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

/**** 
* Classes
****/ 
// Block class
var Block = Container.expand(function () {
	var self = Container.call(this);
	// Properties: type ('grass', 'dirt', 'stone'), gridX, gridY
	self.type = 'grass';
	self.gridX = 0;
	self.gridY = 0;
	self.asset = null;
	self.setType = function (type) {
		self.type = type;
		if (self.asset) {
			self.removeChild(self.asset);
		}
		var assetId = 'block_' + type;
		self.asset = self.attachAsset(assetId, {
			anchorX: 0.5,
			anchorY: 0.5
		});
	};
	// For block selection highlight
	self.setSelected = function (selected) {
		if (selected) {
			if (!self.selector) {
				self.selector = self.attachAsset('selector', {
					anchorX: 0.5,
					anchorY: 0.5
				});
				self.selector.alpha = 0.3;
				self.setChildIndex(self.selector, self.children.length - 1);
			}
		} else {
			if (self.selector) {
				self.removeChild(self.selector);
				self.selector = null;
			}
		}
	};
	// Remove block from world
	self.removeBlock = function () {
		self.destroy();
	};
	return self;
});
// Sun/Moon class for day-night cycle
var DayNightObject = Container.expand(function () {
	var self = Container.call(this);
	self.asset = null;
	self.setType = function (type) {
		if (self.asset) {
			self.removeChild(self.asset);
		}
		self.asset = self.attachAsset(type, {
			anchorX: 0.5,
			anchorY: 0.5
		});
	};
	return self;
});
// Herobrine class
var Herobrine = Container.expand(function () {
	var self = Container.call(this);
	// Use a unique color for Herobrine (white eyes, brown body)
	self.body = self.attachAsset('block_wood', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.body.width = 120;
	self.body.height = 120;
	// Add white "eyes" as two small blocks
	self.eyeLeft = self.attachAsset('block_stone', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.eyeLeft.width = 24;
	self.eyeLeft.height = 24;
	self.eyeLeft.x = -24;
	self.eyeLeft.y = -24;
	self.eyeLeft.tint = 0xffffff;
	self.eyeRight = self.attachAsset('block_stone', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.eyeRight.width = 24;
	self.eyeRight.height = 24;
	self.eyeRight.x = 24;
	self.eyeRight.y = -24;
	self.eyeRight.tint = 0xffffff;
	return self;
});
// InventoryButton class
var InventoryButton = Container.expand(function () {
	var self = Container.call(this);
	self.type = 'grass';
	self.asset = null;
	self.setType = function (type) {
		self.type = type;
		if (self.asset) {
			self.removeChild(self.asset);
		}
		var assetId = 'block_' + type;
		self.asset = self.attachAsset(assetId, {
			anchorX: 0.5,
			anchorY: 0.5
		});
		self.asset.width = 120;
		self.asset.height = 120;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87ceeb // Sky blue for day
});

/**** 
* Game Code
****/ 
// --- World/grid setup ---
// Block assets (3 types: grass, dirt, stone)
// Selector highlight
// Sun and moon for day-night cycle
var GRID_COLS = 12;
var GRID_ROWS = 16;
var BLOCK_SIZE = 120;
var GRID_OFFSET_X = Math.floor((2048 - GRID_COLS * BLOCK_SIZE) / 2);
var GRID_OFFSET_Y = 350;
var worldBlocks = []; // 2D array [row][col] of Block or null
// --- Inventory setup ---
var blockTypes = ['grass', 'dirt', 'stone', 'sand', 'wood', 'water'];
var selectedBlockType = 'grass';
var inventoryButtons = [];
var inventoryY = 80;
// --- Selection ---
var selectedBlock = null;
var dragBlock = null;
var dragStart = null;
// --- Day-night cycle ---
var isDay = true;
var dayNightObj = new DayNightObject();
var dayNightTimer = 0;
var DAY_DURATION = 1200; // ticks (20 seconds)
var NIGHT_DURATION = 900; // ticks (15 seconds)
var dayNightState = 'day'; // 'day' or 'night'
// --- GUI: Inventory bar ---
for (var i = 0; i < blockTypes.length; i++) {
	var btn = new InventoryButton();
	btn.setType(blockTypes[i]);
	// Move inventory to the left side, vertically stacked, leaving top margin for menu
	btn.x = 100; // left margin, avoid top left 100x100
	btn.y = 120 + i * 160; // start below top menu, vertical spacing
	btn.type = blockTypes[i];
	// Highlight selected
