/**
 * @author mrdoob / http://mrdoob.com/
 * @author supereggbert / http://www.paulbrunt.co.uk/
 * @author julianwa / https://github.com/julianwa
 */

THREE.RenderableObject = function () {

    this.id = 0;

    this.object = null;
    this.z = 0;

};

//

THREE.RenderableFace = function () {

    this.id = 0;

    this.v1 = new THREE.RenderableVertex();
    this.v2 = new THREE.RenderableVertex();
    this.v3 = new THREE.RenderableVertex();

    this.normalModel = new THREE.Vector3();

    this.vertexNormalsModel = [ new THREE.Vector3(), new THREE.Vector3(), new THREE.Vector3() ];
    this.vertexNormalsLength = 0;

    this.color = new THREE.Color();
    this.material = null;
    this.uvs = [ new THREE.Vector2(), new THREE.Vector2(), new THREE.Vector2() ];

    this.z = 0;

};

//

THREE.RenderableVertex = function () {

    this.position = new THREE.Vector3();
    this.positionWorld = new THREE.Vector3();
    this.positionScreen = new THREE.Vector4();

    this.visible = true;

};

THREE.RenderableVertex.prototype.copy = function ( vertex ) {

    this.positionWorld.copy( vertex.positionWorld );
    this.positionScreen.copy( vertex.positionScreen );

};

//

THREE.RenderableLine = function () {

    this.id = 0;

    this.v1 = new THREE.RenderableVertex();
    this.v2 = new THREE.RenderableVertex();

    this.vertexColors = [ new THREE.Color(), new THREE.Color() ];
    this.material = null;

    this.z = 0;

};

//

THREE.RenderableSprite = function () {

    this.id = 0;

    this.object = null;

    this.x = 0;
    this.y = 0;
    this.z = 0;

    this.rotation = 0;
    this.scale = new THREE.Vector2();

    this.material = null;

};

//

THREE.Projector = function () {

    var _object, _objectCount, _objectPool = [], _objectPoolLength = 0,
        _vertex, _vertexCount, _vertexPool = [], _vertexPoolLength = 0,
        _face, _faceCount, _facePool = [], _facePoolLength = 0,
        _line, _lineCount, _linePool = [], _linePoolLength = 0,
        _sprite, _spriteCount, _spritePool = [], _spritePoolLength = 0,

        _renderData = { objects: [], lights: [], elements: [] },

        _vA = new THREE.Vector3(),
        _vB = new THREE.Vector3(),
        _vC = new THREE.Vector3(),

        _vector3 = new THREE.Vector3(),
        _vector4 = new THREE.Vector4(),

        _clipBox = new THREE.Box3( new THREE.Vector3( - 1, - 1, - 1 ), new THREE.Vector3( 1, 1, 1 ) ),
        _boundingBox = new THREE.Box3(),
        _points3 = new Array( 3 ),
        _points4 = new Array( 4 ),

        _viewMatrix = new THREE.Matrix4(),
        _viewProjectionMatrix = new THREE.Matrix4(),

        _modelMatrix,
        _modelViewProjectionMatrix = new THREE.Matrix4(),

        _normalMatrix = new THREE.Matrix3(),

        _frustum = new THREE.Frustum(),

        _clippedVertex1PositionScreen = new THREE.Vector4(),
        _clippedVertex2PositionScreen = new THREE.Vector4();

    //

    this.projectVector = function ( vector, camera ) {

        console.warn( 'THREE.Projector: .projectVector() is now vector.project().' );
        vector.project( camera );

    };

    this.unprojectVector = function ( vector, camera ) {

        console.warn( 'THREE.Projector: .unprojectVector() is now vector.unproject().' );
        vector.unproject( camera );

    };

    this.pickingRay = function ( vector, camera ) {

        console.error( 'THREE.Projector: .pickingRay() is now raycaster.setFromCamera().' );

    };

    //

    var RenderList = function () {

        var normals = [];
        var uvs = [];

        var object = null;
        var material = null;

        var normalMatrix = new THREE.Matrix3();

        var setObject = function ( value ) {

            object = value;
            material = object.material;

            normalMatrix.getNormalMatrix( object.matrixWorld );

            normals.length = 0;
            uvs.length = 0;

