three.js/src/core/Geometry.js

/**
 * @author mr.doob / http://mrdoob.com/
 * @author kile / http://kile.stravaganza.org/
 * @author alteredq / http://alteredqualia.com/
 * @author mikael emtinger / http://gomo.se/
 * @author zz85 / http://www.lab4games.net/zz85/blog
 */

THREE.Geometry = function () {

	this.id = THREE.GeometryCount ++;

	this.vertices = [];
	this.colors = []; // one-to-one vertex colors, used in ParticleSystem, Line and Ribbon

	this.materials = [];

	this.faces = [];

	this.faceUvs = [[]];
	this.faceVertexUvs = [[]];

	this.morphTargets = [];
	this.morphColors = [];

	this.skinWeights = [];
	this.skinIndices = [];

	this.boundingBox = null;
	this.boundingSphere = null;

	this.hasTangents = false;

	this.dynamic = false; // unless set to true the *Arrays will be deleted once sent to a buffer.

};

THREE.Geometry.prototype = {

	constructor : THREE.Geometry,

	applyMatrix: function ( matrix ) {

		var matrixRotation = new THREE.Matrix4();
		matrixRotation.extractRotation( matrix, new THREE.Vector3( 1, 1, 1 ) );

		for ( var i = 0, il = this.vertices.length; i < il; i ++ ) {

			var vertex = this.vertices[ i ];

			matrix.multiplyVector3( vertex.position );

		}

		for ( var i = 0, il = this.faces.length; i < il; i ++ ) {

			var face = this.faces[ i ];

			matrixRotation.multiplyVector3( face.normal );

			for ( var j = 0, jl = face.vertexNormals.length; j < jl; j ++ ) {

				matrixRotation.multiplyVector3( face.vertexNormals[ j ] );

			}

			matrix.multiplyVector3( face.centroid );

		}

	},

	computeCentroids: function () {

		var f, fl, face;

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];
			face.centroid.set( 0, 0, 0 );

			if ( face instanceof THREE.Face3 ) {

				face.centroid.addSelf( this.vertices[ face.a ].position );
				face.centroid.addSelf( this.vertices[ face.b ].position );
				face.centroid.addSelf( this.vertices[ face.c ].position );
				face.centroid.divideScalar( 3 );

			} else if ( face instanceof THREE.Face4 ) {

				face.centroid.addSelf( this.vertices[ face.a ].position );
				face.centroid.addSelf( this.vertices[ face.b ].position );
				face.centroid.addSelf( this.vertices[ face.c ].position );
				face.centroid.addSelf( this.vertices[ face.d ].position );
				face.centroid.divideScalar( 4 );

			}

		}

	},

	computeFaceNormals: function () {

		var n, nl, v, vl, vertex, f, fl, face, vA, vB, vC,
		cb = new THREE.Vector3(), ab = new THREE.Vector3();

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			vA = this.vertices[ face.a ];
			vB = this.vertices[ face.b ];
			vC = this.vertices[ face.c ];

			cb.sub( vC.position, vB.position );
			ab.sub( vA.position, vB.position );
			cb.crossSelf( ab );

			if ( !cb.isZero() ) {

				cb.normalize();

			}

			face.normal.copy( cb );

		}

	},

	computeVertexNormals: function () {

		var v, vl, f, fl, face, vertices;

		// create internal buffers for reuse when calling this method repeatedly
		// (otherwise memory allocation / deallocation every frame is big resource hog)

		if ( this.__tmpVertices === undefined ) {

			this.__tmpVertices = new Array( this.vertices.length );
			vertices = this.__tmpVertices;

			for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

				vertices[ v ] = new THREE.Vector3();

			}

			for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

				face = this.faces[ f ];

				if ( face instanceof THREE.Face3 ) {

					face.vertexNormals = [ new THREE.Vector3(), new THREE.Vector3(), new THREE.Vector3() ];

				} else if ( face instanceof THREE.Face4 ) {

					face.vertexNormals = [ new THREE.Vector3(), new THREE.Vector3(), new THREE.Vector3(), new THREE.Vector3() ];

				}

			}

		} else {

			vertices = this.__tmpVertices;

			for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

				vertices[ v ].set( 0, 0, 0 );