	if (blockTypes[i] === selectedBlockType) {
		btn.asset.alpha = 1.0;
	} else {
		btn.asset.alpha = 0.5;
	}
	// Touch event
	(function (btn, i) {
		btn.down = function (x, y, obj) {
			selectedBlockType = btn.type;
			for (var j = 0; j < inventoryButtons.length; j++) {
				inventoryButtons[j].asset.alpha = inventoryButtons[j].type === selectedBlockType ? 1.0 : 0.5;
			}
		};
	})(btn, i);
	LK.gui.top.addChild(btn);
	inventoryButtons.push(btn);
}
// --- World: Initialize grid with some blocks (ground layer) ---
for (var row = 0; row < GRID_ROWS; row++) {
	worldBlocks[row] = [];
	for (var col = 0; col < GRID_COLS; col++) {
		if (row >= GRID_ROWS - 3) {
			// Bottom 3 rows: dirt, stone, stone
			var type = row === GRID_ROWS - 3 ? 'dirt' : 'stone';
			var block = new Block();
			block.setType(type);
			block.gridX = col;
			block.gridY = row;
			block.x = GRID_OFFSET_X + col * BLOCK_SIZE + BLOCK_SIZE / 2;
			block.y = GRID_OFFSET_Y + row * BLOCK_SIZE + BLOCK_SIZE / 2;
			worldBlocks[row][col] = block;
			game.addChild(block);
		} else if (row === GRID_ROWS - 4) {
			// Top of ground: grass
			var block = new Block();
			block.setType('grass');
			block.gridX = col;
			block.gridY = row;
			block.x = GRID_OFFSET_X + col * BLOCK_SIZE + BLOCK_SIZE / 2;
			block.y = GRID_OFFSET_Y + row * BLOCK_SIZE + BLOCK_SIZE / 2;
			worldBlocks[row][col] = block;
			game.addChild(block);
		} else {
			worldBlocks[row][col] = null;
		}
	}
}
// --- Day/Night object (sun/moon) ---
dayNightObj.setType('sun');
dayNightObj.x = 2048 / 2;
dayNightObj.y = 180;
game.addChild(dayNightObj);
// --- Herobrine: Add to world, standing on the ground ---
var herobrine = new Herobrine();
herobrine.x = GRID_OFFSET_X + Math.floor(GRID_COLS / 2) * BLOCK_SIZE + BLOCK_SIZE / 2;
herobrine.y = GRID_OFFSET_Y + (GRID_ROWS - 4) * BLOCK_SIZE + BLOCK_SIZE / 2 - 60; // Stand on grass
game.addChild(herobrine);
// --- Helper: Get grid cell from x,y ---
function getGridCell(x, y) {
	var col = Math.floor((x - GRID_OFFSET_X) / BLOCK_SIZE);
	var row = Math.floor((y - GRID_OFFSET_Y) / BLOCK_SIZE);
	if (col < 0 || col >= GRID_COLS || row < 0 || row >= GRID_ROWS) return null;
	return {
		col: col,
		row: row
	};
}
// --- Helper: Place block ---
function placeBlock(col, row, type) {
	if (col < 0 || col >= GRID_COLS || row < 0 || row >= GRID_ROWS) return;
	if (worldBlocks[row][col]) return; // Occupied
	var block = new Block();
	block.setType(type);
	block.gridX = col;
	block.gridY = row;
	block.x = GRID_OFFSET_X + col * BLOCK_SIZE + BLOCK_SIZE / 2;
	block.y = GRID_OFFSET_Y + row * BLOCK_SIZE + BLOCK_SIZE / 2;
	worldBlocks[row][col] = block;
	game.addChild(block);
}
// --- Helper: Remove block ---
function removeBlock(col, row) {
	if (col < 0 || col >= GRID_COLS || row < 0 || row >= GRID_ROWS) return;
	var block = worldBlocks[row][col];
	if (block) {
		block.removeBlock();
		worldBlocks[row][col] = null;
	}
}
// --- Helper: Move block ---
function moveBlock(fromCol, fromRow, toCol, toRow) {
	if (fromCol < 0 || fromCol >= GRID_COLS || fromRow < 0 || fromRow >= GRID_ROWS) return;
	if (toCol < 0 || toCol >= GRID_COLS || toRow < 0 || toRow >= GRID_ROWS) return;
	if (worldBlocks[toRow][toCol]) return; // Target occupied
	var block = worldBlocks[fromRow][fromCol];
	if (!block) return;
	worldBlocks[toRow][toCol] = block;
	worldBlocks[fromRow][fromCol] = null;
	block.gridX = toCol;
	block.gridY = toRow;
	var targetX = GRID_OFFSET_X + toCol * BLOCK_SIZE + BLOCK_SIZE / 2;
	var targetY = GRID_OFFSET_Y + toRow * BLOCK_SIZE + BLOCK_SIZE / 2;
	tween(block, {
		x: targetX,
		y: targetY
	}, {
		duration: 120,
		easing: tween.cubicOut
	});
}
// --- Touch/drag logic ---
game.down = function (x, y, obj) {
	// Ignore touches on inventory bar
	if (y < inventoryY + 160) return;
	var cell = getGridCell(x, y);
	if (!cell) return;
	var block = worldBlocks[cell.row][cell.col];
	if (block) {
		// Select block for move or remove
		selectedBlock = block;
		dragBlock = block;
		dragStart = {
			col: cell.col,
			row: cell.row
		};
		block.setSelected(true);
	} else {