        };

        var projectVertex = function ( vertex ) {

            var position = vertex.position;
            var positionWorld = vertex.positionWorld;
            var positionScreen = vertex.positionScreen;

            positionWorld.copy( position ).applyMatrix4( _modelMatrix );
            positionScreen.copy( positionWorld ).applyMatrix4( _viewProjectionMatrix );

            var invW = 1 / positionScreen.w;

            positionScreen.x *= invW;
            positionScreen.y *= invW;
            positionScreen.z *= invW;

            vertex.visible = positionScreen.x >= - 1 && positionScreen.x <= 1 &&
                positionScreen.y >= - 1 && positionScreen.y <= 1 &&
                positionScreen.z >= - 1 && positionScreen.z <= 1;

        };

        var pushVertex = function ( x, y, z ) {

            _vertex = getNextVertexInPool();
            _vertex.position.set( x, y, z );

            projectVertex( _vertex );

        };

        var pushNormal = function ( x, y, z ) {

            normals.push( x, y, z );

        };

        var pushUv = function ( x, y ) {

            uvs.push( x, y );

        };

        var checkTriangleVisibility = function ( v1, v2, v3 ) {

            if ( v1.visible === true || v2.visible === true || v3.visible === true ) return true;

            _points3[ 0 ] = v1.positionScreen;
            _points3[ 1 ] = v2.positionScreen;
            _points3[ 2 ] = v3.positionScreen;

            return _clipBox.isIntersectionBox( _boundingBox.setFromPoints( _points3 ) );

        };

        var checkBackfaceCulling = function ( v1, v2, v3 ) {

            return ( ( v3.positionScreen.x - v1.positionScreen.x ) *
                ( v2.positionScreen.y - v1.positionScreen.y ) -
                ( v3.positionScreen.y - v1.positionScreen.y ) *
                ( v2.positionScreen.x - v1.positionScreen.x ) ) < 0;

        };

        var pushLine = function ( a, b ) {

            var v1 = _vertexPool[ a ];
            var v2 = _vertexPool[ b ];

            _line = getNextLineInPool();

            _line.id = object.id;
            _line.v1.copy( v1 );
            _line.v2.copy( v2 );
            _line.z = ( v1.positionScreen.z + v2.positionScreen.z ) / 2;

            _line.material = object.material;

            _renderData.elements.push( _line );

        };

        var pushTriangle = function ( a, b, c ) {

            var v1 = _vertexPool[ a ];
            var v2 = _vertexPool[ b ];
            var v3 = _vertexPool[ c ];

            if ( checkTriangleVisibility( v1, v2, v3 ) === false ) return;

            if ( material.side === THREE.DoubleSide || checkBackfaceCulling( v1, v2, v3 ) === true ) {

                _face = getNextFaceInPool();

                _face.id = object.id;
                _face.v1.copy( v1 );
                _face.v2.copy( v2 );
                _face.v3.copy( v3 );
                _face.z = ( v1.positionScreen.z + v2.positionScreen.z + v3.positionScreen.z ) / 3;

                for ( var i = 0; i < 3; i ++ ) {

                    var offset = arguments[ i ] * 3;
                    var normal = _face.vertexNormalsModel[ i ];

                    normal.set( normals[ offset ], normals[ offset + 1 ], normals[ offset + 2 ] );
                    normal.applyMatrix3( normalMatrix ).normalize();

                    var offset2 = arguments[ i ] * 2;

                    var uv = _face.uvs[ i ];
                    uv.set( uvs[ offset2 ], uvs[ offset2 + 1 ] );

                }

                _face.vertexNormalsLength = 3;

                _face.material = object.material;

                _renderData.elements.push( _face );

            }

        };

        return {
            setObject: setObject,
            projectVertex: projectVertex,
            checkTriangleVisibility: checkTriangleVisibility,
            checkBackfaceCulling: checkBackfaceCulling,
            pushVertex: pushVertex,
            pushNormal: pushNormal,
            pushUv: pushUv,
            pushLine: pushLine,
            pushTriangle: pushTriangle
        }

