Triangle Constrained Draggable Selector

Example demonstrating the constraint of a jQuery Ui Draggable Selector to a triangular area using the JS 2D Graph library

HTML

<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script src="https://code.jquery.com/ui/1.12.0/jquery-ui.min.js"></script>
<script src="https://borgboyone.github.io/Graph/js/Graph.js"></script>
<body>
	<div class="content">
		<div class="map">
			<svg height="100%" width="100%">
    			<polygon points="10,10 246,128 40,232" style="fill:cyan;" />
			</svg>
			<div class="map-selector">
			</div>
		</div>
	</div>
</body>

CSS

.content {
  width:512px;
  height:512px;
  margin: 0 auto;
  display: flex;
  justify-content: space-around;
  align-items: center;
}
.map {
  width:256px;
  height:256px;
  position:relative;
}
.map-selector {
  display:inline-block;
  width:15px;
  height:15px;
  border: 1px solid #333;
  border-radius:50%;
  position:absolute;
  top:128px;
  left:128px;
  margin-top: -8px;
  margin-left: -8px;
  background: red;
}

JavaScript

jQuery(document).ready(function($) {
			var points = $('polygon').attr('points').trim().split(' ').map(function(vertex) { var coordinates = vertex.split(','); return new aw.Graph.Point(Number(coordinates[0]), Number(-coordinates[1])); });
			//var triangle = new aw.Graph.Polygon([new aw.Graph.Point(10, -10), new aw.Graph.Point(246, -128), new aw.Graph.Point(40, -232)]);
			var triangle = new aw.Graph.Polygon(points);
			$('.map-selector').draggable({
				containment: '.map',
				drag: function (event, ui) {
					var left = ui.position.left, top = -ui.position.top;
					var constrained = triangle.constrain(new aw.Graph.Point(left, top));
					ui.position.left = constrained.x; ui.position.top = -constrained.y;
          console.log(ui.position);
				}
			});
		});