/**
 * @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
 */

THREE.Geometry = function () {

	THREE.GeometryLibrary.push( this );

	this.id = THREE.GeometryIdCount ++;

	this.name = '';

	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.morphNormals = [];

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

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

	this.hasTangents = false;

	this.dynamic = true; // the intermediate typearrays 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;

};

THREE.Geometry.prototype = {

	constructor : THREE.Geometry,

	applyMatrix: function ( matrix ) {

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

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

			var vertex = this.vertices[ i ];

			matrix.multiplyVector3( vertex );

		}

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

			} else if ( face instanceof THREE.Face4 ) {

				face.centroid.addSelf( this.vertices[ face.a ] );
				face.centroid.addSelf( this.vertices[ face.b ] );
				face.centroid.addSelf( this.vertices[ face.c ] );
				face.centroid.addSelf( this.vertices[ face.d ] );
				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, vB );
			ab.sub( vA, vB );
			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 ] );

			}

		}

	},

	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.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.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.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 () {

		if ( ! this.boundingBox ) {

			this.boundingBox = { min: new THREE.Vector3(), max: new THREE.Vector3() };

		}

		if ( this.vertices.length > 0 ) {

			var position, firstPosition = this.vertices[ 0 ];

			this.boundingBox.min.copy( firstPosition );
			this.boundingBox.max.copy( firstPosition );

			var min = this.boundingBox.min,
				max = this.boundingBox.max;

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

				position = this.vertices[ v ];

				if ( position.x < min.x ) {

					min.x = position.x;

				} else if ( position.x > max.x ) {

					max.x = position.x;

				}

				if ( position.y < min.y ) {

					min.y = position.y;

				} else if ( position.y > max.y ) {

					max.y = position.y;

				}

				if ( position.z < min.z ) {

					min.z = position.z;

				} else if ( position.z > max.z ) {

					max.z = position.z;

				}

			}

		} else {

			this.boundingBox.min.set( 0, 0, 0 );
			this.boundingBox.max.set( 0, 0, 0 );

		}

	},

	computeBoundingSphere: function () {

		var maxRadiusSq = 0;

		if ( this.boundingSphere === null ) this.boundingSphere = { radius: 0 };

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

			var radiusSq = this.vertices[ i ].lengthSq();
			if ( radiusSq > maxRadiusSq ) maxRadiusSq = radiusSq;

		}

		this.boundingSphere.radius = Math.sqrt( maxRadiusSq );

	},

	/*
	 * 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 abcd = 'abcd', o, k, j, jl, u;

		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 ) ].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 ];

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

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

				for ( k = 3; k > 0; k -- ) {

					if ( o.indexOf( face[ abcd[ k ] ] ) !== k ) {

						// console.log('faces', face.a, face.b, face.c, face.d, 'dup at', k);

						o.splice( k, 1 );

						this.faces[ i ] = new THREE.Face3( o[0], o[1], o[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( k, 1 );

						}

						this.faces[ i ].vertexColors = face.vertexColors;

						break;
					}

				}

			}

		}

		// Use unique set of vertices

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

	},

	clone: function () {

		// TODO

	},

	deallocate: function () {

		var index = THREE.GeometryLibrary.indexOf( this );
		if ( index !== -1 ) THREE.GeometryLibrary.splice( index, 1 );

	}

};

THREE.GeometryIdCount = 0;
THREE.GeometryLibrary = [];