    };

    var renderList = new RenderList();

    this.projectScene = function ( scene, camera, sortObjects, sortElements ) {

        _faceCount = 0;
        _lineCount = 0;
        _spriteCount = 0;

        _renderData.elements.length = 0;

        if ( scene.autoUpdate === true ) scene.updateMatrixWorld();
        if ( camera.parent === undefined ) camera.updateMatrixWorld();

        _viewMatrix.copy( camera.matrixWorldInverse.getInverse( camera.matrixWorld ) );
        _viewProjectionMatrix.multiplyMatrices( camera.projectionMatrix, _viewMatrix );

        _frustum.setFromMatrix( _viewProjectionMatrix );

        //

        _objectCount = 0;

        _renderData.objects.length = 0;
        _renderData.lights.length = 0;

        scene.traverseVisible( function ( object ) {

            if ( object instanceof THREE.Light ) {

                _renderData.lights.push( object );

            } else if ( object instanceof THREE.Mesh || object instanceof THREE.Line || object instanceof THREE.Sprite ) {

                if ( object.material.visible === false ) return;

                if ( object.frustumCulled === false || _frustum.intersectsObject( object ) === true ) {

                    _object = getNextObjectInPool();
                    _object.id = object.id;
                    _object.object = object;

                    _vector3.setFromMatrixPosition( object.matrixWorld );
                    _vector3.applyProjection( _viewProjectionMatrix );
                    _object.z = _vector3.z;

                    _renderData.objects.push( _object );

                }

            }

        } );

        if ( sortObjects === true ) {

            _renderData.objects.sort( painterSort );

        }

        //

        for ( var o = 0, ol = _renderData.objects.length; o < ol; o ++ ) {

            var object = _renderData.objects[ o ].object;
            var geometry = object.geometry;

            renderList.setObject( object );

            _modelMatrix = object.matrixWorld;

            _vertexCount = 0;

            if ( object instanceof THREE.Mesh ) {

                if ( geometry instanceof THREE.BufferGeometry ) {

                    var attributes = geometry.attributes;
                    var offsets = geometry.offsets;

                    if ( attributes.position === undefined ) continue;

                    var positions = attributes.position.array;

                    for ( var i = 0, l = positions.length; i < l; i += 3 ) {

                        renderList.pushVertex( positions[ i ], positions[ i + 1 ], positions[ i + 2 ] );

                    }

                    if ( attributes.normal !== undefined ) {

                        var normals = attributes.normal.array;

                        for ( var i = 0, l = normals.length; i < l; i += 3 ) {

                            renderList.pushNormal( normals[ i ], normals[ i + 1 ], normals[ i + 2 ] );

                        }

                    }

                    if ( attributes.uv !== undefined ) {

                        var uvs = attributes.uv.array;

                        for ( var i = 0, l = uvs.length; i < l; i += 2 ) {

                            renderList.pushUv( uvs[ i ], uvs[ i + 1 ] );

                        }

                    }

                    if ( attributes.index !== undefined ) {

                        var indices = attributes.index.array;

                        if ( offsets.length > 0 ) {

                            for ( var o = 0; o < offsets.length; o ++ ) {

                                var offset = offsets[ o ];
                                var index = offset.index;

                                for ( var i = offset.start, l = offset.start + offset.count; i < l; i += 3 ) {

                                    renderList.pushTriangle( indices[ i ] + index, indices[ i + 1 ] + index, indices[ i + 2 ] + index );

                                }

                            }

                        } else {

                            for ( var i = 0, l = indices.length; i < l; i += 3 ) {

                                renderList.pushTriangle( indices[ i ], indices[ i + 1 ], indices[ i + 2 ] );

                            }

                        }

                    } else {

                        for ( var i = 0, l = positions.length / 3; i < l; i += 3 ) {

                            renderList.pushTriangle( i, i + 1, i + 2 );

                        }

                    }

                } else if ( geometry instanceof THREE.Geometry ) {

                    var vertices = geometry.vertices;
                    var faces = geometry.faces;
                    var faceVertexUvs = geometry.faceVertexUvs[ 0 ];

                    _normalMatrix.getNormalMatrix( _modelMatrix );

                    var isFaceMaterial = object.material instanceof THREE.MeshFaceMaterial;
                    var objectMaterials = isFaceMaterial === true ? object.material : null;

