three.js/examples/js/loaders/VTKLoader.js

/**
 * @author Sebastien Valette [email protected]
 */

THREE.VTKLoader = function () {};

THREE.VTKLoader.prototype = new THREE.Loader();
THREE.VTKLoader.prototype.constructor = THREE.VTKLoader;

THREE.VTKLoader.prototype.load = function ( url, callback ) {

	var that = this;
	var xhr = new XMLHttpRequest();

	xhr.onreadystatechange = function () {

		if ( xhr.readyState == 4 ) {

			if ( xhr.status == 200 || xhr.status == 0 ) {

				callback( that.parse( xhr.responseText ) );

			} else {

				console.error( 'THREE.VTKLoader: Couldn\'t load ' + url + ' (' + xhr.status + ')' );

			}

		}

	};

	xhr.open( "GET", url, true );
	xhr.send( null );

};

THREE.VTKLoader.prototype.parse = function ( data ) {

	var geometry = new THREE.Geometry();
	var lines = data.split("\n");

	function v( x, y, z ) {

		geometry.vertices.push( new THREE.Vector3( x, y, z ) );

	}

	function f3( a, b, c ) {

		geometry.faces.push( new THREE.Face3( a, b, c ) );

	}

	var lineIndex = 0;

	var line = lines[ 0 ].split( ' ' );
	var lineLength = line.length;
	var columnIndex = -1;

	function readNextString() {

		while ( 1 ) {

			var nextWord = line[ columnIndex ];
			columnIndex ++;

			if ( columnIndex == lineLength ) {

				lineIndex ++;
				columnIndex = 0;

				if ( lineIndex > lines.length ) {

					return '';

				}

				line = lines[ lineIndex ].split( ' ' );
				lineLength = line.length;

			}

			if ( nextWord != null ) {

				if ( nextWord.length > 0 ) {

					return nextWord;

				}

			}

		}

	}

	// read point data
	var found = false;
	while ( !found ) {

		var readString = readNextString();

		switch ( readString.toUpperCase() ) {

			case 'POINTS':
				found = true;
				break;

			case '':
				alert ( 'error while reading ' + url + ' : \n' );
				return;

		}

	}

	var newIndex;
	var new2old;

	var numberOfPoints = parseInt( readNextString() );

	if ( numberOfPoints > 5000000 ) {

		alert ( 'mesh is too big : ' + numberOfPoints + ' vertices' );
		return;

	}

	var coord = [ 0, 0, 0 ];
	var index2 = 0;

	var number;
	var coordIndex;

	for ( var j = 0; j != numberOfPoints; j ++ ) {

		for ( coordIndex = 0; coordIndex < 3; coordIndex ++ ) {

			do {

				number = parseFloat( line[ columnIndex ] );

				columnIndex ++;

				if ( columnIndex == lineLength ) {

					lineIndex ++;
					columnIndex = 0;

					if ( lineIndex > lines.length ) {

						alert ( 'error while reading ' + url + ' : \n' );
						return;
					}

					line = lines[ lineIndex ].split( ' ' );
					lineLength = line.length;
				}
			} while ( isNaN( number ) )

			coord[ coordIndex ] = number;
		}

		v( coord[ 0 ], coord[ 1 ], coord[ 2 ] );

	}

	found = false;

	while ( !found ) {

		var readString = readNextString();

		switch ( readString ) {

			case 'POLYGONS':
				found = true;
				break;

			case '':
				alert ( 'error while reading ' + url + ' : \n' );
				return;

		}

	}

	var numberOfPolygons = parseInt( readNextString() );
	var numberOfpolygonElements = parseInt( readNextString() );

	index2 = 0;
	var connectivity = [];

	for ( var p = 0; p != numberOfpolygonElements; p ++ ) {

		do {

			number = parseInt( line[ columnIndex ] );

			columnIndex ++;

			if ( columnIndex == lineLength ) {

				lineIndex ++;
				columnIndex = 0;

				if ( lineIndex > lines.length ) {

					alert ( 'error while reading ' + url + ' : \n' );
					return;

				}

				line = lines[ lineIndex ].split( ' ' );
				lineLength = line.length;
			}
		} while ( isNaN( number ) )

		connectivity[ index2 ] = number;
		index2 ++;

		if ( index2 == connectivity[ 0 ] + 1 ) {

			var triangle = [ 0, 0, 0 ];
			index2 = 0;

			var numberOfTrianglesInCell = connectivity[ 0 ] - 2;
			var vertex1 = triangle[ 0 ] = connectivity[ 1 ];

			for ( var i = 0; i < numberOfTrianglesInCell; i ++ ) {

				var vertex2 = connectivity[ i + 2 ];
				var vertex3 = triangle[ 2 ] = connectivity[ i + 3 ];

				f3( vertex1, vertex2, vertex3 );

			}

		}

	}

	geometry.computeCentroids();
	geometry.computeFaceNormals();
	geometry.computeVertexNormals();
	geometry.computeBoundingSphere();

	return geometry;

}