			}

		}

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			if ( face instanceof THREE.Face3 ) {

				vertices[ face.a ].addSelf( face.normal );
				vertices[ face.b ].addSelf( face.normal );
				vertices[ face.c ].addSelf( face.normal );

			} else if ( face instanceof THREE.Face4 ) {

				vertices[ face.a ].addSelf( face.normal );
				vertices[ face.b ].addSelf( face.normal );
				vertices[ face.c ].addSelf( face.normal );
				vertices[ face.d ].addSelf( face.normal );

			}

		}

		for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			vertices[ v ].normalize();

		}

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			if ( face instanceof THREE.Face3 ) {

				face.vertexNormals[ 0 ].copy( vertices[ face.a ] );
				face.vertexNormals[ 1 ].copy( vertices[ face.b ] );
				face.vertexNormals[ 2 ].copy( vertices[ face.c ] );

			} else if ( face instanceof THREE.Face4 ) {

				face.vertexNormals[ 0 ].copy( vertices[ face.a ] );
				face.vertexNormals[ 1 ].copy( vertices[ face.b ] );
				face.vertexNormals[ 2 ].copy( vertices[ face.c ] );
				face.vertexNormals[ 3 ].copy( vertices[ face.d ] );

			}

		}

	},

	computeTangents: function () {

		// based on http://www.terathon.com/code/tangent.html
		// tangents go to vertices

		var f, fl, v, vl, i, il, vertexIndex,
			face, uv, vA, vB, vC, uvA, uvB, uvC,
			x1, x2, y1, y2, z1, z2,
			s1, s2, t1, t2, r, t, test,
			tan1 = [], tan2 = [],
			sdir = new THREE.Vector3(), tdir = new THREE.Vector3(),
			tmp = new THREE.Vector3(), tmp2 = new THREE.Vector3(),
			n = new THREE.Vector3(), w;

		for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			tan1[ v ] = new THREE.Vector3();
			tan2[ v ] = new THREE.Vector3();

		}

		function handleTriangle( context, a, b, c, ua, ub, uc ) {

			vA = context.vertices[ a ].position;
			vB = context.vertices[ b ].position;
			vC = context.vertices[ c ].position;

			uvA = uv[ ua ];
			uvB = uv[ ub ];
			uvC = uv[ uc ];

			x1 = vB.x - vA.x;
			x2 = vC.x - vA.x;
			y1 = vB.y - vA.y;
			y2 = vC.y - vA.y;
			z1 = vB.z - vA.z;
			z2 = vC.z - vA.z;

			s1 = uvB.u - uvA.u;
			s2 = uvC.u - uvA.u;
			t1 = uvB.v - uvA.v;
			t2 = uvC.v - uvA.v;

			r = 1.0 / ( s1 * t2 - s2 * t1 );
			sdir.set( ( t2 * x1 - t1 * x2 ) * r,
					  ( t2 * y1 - t1 * y2 ) * r,
					  ( t2 * z1 - t1 * z2 ) * r );
			tdir.set( ( s1 * x2 - s2 * x1 ) * r,
					  ( s1 * y2 - s2 * y1 ) * r,
					  ( s1 * z2 - s2 * z1 ) * r );

			tan1[ a ].addSelf( sdir );
			tan1[ b ].addSelf( sdir );
			tan1[ c ].addSelf( sdir );

			tan2[ a ].addSelf( tdir );
			tan2[ b ].addSelf( tdir );
			tan2[ c ].addSelf( tdir );

		}

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];
			uv = this.faceVertexUvs[ 0 ][ f ]; // use UV layer 0 for tangents

			if ( face instanceof THREE.Face3 ) {

				handleTriangle( this, face.a, face.b, face.c, 0, 1, 2 );

			} else if ( face instanceof THREE.Face4 ) {

				handleTriangle( this, face.a, face.b, face.c, 0, 1, 2 );
				handleTriangle( this, face.a, face.b, face.d, 0, 1, 3 );

			}

		}

		var faceIndex = [ 'a', 'b', 'c', 'd' ];

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			for ( i = 0; i < face.vertexNormals.length; i++ ) {

				n.copy( face.vertexNormals[ i ] );

				vertexIndex = face[ faceIndex[ i ] ];

				t = tan1[ vertexIndex ];