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

                        var vertex = vertices[ v ];
                        renderList.pushVertex( vertex.x, vertex.y, vertex.z );

                    }

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

                        var face = faces[ f ];

                        var material = isFaceMaterial === true
                            ? objectMaterials.materials[ face.materialIndex ]
                            : object.material;

                        if ( material === undefined ) continue;

                        var side = material.side;

                        var v1 = _vertexPool[ face.a ];
                        var v2 = _vertexPool[ face.b ];
                        var v3 = _vertexPool[ face.c ];

                        if ( material.morphTargets === true ) {

                            var morphTargets = geometry.morphTargets;
                            var morphInfluences = object.morphTargetInfluences;

                            var v1p = v1.position;
                            var v2p = v2.position;
                            var v3p = v3.position;

                            _vA.set( 0, 0, 0 );
                            _vB.set( 0, 0, 0 );
                            _vC.set( 0, 0, 0 );

                            for ( var t = 0, tl = morphTargets.length; t < tl; t ++ ) {

                                var influence = morphInfluences[ t ];

                                if ( influence === 0 ) continue;

                                var targets = morphTargets[ t ].vertices;

                                _vA.x += ( targets[ face.a ].x - v1p.x ) * influence;
                                _vA.y += ( targets[ face.a ].y - v1p.y ) * influence;
                                _vA.z += ( targets[ face.a ].z - v1p.z ) * influence;

                                _vB.x += ( targets[ face.b ].x - v2p.x ) * influence;
                                _vB.y += ( targets[ face.b ].y - v2p.y ) * influence;
                                _vB.z += ( targets[ face.b ].z - v2p.z ) * influence;

                                _vC.x += ( targets[ face.c ].x - v3p.x ) * influence;
                                _vC.y += ( targets[ face.c ].y - v3p.y ) * influence;
                                _vC.z += ( targets[ face.c ].z - v3p.z ) * influence;

                            }

                            v1.position.add( _vA );
                            v2.position.add( _vB );
                            v3.position.add( _vC );

                            renderList.projectVertex( v1 );
                            renderList.projectVertex( v2 );
                            renderList.projectVertex( v3 );

                        }

                        if ( renderList.checkTriangleVisibility( v1, v2, v3 ) === false ) continue;

                        var visible = renderList.checkBackfaceCulling( v1, v2, v3 );

                        if ( side !== THREE.DoubleSide ) {
                            if ( side === THREE.FrontSide && visible === false ) continue;
                            if ( side === THREE.BackSide && visible === true ) continue;
                        }

                        _face = getNextFaceInPool();

                        _face.id = object.id;
                        _face.v1.copy( v1 );
                        _face.v2.copy( v2 );
                        _face.v3.copy( v3 );

                        _face.normalModel.copy( face.normal );

                        if ( visible === false && ( side === THREE.BackSide || side === THREE.DoubleSide ) ) {

                            _face.normalModel.negate();

                        }

                        _face.normalModel.applyMatrix3( _normalMatrix ).normalize();

                        var faceVertexNormals = face.vertexNormals;

                        for ( var n = 0, nl = Math.min( faceVertexNormals.length, 3 ); n < nl; n ++ ) {

                            var normalModel = _face.vertexNormalsModel[ n ];
                            normalModel.copy( faceVertexNormals[ n ] );

                            if ( visible === false && ( side === THREE.BackSide || side === THREE.DoubleSide ) ) {

                                normalModel.negate();

                            }

                            normalModel.applyMatrix3( _normalMatrix ).normalize();

                        }

                        _face.vertexNormalsLength = faceVertexNormals.length;

                        var vertexUvs = faceVertexUvs[ f ];

                        if ( vertexUvs !== undefined ) {

                            for ( var u = 0; u < 3; u ++ ) {

                                _face.uvs[ u ].copy( vertexUvs[ u ] );

                            }

                        }

                        _face.color = face.color;
                        _face.material = material;

                        _face.z = ( v1.positionScreen.z + v2.positionScreen.z + v3.positionScreen.z ) / 3;

                        _renderData.elements.push( _face );

