Witam. Przychodzę z pewnym problemem. Dlaczego budynek nie pojawia się w odpowiednim miejscu?

<!DOCTYPE html>
<html lang="pl">
	<head>
		<meta charset="utf-8">
		<title>Canvas</title>
		<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
		<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
		<script type="text/javascript">
				window.onload = function() {
					var canvas = document.getElementById('canvas');
					var context = canvas.getContext('2d');
					
					var grid = {
						width: 5,
						height: 5
					}
						
					var tile = new Image();
					tile.src = 'img/tile.png';
					
					var building = new Image();
					building.src = 'img/icecream.png';
						
					var build = [];
						
					var oldBuild = [];
						
					$('#draggable').draggable();
					$('#draggable2').draggable();
						
					var buildingName = '';
						
					$.ajax({
						type     : "GET",
						url      : "dane.php",
						async	 : false,
						success : function(msg) {
							oldBuild = msg;
						}
					});
						
					$('#canvas').droppable({
						drop: function( event, ui) {
							var gridOffsetX = (canvas.width / 2) - (tile.width / 2); //Bierzemy poprawkę na wyśrodkowanie siatki
							var gridOffsetY = 0;
							
							var col = (event.clientY - gridOffsetY) * 2;
							col = ((gridOffsetX + col) - event.clientX) / 2;
											
							var row = ((event.clientX + col) - tile.height) - gridOffsetX;
					
							row = Math.round(row / tile.height);
							col = Math.round(col / tile.height);
								
							if (row >= 0 && 
								col >= 0 && 
								row <= grid.width &&
								col <= grid.height) {
								build[row] = (build[row] === undefined) ? [] : build[row];
								
								build[row][col] = 1;
								buildingName = ui.draggable.attr('date-name');
								$.ajax({
									type     : "GET",
									url      : "zapisz.php",
									data     : {
											name: buildingName,
											row: row,
											col: col
									},
									success : function(msg) {
										alert(msg);
									}
								});
								draw();
							}
						}
					});
						
					function draw() {
						context.clearRect (0, 0, canvas.width, canvas.height);
						for (row = 0; row < grid.width; row++){
							for (col = 0; col < grid.height; col++){
								var tilePositionX = (row-col) * (tile.width/2);
								tilePositionX += (canvas.width / 2) - (tile.width / 2);
								var tilePositionY = (row+col) * (tile.height/2);
								if (oldBuild[row] && oldBuild[row][col]){
									tilePositionY -= building.height - tile.height;
									tilePositionX -= (building.width / 2) - (tile.width / 2);
									context.drawImage(building, Math.round(tilePositionX), Math.round(tilePositionY), building.width, building.height);
								}
								else if (build[row] != null && build[row][col] != null) {
									tilePositionY -= building.height - tile.height;
									tilePositionX -= (building.width / 2) - (tile.width / 2);
									context.drawImage(building, Math.round(tilePositionX), Math.round(tilePositionY), building.width, building.height);
								}
								else
								{
									context.drawImage(tile, tilePositionX, tilePositionY);
								}
							}
						}
						alert(build);
						alert(oldBuild);
					}
					draw();
				}
		</script>
	</head>
	<body>
		<div id='container'>
		<canvas id="canvas" width="600" height="600">
		brak
		</canvas>
		</div>
		<div id='draggable' style='width: 128px; height: 111px;' date-name='elem' ><img src='img/icecream.png'></div>
		<div id='draggable2' style='width: 128px; height: 111px;' date-name='elem2' ><img src='img/icecream.png'></div>
	</body>
</html>

Plik dane.php

<?php
$serwer = 'localhost';
$uzytkownik = 'root';
$haslo = '';
 
//ustanawiamy połączenie
$polaczenie = mysql_connect($serwer, $uzytkownik, $haslo);
if(!$polaczenie)
{
    die('Błąd połączenia: ' . mysql_error());
}
 
//wybieramy bazę
mysql_select_db('metropoliss', $polaczenie);
 
//umieszczamy nowy wpis w tabeli
$row = mysql_real_escape_string($_GET['row']);
$col = mysql_real_escape_string($_GET['col']);
$name = mysql_real_escape_string($_GET['name']);

$sql = mysql_query("SELECT * FROM test");
$return=[];
while($RES = mysql_fetch_array($sql))
{
    if(!isset($return[$RES['row']]))
    $return[$RES['row']]=[];
    $return[$RES['row']][$RES['col']]= true; //albo rodzaj budynku
}
echo json_encode($return, JSON_FORCE_OBJECT);
 
mysql_close($polaczenie);
?>