triangulate.php

<html>
<head>
	<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M" crossorigin="anonymous">
	<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.11.0/umd/popper.min.js" integrity="sha384-b/U6ypiBEHpOf/4+1nzFpr53nxSS+GLCkfwBdFNTxtclqqenISfwAzpKaMNFNmj4" crossorigin="anonymous"></script>
	<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/js/bootstrap.min.js" integrity="sha384-h0AbiXch4ZDo7tp9hKZ4TsHbi047NrKGLO3SEJAg45jXxnGIfYzk4Si90RDIqNm1" crossorigin="anonymous"></script>
	<script>
		$(document).ready(function() {
			var system = 1;
			$('#add').click(function(){
				system++;
				str = '<div class="row" id="system'+system+'"><div class="col-md-3 ml-md-auto"><div class="input-group"><span class="input-group-addon">X</span><input type="text" class="form-control" aria-label="X Coordinate" name="x['+system+']" required></div></div><div class="col-md-3"><div class="input-group"><span class="input-group-addon">Y</span><input type="text" class="form-control" aria-label="Y Coordinate" name="y['+system+']" required></div></div><div class="col-md-3"><div class="input-group mr-md-auto"><span class="input-group-addon">Distance</span><input type="text" class="form-control" aria-label="Target distance" name="z['+system+']" required></div></div><div class="col-md-2 mr-md-auto"><a href="#" class="btn btn-danger delete" id="delete'+system+'">Delete</a></div><br /><br /></div>';
				$('#systems').append(str);
			});	

			$("#systems").delegate(".delete", "click", function() {
				$(this).parent().parent().remove();
				return false;  
			});
		});
	</script>
</head>
<body style="background-color:#212529;">
	<div class="container">		
		<div class="card text-center bg-dark text-white">
			<div class="card-body">
				<h4 class="card-title">Triangulator</h4>
				<form method="post">
					<div id="systems">
						<div class="row" id="system1">
							<div class="col-md-3 ml-md-auto">
								<div class="input-group">
									<span class="input-group-addon">X</span>
									<input type="text" class="form-control" aria-label="X Coordinate" name="x[1]" required>
								</div><!-- /.input-group -->
							</div><!-- /.col-md-3 -->
							<div class="col-md-3">
								<div class="input-group">
									<span class="input-group-addon">Y</span>
									<input type="text" class="form-control" aria-label="Y Coordinate" name="y[1]" required>
								</div><!-- /.input-group -->
							</div><!-- /.col-md-3 -->
							<div class="col-md-3">
								<div class="input-group">
									<span class="input-group-addon">Distance</span>
									<input type="text" class="form-control" aria-label="Target distance" name="z[1]" required>
								</div><!-- /.input-group -->
							</div><!-- /.col-md-3 -->
							<div class="col-md-2 mr-md-auto">
								<a href="#" class="btn btn-success" id="add">Add System</a>
							</div><!-- /.col-md-2 -->
							<br />
							<br />
						</div><!-- /.row /#system1 -->
					</div><!-- /#systems -->
					<div class="row">
						<div class="col ml-md-auto mr-md-auto">
							<input class="btn btn-primary" id="triangulate" type="submit" name="submit" value="Triangulate">
						</div><!-- /.col -->
					</div><!-- /.row -->
				</form>
			</div><!-- /.card-body -->
		</div><!-- /.card -->
		<br/>

		<?php
			function compare_values($v1, $v2) {
				if ($v1===$v2) { return 0; }
				if ($v1 > $v2) { return 1; }
				return -1;
			}

			if(isset($_POST['submit'])) {
				$pingers = array();
				foreach($_POST['x'] as $pinger => $coordinate) {
					$pingers[$pinger]['x'] = $_POST['x'][$pinger];
					$pingers[$pinger]['y'] = $_POST['y'][$pinger];
					$pingers[$pinger]['z'] = $_POST['z'][$pinger];
				}
				$sector_groups = array();
				foreach($pingers as $pinger => $value) {
					$set = 0;
					for($i = 0; $i < $value['z']; $i++) {
						$sector_groups[$pinger][$set]['x'] = $value['x'] + $value['z'] - $i;
						$sector_groups[$pinger][$set]['y'] = $value['y'] + $i;
						$set++;
						
						$sector_groups[$pinger][$set]['x'] = $value['x'] - $value['z'] + $i;
						$sector_groups[$pinger][$set]['y'] = $value['y'] - $i;
						$set++;

						$sector_groups[$pinger][$set]['x'] = $value['x'] - $i;
						$sector_groups[$pinger][$set]['y'] = $value['y'] + $value['z'] - $i;
						$set++;
						
						$sector_groups[$pinger][$set]['x'] = $value['x'] + $i;
						$sector_groups[$pinger][$set]['y'] = $value['y'] - $value['z'] + $i;
						$set++;
					}
				}

				$possible_sectors = array_pop($sector_groups);
				
				if(count($sector_groups) > 0) {
					foreach($sector_groups as $sector) {
						$possible_sectors = array_uintersect($possible_sectors, $sector, "compare_values");
					}
				}
		?>
				
		<table class="table table-inverse table-bordered table-hover">	
			<thead>
				<tr>
					<th>#</th>
					<th>X</th>
					<th>Y</th>
				</tr>
			</thead>
			<tbody>
				<?php
					$i = 1;
					foreach($possible_sectors as $sector) {
						echo "<tr>";
						echo "<th>Potential #$i</th>";
						echo "<td>".$sector['x']."</td>";
						echo "<td>".$sector['y']."</td>";
						echo "</tr>";
						$i++;
					}
				?>
			</tbody>
		</table>
		<?php
			}
		?>
	</div><!-- /.container -->
</body>
</html>