                    }

                }

            } else if ( object instanceof THREE.Line ) {

                if ( geometry instanceof THREE.BufferGeometry ) {

                    var attributes = geometry.attributes;

                    if ( attributes.position !== undefined ) {

                        var positions = attributes.position.array;

                        for ( var i = 0, l = positions.length; i < l; i += 3 ) {

                            renderList.pushVertex( positions[ i ], positions[ i + 1 ], positions[ i + 2 ] );

                        }

                        if ( attributes.index !== undefined ) {

                            var indices = attributes.index.array;

                            for ( var i = 0, l = indices.length; i < l; i += 2 ) {

                                renderList.pushLine( indices[ i ], indices[ i + 1 ] );

                            }

                        } else {

                            var step = object.mode === THREE.LinePieces ? 2 : 1;

                            for ( var i = 0, l = ( positions.length / 3 ) - 1; i < l; i += step ) {

                                renderList.pushLine( i, i + 1 );

                            }

                        }

                    }

                } else if ( geometry instanceof THREE.Geometry ) {

                    _modelViewProjectionMatrix.multiplyMatrices( _viewProjectionMatrix, _modelMatrix );

                    var vertices = object.geometry.vertices;

                    if ( vertices.length === 0 ) continue;

                    v1 = getNextVertexInPool();
                    v1.positionScreen.copy( vertices[ 0 ] ).applyMatrix4( _modelViewProjectionMatrix );

                    // Handle LineStrip and LinePieces
                    var step = object.mode === THREE.LinePieces ? 2 : 1;

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

                        v1 = getNextVertexInPool();
                        v1.positionScreen.copy( vertices[ v ] ).applyMatrix4( _modelViewProjectionMatrix );

                        if ( ( v + 1 ) % step > 0 ) continue;

                        v2 = _vertexPool[ _vertexCount - 2 ];

                        _clippedVertex1PositionScreen.copy( v1.positionScreen );
                        _clippedVertex2PositionScreen.copy( v2.positionScreen );

                        if ( clipLine( _clippedVertex1PositionScreen, _clippedVertex2PositionScreen ) === true ) {

                            // Perform the perspective divide
                            _clippedVertex1PositionScreen.multiplyScalar( 1 / _clippedVertex1PositionScreen.w );
                            _clippedVertex2PositionScreen.multiplyScalar( 1 / _clippedVertex2PositionScreen.w );

                            _line = getNextLineInPool();

                            _line.id = object.id;
                            _line.v1.positionScreen.copy( _clippedVertex1PositionScreen );
                            _line.v2.positionScreen.copy( _clippedVertex2PositionScreen );

                            _line.z = Math.max( _clippedVertex1PositionScreen.z, _clippedVertex2PositionScreen.z );

                            _line.material = object.material;

                            if ( object.material.vertexColors === THREE.VertexColors ) {

                                _line.vertexColors[ 0 ].copy( object.geometry.colors[ v ] );
                                _line.vertexColors[ 1 ].copy( object.geometry.colors[ v - 1 ] );

                            }

                            _renderData.elements.push( _line );

                        }

                    }

                }

            } else if ( object instanceof THREE.Sprite ) {

                _vector4.set( _modelMatrix.elements[ 12 ], _modelMatrix.elements[ 13 ], _modelMatrix.elements[ 14 ], 1 );
                _vector4.applyMatrix4( _viewProjectionMatrix );

                var invW = 1 / _vector4.w;

                _vector4.z *= invW;

                if ( _vector4.z >= - 1 && _vector4.z <= 1 ) {

                    _sprite = getNextSpriteInPool();
                    _sprite.id = object.id;
                    _sprite.x = _vector4.x * invW;
                    _sprite.y = _vector4.y * invW;
                    _sprite.z = _vector4.z;
                    _sprite.object = object;

                    _sprite.rotation = object.rotation;

                    _sprite.scale.x = object.scale.x * Math.abs( _sprite.x - ( _vector4.x + camera.projectionMatrix.elements[ 0 ] ) / ( _vector4.w + camera.projectionMatrix.elements[ 12 ] ) );
                    _sprite.scale.y = object.scale.y * Math.abs( _sprite.y - ( _vector4.y + camera.projectionMatrix.elements[ 5 ] ) / ( _vector4.w + camera.projectionMatrix.elements[ 13 ] ) );