		// Place block
		placeBlock(cell.col, cell.row, selectedBlockType);
	}
};
game.move = function (x, y, obj) {
	if (!dragBlock) return;
	var cell = getGridCell(x, y);
	if (!cell) return;
	// Highlight block under finger
	for (var row = 0; row < GRID_ROWS; row++) {
		for (var col = 0; col < GRID_COLS; col++) {
			var b = worldBlocks[row][col];
			if (b && b !== dragBlock) b.setSelected(false);
		}
	}
	var block = worldBlocks[cell.row][cell.col];
	if (block && block === dragBlock) {
		block.setSelected(true);
	}
};
game.up = function (x, y, obj) {
	if (!dragBlock) return;
	var cell = getGridCell(x, y);
	if (!cell) {
		dragBlock.setSelected(false);
		dragBlock = null;
		dragStart = null;
		return;
	}
	// If released on empty cell, move block
	if (!worldBlocks[cell.row][cell.col]) {
		moveBlock(dragStart.col, dragStart.row, cell.col, cell.row);
	} else if (cell.col === dragStart.col && cell.row === dragStart.row) {
		// If tap on same block, remove it
		removeBlock(cell.col, cell.row);
	}
	dragBlock.setSelected(false);
	dragBlock = null;
	dragStart = null;
};
// --- Day/Night cycle logic ---
function updateDayNightCycle() {
	dayNightTimer++;
	if (dayNightState === 'day' && dayNightTimer > DAY_DURATION) {
		// Switch to night
		dayNightState = 'night';
		dayNightTimer = 0;
		// Animate sun out, moon in
		tween(dayNightObj, {
			y: 3200
		}, {
			duration: 800,
			easing: tween.cubicIn,
			onFinish: function onFinish() {
				dayNightObj.setType('moon');
				dayNightObj.y = -200;
				tween(dayNightObj, {
					y: 180
				}, {
					duration: 800,
					easing: tween.cubicOut
				});
			}
		});
		// Darken background
		tween(game, {
			backgroundColor: 0x222244
		}, {
			duration: 1200,
			easing: tween.linear
		});
	} else if (dayNightState === 'night' && dayNightTimer > NIGHT_DURATION) {
		// Switch to day
		dayNightState = 'day';
		dayNightTimer = 0;
		// Animate moon out, sun in
		tween(dayNightObj, {
			y: 3200
		}, {
			duration: 800,
			easing: tween.cubicIn,
			onFinish: function onFinish() {
				dayNightObj.setType('sun');
				dayNightObj.y = -200;
				tween(dayNightObj, {
					y: 180
				}, {
					duration: 800,
					easing: tween.cubicOut
				});
			}
		});
		// Brighten background
		tween(game, {
			backgroundColor: 0x87ceeb
		}, {
			duration: 1200,
			easing: tween.linear
		});
	}
}
// --- Game update loop ---
game.update = function () {
	updateDayNightCycle();
	// Gravity for sand and water blocks
	for (var row = GRID_ROWS - 2; row >= 0; row--) {
		for (var col = 0; col < GRID_COLS; col++) {
			var block = worldBlocks[row][col];
			if (block && (block.type === 'sand' || block.type === 'water')) {
				var belowRow = row + 1;
				if (belowRow < GRID_ROWS && !worldBlocks[belowRow][col]) {
					moveBlock(col, row, col, belowRow);
				}
			}
		}
	}
};

===================================================================
--- original.js
+++ change.js
@@ -125,12 +125,12 @@
 
 /**** 
 * Game Code
 ****/ 
-// Sun and moon for day-night cycle
-// Selector highlight
-// Block assets (3 types: grass, dirt, stone)
 // --- World/grid setup ---
+// Block assets (3 types: grass, dirt, stone)
+// Selector highlight
+// Sun and moon for day-night cycle
 var GRID_COLS = 12;
 var GRID_ROWS = 16;
 var BLOCK_SIZE = 120;
 var GRID_OFFSET_X = Math.floor((2048 - GRID_COLS * BLOCK_SIZE) / 2);
@@ -391,16 +391,16 @@
 }
 // --- Game update loop ---
 game.update = function () {
 	updateDayNightCycle();
-	// Gravity: let unsupported blocks fall down
+	// Gravity for sand and water blocks
 	for (var row = GRID_ROWS - 2; row >= 0; row--) {
 		for (var col = 0; col < GRID_COLS; col++) {
 			var block = worldBlocks[row][col];
-			if (block && !worldBlocks[row + 1][col]) {
-				// Only move if not being dragged
-				if (dragBlock !== block) {
-					moveBlock(col, row, col, row + 1);
+			if (block && (block.type === 'sand' || block.type === 'water')) {
+				var belowRow = row + 1;
+				if (belowRow < GRID_ROWS && !worldBlocks[belowRow][col]) {
+					moveBlock(col, row, col, belowRow);
 				}
 			}
 		}
 	}