/**
 * @author mrdoob / 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
 * @author bhouston / http://exocortex.com
 */

THREE.Geometry = function () {

	this.id = THREE.Math.generateUUID();

	this.name = '';

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

	this.faces = [];

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

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

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

	this.lineDistances = [];

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

	this.hasTangents = false;

	this.dynamic = true; // the intermediate typed arrays will be deleted when set to false

	// update flags

	this.verticesNeedUpdate = false;
	this.elementsNeedUpdate = false;
	this.uvsNeedUpdate = false;
	this.normalsNeedUpdate = false;
	this.tangentsNeedUpdate = false;
	this.colorsNeedUpdate = false;
	this.lineDistancesNeedUpdate = false;

	this.buffersNeedUpdate = false;

};

THREE.Geometry.prototype = {

	constructor: THREE.Geometry,

	addEventListener: THREE.EventDispatcher.prototype.addEventListener,
	hasEventListener: THREE.EventDispatcher.prototype.hasEventListener,
	removeEventListener: THREE.EventDispatcher.prototype.removeEventListener,
	dispatchEvent: THREE.EventDispatcher.prototype.dispatchEvent,

	applyMatrix: function ( matrix ) {

		var normalMatrix = new THREE.Matrix3().getNormalMatrix( matrix );

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

			var vertex = this.vertices[ i ];
			vertex.applyMatrix4( matrix );

		}

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

			var face = this.faces[ i ];
			face.normal.applyMatrix3( normalMatrix ).normalize();

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

				face.vertexNormals[ j ].applyMatrix3( normalMatrix ).normalize();

			}

			face.centroid.applyMatrix4( matrix );

		}

	},

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

			} else if ( face instanceof THREE.Face4 ) {

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

			}

		}

	},

	computeFaceNormals: function () {

		var cb = new THREE.Vector3(), ab = new THREE.Vector3();

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

			var face = this.faces[ f ];

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

			cb.subVectors( vC, vB );
			ab.subVectors( vA, vB );
			cb.cross( ab );

			cb.normalize();

			face.normal.copy( cb );

		}

	},

	computeVertexNormals: function ( areaWeighted ) {

		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 );

			}

		}

		if ( areaWeighted ) {

			// vertex normals weighted by triangle areas
			// http://www.iquilezles.org/www/articles/normals/normals.htm

			var vA, vB, vC, vD;
			var cb = new THREE.Vector3(), ab = new THREE.Vector3(),
				db = new THREE.Vector3(), dc = new THREE.Vector3(), bc = new THREE.Vector3();

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

				face = this.faces[ f ];

				if ( face instanceof THREE.Face3 ) {

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

					cb.subVectors( vC, vB );
					ab.subVectors( vA, vB );
					cb.cross( ab );

					vertices[ face.a ].add( cb );
					vertices[ face.b ].add( cb );
					vertices[ face.c ].add( cb );

				} else if ( face instanceof THREE.Face4 ) {

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

					// abd

					db.subVectors( vD, vB );
					ab.subVectors( vA, vB );
					db.cross( ab );

					vertices[ face.a ].add( db );
					vertices[ face.b ].add( db );
					vertices[ face.d ].add( db );

					// bcd

					dc.subVectors( vD, vC );
					bc.subVectors( vB, vC );
					dc.cross( bc );

					vertices[ face.b ].add( dc );
					vertices[ face.c ].add( dc );
					vertices[ face.d ].add( dc );

				}

			}

		} else {

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

				face = this.faces[ f ];

				if ( face instanceof THREE.Face3 ) {

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

				} else if ( face instanceof THREE.Face4 ) {

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

			}

		}

	},

	computeMorphNormals: function () {

		var i, il, f, fl, face;

		// save original normals
		// - create temp variables on first access
		//   otherwise just copy (for faster repeated calls)

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

			face = this.faces[ f ];

			if ( ! face.__originalFaceNormal ) {

				face.__originalFaceNormal = face.normal.clone();

			} else {

				face.__originalFaceNormal.copy( face.normal );

			}

			if ( ! face.__originalVertexNormals ) face.__originalVertexNormals = [];

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

				if ( ! face.__originalVertexNormals[ i ] ) {

					face.__originalVertexNormals[ i ] = face.vertexNormals[ i ].clone();

				} else {

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

				}

			}

		}

		// use temp geometry to compute face and vertex normals for each morph

		var tmpGeo = new THREE.Geometry();
		tmpGeo.faces = this.faces;

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

			// create on first access

			if ( ! this.morphNormals[ i ] ) {

				this.morphNormals[ i ] = {};
				this.morphNormals[ i ].faceNormals = [];
				this.morphNormals[ i ].vertexNormals = [];

				var dstNormalsFace = this.morphNormals[ i ].faceNormals;
				var dstNormalsVertex = this.morphNormals[ i ].vertexNormals;

				var faceNormal, vertexNormals;

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

					face = this.faces[ f ];

					faceNormal = new THREE.Vector3();

					if ( face instanceof THREE.Face3 ) {

						vertexNormals = { a: new THREE.Vector3(), b: new THREE.Vector3(), c: new THREE.Vector3() };

					} else {

						vertexNormals = { a: new THREE.Vector3(), b: new THREE.Vector3(), c: new THREE.Vector3(), d: new THREE.Vector3() };

					}

					dstNormalsFace.push( faceNormal );
					dstNormalsVertex.push( vertexNormals );

				}

			}

			var morphNormals = this.morphNormals[ i ];