                    _sprite.material = object.material;

                    _renderData.elements.push( _sprite );

                }

            }

        }

        if ( sortElements === true ) {

            _renderData.elements.sort( painterSort );

        }

        return _renderData;

    };

    // Pools

    function getNextObjectInPool() {

        if ( _objectCount === _objectPoolLength ) {

            var object = new THREE.RenderableObject();
            _objectPool.push( object );
            _objectPoolLength ++;
            _objectCount ++;
            return object;

        }

        return _objectPool[ _objectCount ++ ];

    }

    function getNextVertexInPool() {

        if ( _vertexCount === _vertexPoolLength ) {

            var vertex = new THREE.RenderableVertex();
            _vertexPool.push( vertex );
            _vertexPoolLength ++;
            _vertexCount ++;
            return vertex;

        }

        return _vertexPool[ _vertexCount ++ ];

    }

    function getNextFaceInPool() {

        if ( _faceCount === _facePoolLength ) {

            var face = new THREE.RenderableFace();
            _facePool.push( face );
            _facePoolLength ++;
            _faceCount ++;
            return face;

        }

        return _facePool[ _faceCount ++ ];


    }

    function getNextLineInPool() {

        if ( _lineCount === _linePoolLength ) {

            var line = new THREE.RenderableLine();
            _linePool.push( line );
            _linePoolLength ++;
            _lineCount ++
            return line;

        }

        return _linePool[ _lineCount ++ ];

    }

    function getNextSpriteInPool() {

        if ( _spriteCount === _spritePoolLength ) {

            var sprite = new THREE.RenderableSprite();
            _spritePool.push( sprite );
            _spritePoolLength ++;
            _spriteCount ++
            return sprite;

        }

        return _spritePool[ _spriteCount ++ ];

    }

    //

    function painterSort( a, b ) {

        if ( a.z !== b.z ) {

            return b.z - a.z;

        } else if ( a.id !== b.id ) {

            return a.id - b.id;

        } else {

            return 0;

        }

    }

    function clipLine( s1, s2 ) {

        var alpha1 = 0, alpha2 = 1,

        // Calculate the boundary coordinate of each vertex for the near and far clip planes,
        // Z = -1 and Z = +1, respectively.
            bc1near =  s1.z + s1.w,
            bc2near =  s2.z + s2.w,
            bc1far =  - s1.z + s1.w,
            bc2far =  - s2.z + s2.w;

        if ( bc1near >= 0 && bc2near >= 0 && bc1far >= 0 && bc2far >= 0 ) {

            // Both vertices lie entirely within all clip planes.
            return true;

        } else if ( ( bc1near < 0 && bc2near < 0 ) || ( bc1far < 0 && bc2far < 0 ) ) {

            // Both vertices lie entirely outside one of the clip planes.
            return false;

        } else {

            // The line segment spans at least one clip plane.

            if ( bc1near < 0 ) {

                // v1 lies outside the near plane, v2 inside
                alpha1 = Math.max( alpha1, bc1near / ( bc1near - bc2near ) );

            } else if ( bc2near < 0 ) {

                // v2 lies outside the near plane, v1 inside
                alpha2 = Math.min( alpha2, bc1near / ( bc1near - bc2near ) );

            }

            if ( bc1far < 0 ) {

                // v1 lies outside the far plane, v2 inside
                alpha1 = Math.max( alpha1, bc1far / ( bc1far - bc2far ) );

            } else if ( bc2far < 0 ) {

                // v2 lies outside the far plane, v2 inside
                alpha2 = Math.min( alpha2, bc1far / ( bc1far - bc2far ) );

            }

            if ( alpha2 < alpha1 ) {

                // The line segment spans two boundaries, but is outside both of them.
                // (This can't happen when we're only clipping against just near/far but good
                //  to leave the check here for future usage if other clip planes are added.)
                return false;

            } else {

                // Update the s1 and s2 vertices to match the clipped line segment.
                s1.lerp( s2, alpha1 );
                s2.lerp( s1, 1 - alpha2 );

                return true;

            }

        }

    }

};