				// Gram-Schmidt orthogonalize

				tmp.copy( t );
				tmp.subSelf( n.multiplyScalar( n.dot( t ) ) ).normalize();

				// Calculate handedness

				tmp2.cross( face.vertexNormals[ i ], t );
				test = tmp2.dot( tan2[ vertexIndex ] );
				w = (test < 0.0) ? -1.0 : 1.0;

				face.vertexTangents[ i ] = new THREE.Vector4( tmp.x, tmp.y, tmp.z, w );

			}

		}

		this.hasTangents = true;

	},

	computeBoundingBox: function () {

		var vertex;

		if ( this.vertices.length > 0 ) {

			this.boundingBox = { 'x': [ this.vertices[ 0 ].position.x, this.vertices[ 0 ].position.x ],
			'y': [ this.vertices[ 0 ].position.y, this.vertices[ 0 ].position.y ],
			'z': [ this.vertices[ 0 ].position.z, this.vertices[ 0 ].position.z ] };

			for ( var v = 1, vl = this.vertices.length; v < vl; v ++ ) {

				vertex = this.vertices[ v ];

				if ( vertex.position.x < this.boundingBox.x[ 0 ] ) {

					this.boundingBox.x[ 0 ] = vertex.position.x;

				} else if ( vertex.position.x > this.boundingBox.x[ 1 ] ) {

					this.boundingBox.x[ 1 ] = vertex.position.x;

				}

				if ( vertex.position.y < this.boundingBox.y[ 0 ] ) {

					this.boundingBox.y[ 0 ] = vertex.position.y;

				} else if ( vertex.position.y > this.boundingBox.y[ 1 ] ) {

					this.boundingBox.y[ 1 ] = vertex.position.y;

				}

				if ( vertex.position.z < this.boundingBox.z[ 0 ] ) {

					this.boundingBox.z[ 0 ] = vertex.position.z;

				} else if ( vertex.position.z > this.boundingBox.z[ 1 ] ) {

					this.boundingBox.z[ 1 ] = vertex.position.z;

				}

			}

		}

	},

	computeBoundingSphere: function () {

		// var radius = this.boundingSphere === null ? 0 : this.boundingSphere.radius;

		var radius = 0;

		for ( var v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			radius = Math.max( radius, this.vertices[ v ].position.length() );

		}

		this.boundingSphere = { radius: radius };

	},

	/*
	 * Checks for duplicate vertices with hashmap.
	 * Duplicated vertices are removed
	 * and faces' vertices are updated.
	 */

	mergeVertices: function() {

		var verticesMap = {}; // Hashmap for looking up vertice by position coordinates (and making sure they are unique)
		var unique = [], changes = [];

		var v, key;
		var precisionPoints = 4; // number of decimal points, eg. 4 for epsilon of 0.0001
		var precision = Math.pow( 10, precisionPoints );
		var i,il, face;

		for ( i = 0, il = this.vertices.length; i < il; i ++ ) {

			v = this.vertices[ i ].position;
			key = [ Math.round( v.x * precision ), Math.round( v.y * precision ), Math.round( v.z * precision ) ].join( '_' );

			if ( verticesMap[ key ] === undefined ) {

				verticesMap[ key ] = i;
				unique.push( this.vertices[ i ] );
				changes[ i ] = unique.length - 1;

			} else {

				//console.log('Duplicate vertex found. ', i, ' could be using ', verticesMap[key]);
				changes[ i ] = changes[ verticesMap[ key ] ];

			}

		};


		// Start to patch face indices

		for( i = 0, il = this.faces.length; i < il; i ++ ) {

			face = this.faces[ i ];

			if ( face instanceof THREE.Face3 ) {

				face.a = changes[ face.a ];
				face.b = changes[ face.b ];
				face.c = changes[ face.c ];

			} else if ( face instanceof THREE.Face4 ) {

				face.a = changes[ face.a ];
				face.b = changes[ face.b ];
				face.c = changes[ face.c ];
				face.d = changes[ face.d ];

			}

		}

		// Use unique set of vertices

		this.vertices = unique;

	}

};

THREE.GeometryCount = 0;