryContainer.getChildAt(selectedInventorySlot + 1);
	if (slot) {
		selectedSlotBg.x = slot.x;
		selectedSlotBg.y = slot.y;
		selectedBlockType = slot.type;
	}
}
function updateToolbarSelection() {
	var placeToolBtn = toolbarContainer.getChildAt(0);
	var breakToolBtn = toolbarContainer.getChildAt(1);
	if (currentTool === 'place') {
		placeToolBtn.buttonText.style.fill = "#FFFF00";
		breakToolBtn.buttonText.style.fill = "#FFFFFF";
	} else {
		placeToolBtn.buttonText.style.fill = "#FFFFFF";
		breakToolBtn.buttonText.style.fill = "#FFFF00";
	}
}
function selectInventorySlot(index) {
	selectedInventorySlot = index;
	updateSelectedSlot();
	// Play select sound
	LK.getSound('select').play();
}
function updateInventoryDisplay() {
	for (var i = 1; i < inventoryContainer.children.length; i++) {
		var slot = inventoryContainer.getChildAt(i);
		slot.updateCount(inventory[slot.type] || 0);
	}
}
function updateCamera() {
	// Calculate how much to offset the world to center the player
	var targetX = -player.x + 2048 / 2;
	var targetY = -player.y + 2732 / 2;
	// Add bounds to prevent seeing outside the world
	targetX = Math.min(0, Math.max(targetX, -(worldWidth * blockSize - 2048)));
	targetY = Math.min(0, Math.max(targetY, -(worldHeight * blockSize - 2732)));
	// Smooth camera movement
	worldContainer.x = targetX;
	worldContainer.y = targetY;
}
function placeBlock(x, y) {
	// Convert screen position to world position
	var worldX = x - worldContainer.x;
	var worldY = y - worldContainer.y;
	// Convert world position to grid position
	var gridX = Math.floor(worldX / blockSize);
	var gridY = Math.floor(worldY / blockSize);
	// Check if we have this block type in inventory
	if (inventory[selectedBlockType] <= 0) {
		return;
	}
	// Check if position is valid
	if (gridX < 0 || gridX >= worldWidth || gridY < 0 || gridY >= worldHeight) {
		return;
	}
	// Check if space is empty
	if (!worldData[gridY] || worldData[gridY][gridX] !== null) {
		return;
	}
	// Place the block
	worldData[gridY][gridX] = selectedBlockType;
	// Remove from inventory
	inventory[selectedBlockType]--;
	updateInventoryDisplay();
	// Create the block visually
	var block = new Block(selectedBlockType, blockSize);
	block.x = gridX * blockSize + blockSize / 2;
	block.y = gridY * blockSize + blockSize / 2;
	worldContainer.addChild(block);
	// Play place sound
	LK.getSound('place').play();
	// Save world data
	storage.worldData = worldData;
	storage.inventory = inventory;
}
// Game event handlers
game.down = function (x, y, obj) {
	if (currentTool === 'place') {
		placeBlock(x, y);
	}
};
// Main game loop
game.update = function () {
	// Only update game elements if the game has started
	if (gameStarted) {
		// Update player
		player.update();
		// Save game data periodically
		if (LK.ticks % 300 === 0) {
			storage.worldData = worldData;
			storage.inventory = inventory;
		}
	}
};
// Create and show main menu
var mainMenu = new MainMenu();
mainMenu.x = 0;
mainMenu.y = 0;
game.addChild(mainMenu);
mainMenu.show();
// Start background music
LK.playMusic('bgmusic');

===================================================================
--- original.js
+++ change.js
@@ -490,9 +490,9 @@
 	if (gridX < 0 || gridX >= worldWidth || gridY < 0 || gridY >= worldHeight) {
 		return;
 	}
 	// Check if space is empty
-	if (worldData[gridY][gridX] !== null) {
+	if (!worldData[gridY] || worldData[gridY][gridX] !== null) {
 		return;
 	}
 	// Place the block
 	worldData[gridY][gridX] = selectedBlockType;