polygonal-pathfinding/index.html at master · makc/polygonal-pathfinding · GitHub

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<html>
<head>
	<meta charset="utf8" />
	<title>path finding with 3js</title>
	<style>* { margin: 0; overflow: hidden; background-color: black; }</style>
</head>
<body>
	<script src="https://rawcdn.githack.com/mrdoob/three.js/e0a31ea77c0242ae29ef6e951fa588216e1d247f/build/three.min.js"></script>
	<script src="https://rawcdn.githack.com/mrdoob/three.js/e0a31ea77c0242ae29ef6e951fa588216e1d247f/examples/js/controls/OrbitControls.js"></script>
	<script src="pathfinding.js"></script>
	<script>

var Pathfinder = function( geometry ) {

	// assume non-interleaved positions for speed

	var positions = geometry.getAttribute( "position" ).array;
	var indices = geometry.getIndex().array;

	var astar = new de.polygonal.ai.pathfinding.AStar();
	var graph = new de.polygonal.ds.Graph();

	var nodes = {};
	for( var i = 0, j = 0; i < positions.length; i += 3, j++ ) {
		var wp = new de.polygonal.ai.pathfinding.AStarWaypoint();
		wp.x = positions[ i ];
		wp.y = positions[ i + 1 ];
		wp.z = positions[ i + 2 ];
		wp.node = graph.createNode( wp ); graph.addNode( wp.node );
		nodes[ j ] = wp;
	}

	var edges = {};
	for( var i = 0; i < indices.length; i += 3 ) {
		for( var j = 0; j < 3; j++ ) {
			var k = ( j + 1 ) % 3;
			var a = indices[ i + j ];
			var b = indices[ i + k ];
			var c = Math.min( a, b ) + "-" + Math.max( a, b );
			if( edges[ c ] === undefined ) {
				edges[ c ] = true;

				// assume equal cost arcs for speed

				graph.addMutualArc( nodes[ a ].node, nodes[ b ].node );
			}
		}
	}

	edges = undefined;

	this.findPath = function( a, b ) {
		var path = [];
		if( astar.find( graph, nodes[ a ], nodes[ b ], path ) ) {
			return path;
		}
	};
};


var loader = new THREE.FileLoader();
loader.load( "terrain.obj", function( text ) {
	console.time( "parsing obj file" );

	var positions = [], indices = [];
	for( var line of text.split( "\n" ) ) {
		var words = line.split( " " );
		switch( line.charAt( 0 ) ) {
			case "v":
				positions.push( parseFloat( words[1] ), parseFloat( words[2] ), parseFloat( words[3] ) );
				break;
			case "f":
				indices.push( parseInt( words[1] ) -1, parseInt( words[2] ) -1, parseInt( words[3] ) -1 );
				break;
		}
	}

	var geometry = new THREE.BufferGeometry();
	geometry.setAttribute( "position", new THREE.Float32BufferAttribute( positions, 3 ) );
	geometry.setIndex( new THREE.Int16BufferAttribute( indices, 1 ) );

	console.timeEnd( "parsing obj file" );


	console.time( "setting the path finder up" );

	var pathfinder = new Pathfinder( geometry );

	console.timeEnd( "setting the path finder up" );


	var scene = new THREE.Scene();
	var camera = new THREE.PerspectiveCamera( 42, 1, 2, 200 );

	camera.position.set( 30, 40, 70 );
	camera.lookAt( scene.position );

	var renderer = new THREE.WebGLRenderer( { antialias: true } );
	document.body.appendChild( renderer.domElement );

	var render = function() {
		renderer.render( scene, camera );
	};

	var resize = function() {
		var w = innerWidth, h = innerHeight;
		camera.aspect = w / h; camera.updateProjectionMatrix();
		renderer.setSize( w, h );
		render();
	};
	addEventListener( "resize", resize );

	scene.add( new THREE.Mesh( geometry, new THREE.MeshBasicMaterial( { color: 0x333333, wireframe: true } ) ) );
	resize();

	var controls = new THREE.OrbitControls( camera, renderer.domElement );
	controls.minDistance =  50;
	controls.maxDistance = 150;
	controls.addEventListener( "change", render );

	// demo

	var line = new THREE.Line( new THREE.BufferGeometry(), new THREE.LineBasicMaterial( {
		color: 0xff0000, depthTest: false, transparent: true
	} ) );
	scene.add( line );

	setInterval( function() {
		var n = positions.length / 3;
		var a = Math.floor( n * Math.random() ) % n;
		var b = ( a + Math.floor( n / 2 ) ) % n;

		console.time( "finding the path from " + a + " to " + b );

		var path = pathfinder.findPath( a, b );

		console.timeEnd( "finding the path from " + a + " to " + b );

		if( path ) {
			line.geometry.dispose();
			line.geometry = new THREE.BufferGeometry().setFromPoints( path );

			requestAnimationFrame( render );
		}

	}, 1234 );
});

</script>
</body>
</html>