			// set vertices to morph target

			tmpGeo.vertices = this.morphTargets[ i ].vertices;

			// compute morph normals

			tmpGeo.computeFaceNormals();
			tmpGeo.computeVertexNormals();

			// store morph normals

			var faceNormal, vertexNormals;

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

				face = this.faces[ f ];

				faceNormal = morphNormals.faceNormals[ f ];
				vertexNormals = morphNormals.vertexNormals[ f ];

				faceNormal.copy( face.normal );

				if ( face instanceof THREE.Face3 ) {

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

				} else {

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

				}

			}

		}

		// restore original normals

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

			face = this.faces[ f ];

			face.normal = face.__originalFaceNormal;
			face.vertexNormals = face.__originalVertexNormals;

		}

	},

	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 ];
			vB = context.vertices[ b ];
			vC = context.vertices[ c ];

			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.x - uvA.x;
			s2 = uvC.x - uvA.x;
			t1 = uvB.y - uvA.y;
			t2 = uvC.y - uvA.y;

			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 ].add( sdir );
			tan1[ b ].add( sdir );
			tan1[ c ].add( sdir );

			tan2[ a ].add( tdir );
			tan2[ b ].add( tdir );
			tan2[ c ].add( 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.d, 0, 1, 3 );
				handleTriangle( this, face.b, face.c, face.d, 1, 2, 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.sub( n.multiplyScalar( n.dot( t ) ) ).normalize();

				// Calculate handedness

				tmp2.crossVectors( 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;

	},

	computeLineDistances: function ( ) {

		var d = 0;
		var vertices = this.vertices;

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

			if ( i > 0 ) {

				d += vertices[ i ].distanceTo( vertices[ i - 1 ] );

			}

			this.lineDistances[ i ] = d;

		}

	},

	computeBoundingBox: function () {

		if ( this.boundingBox === null ) {

			this.boundingBox = new THREE.Box3();

		}

		this.boundingBox.setFromPoints( this.vertices );

	},

	computeBoundingSphere: function () {

		if ( this.boundingSphere === null ) {

			this.boundingSphere = new THREE.Sphere();

		}

		this.boundingSphere.setFromCenterAndPoints( this.boundingSphere.center, this.vertices );

	},

	/*
	 * 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;
		var indices, k, j, jl, u;

		// reset cache of vertices as it now will be changing.
		this.__tmpVertices = undefined;

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

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

			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 ] ];

			}

		};


		// if faces are completely degenerate after merging vertices, we
		// have to remove them from the geometry.
		var faceIndicesToRemove = [];

		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 ];

				indices = [ face.a, face.b, face.c ];

				var dupIndex = -1;

				// if any duplicate vertices are found in a Face3
				// we have to remove the face as nothing can be saved
				for ( var n = 0; n < 3; n ++ ) {
					if ( indices[ n ] == indices[ ( n + 1 ) % 3 ] ) {

						dupIndex = n;
						faceIndicesToRemove.push( i );
						break;

					}
				}

			} 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 ];

				// check dups in (a, b, c, d) and convert to -> face3

				indices = [ face.a, face.b, face.c, face.d ];

				var dupIndex = -1;

				for ( var n = 0; n < 4; n ++ ) {

					if ( indices[ n ] == indices[ ( n + 1 ) % 4 ] ) {

						// if more than one duplicated vertex is found
						// we can't generate any valid Face3's, thus
						// we need to remove this face complete.
						if ( dupIndex >= 0 ) {

							faceIndicesToRemove.push( i );

						}

						dupIndex = n;

					}
				}

				if ( dupIndex >= 0 ) {

					indices.splice( dupIndex, 1 );

					var newFace = new THREE.Face3( indices[0], indices[1], indices[2], face.normal, face.color, face.materialIndex );

					for ( j = 0, jl = this.faceVertexUvs.length; j < jl; j ++ ) {

						u = this.faceVertexUvs[ j ][ i ];

						if ( u ) {
							u.splice( dupIndex, 1 );
						}

					}

					if( face.vertexNormals && face.vertexNormals.length > 0) {

						newFace.vertexNormals = face.vertexNormals;
						newFace.vertexNormals.splice( dupIndex, 1 );

					}

					if( face.vertexColors && face.vertexColors.length > 0 ) {

						newFace.vertexColors = face.vertexColors;
						newFace.vertexColors.splice( dupIndex, 1 );
					}

					this.faces[ i ] = newFace;
				}

			}

		}

		for ( i = faceIndicesToRemove.length - 1; i >= 0; i -- ) {

			this.faces.splice( i, 1 );

			for ( j = 0, jl = this.faceVertexUvs.length; j < jl; j ++ ) {

				this.faceVertexUvs[ j ].splice( i, 1 );

			}

		}

		// Use unique set of vertices

		var diff = this.vertices.length - unique.length;
		this.vertices = unique;
		return diff;

	},

	clone: function () {

		var geometry = new THREE.Geometry();

		var vertices = this.vertices;

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

			geometry.vertices.push( vertices[ i ].clone() );

		}

		var faces = this.faces;

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

			geometry.faces.push( faces[ i ].clone() );

		}

		var uvs = this.faceVertexUvs[ 0 ];

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

			var uv = uvs[ i ], uvCopy = [];

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

				uvCopy.push( new THREE.Vector2( uv[ j ].x, uv[ j ].y ) );

			}

			geometry.faceVertexUvs[ 0 ].push( uvCopy );

		}

		return geometry;

	},

	dispose: function () {

		this.dispatchEvent( { type: 'dispose' } );

	}

};