Modul/node_modules/wkx/lib/geometry.js

module.exports = Geometry;

var Types = require('./types');
var Point = require('./point');
var LineString = require('./linestring');
var Polygon = require('./polygon');
var MultiPoint = require('./multipoint');
var MultiLineString = require('./multilinestring');
var MultiPolygon = require('./multipolygon');
var GeometryCollection = require('./geometrycollection');
var BinaryReader = require('./binaryreader');
var BinaryWriter = require('./binarywriter');
var WktParser = require('./wktparser');
var ZigZag = require('./zigzag.js');

function Geometry() {
    this.srid = undefined;
    this.hasZ = false;
    this.hasM = false;
}

Geometry.parse = function (value, options) {
    var valueType = typeof value;

    if (valueType === 'string' || value instanceof WktParser)
        return Geometry._parseWkt(value);
    else if (Buffer.isBuffer(value) || value instanceof BinaryReader)
        return Geometry._parseWkb(value, options);
    else
        throw new Error('first argument must be a string or Buffer');
};

Geometry._parseWkt = function (value) {
    var wktParser,
        srid;

    if (value instanceof WktParser)
        wktParser = value;
    else
        wktParser = new WktParser(value);

    var match = wktParser.matchRegex([/^SRID=(\d+);/]);
    if (match)
        srid = parseInt(match[1], 10);

    var geometryType = wktParser.matchType();
    var dimension = wktParser.matchDimension();

    var options = {
        srid: srid,
        hasZ: dimension.hasZ,
        hasM: dimension.hasM
    };

    switch (geometryType) {
        case Types.wkt.Point:
            return Point._parseWkt(wktParser, options);
        case Types.wkt.LineString:
            return LineString._parseWkt(wktParser, options);
        case Types.wkt.Polygon:
            return Polygon._parseWkt(wktParser, options);
        case Types.wkt.MultiPoint:
            return MultiPoint._parseWkt(wktParser, options);
        case Types.wkt.MultiLineString:
            return MultiLineString._parseWkt(wktParser, options);
        case Types.wkt.MultiPolygon:
            return MultiPolygon._parseWkt(wktParser, options);
        case Types.wkt.GeometryCollection:
            return GeometryCollection._parseWkt(wktParser, options);
    }
};

Geometry._parseWkb = function (value, parentOptions) {
    var binaryReader,
        wkbType,
        geometryType,
        options = {};

    if (value instanceof BinaryReader)
        binaryReader = value;
    else
        binaryReader = new BinaryReader(value);

    binaryReader.isBigEndian = !binaryReader.readInt8();

    wkbType = binaryReader.readUInt32();

    options.hasSrid = (wkbType & 0x20000000) === 0x20000000;
    options.isEwkb = (wkbType & 0x20000000) || (wkbType & 0x40000000) || (wkbType & 0x80000000);

    if (options.hasSrid)
        options.srid = binaryReader.readUInt32();

    options.hasZ = false;
    options.hasM = false;

    if (!options.isEwkb && (!parentOptions || !parentOptions.isEwkb)) {
        if (wkbType >= 1000 && wkbType < 2000) {
            options.hasZ = true;
            geometryType = wkbType - 1000;
        }
        else if (wkbType >= 2000 && wkbType < 3000) {
            options.hasM = true;
            geometryType = wkbType - 2000;
        }
        else if (wkbType >= 3000 && wkbType < 4000) {
            options.hasZ = true;
            options.hasM = true;
            geometryType = wkbType - 3000;
        }
        else {
            geometryType = wkbType;
        }
    }
    else {
        if (wkbType & 0x80000000)
            options.hasZ = true;
        if (wkbType & 0x40000000)
            options.hasM = true;

        geometryType = wkbType & 0xF;
    }

    switch (geometryType) {
        case Types.wkb.Point:
            return Point._parseWkb(binaryReader, options);
        case Types.wkb.LineString:
            return LineString._parseWkb(binaryReader, options);
        case Types.wkb.Polygon:
            return Polygon._parseWkb(binaryReader, options);
        case Types.wkb.MultiPoint:
            return MultiPoint._parseWkb(binaryReader, options);
        case Types.wkb.MultiLineString:
            return MultiLineString._parseWkb(binaryReader, options);
        case Types.wkb.MultiPolygon:
            return MultiPolygon._parseWkb(binaryReader, options);
        case Types.wkb.GeometryCollection:
            return GeometryCollection._parseWkb(binaryReader, options);
        default:
            throw new Error('GeometryType ' + geometryType + ' not supported');
    }
};

Geometry.parseTwkb = function (value) {
    var binaryReader,
        options = {};

    if (value instanceof BinaryReader)
        binaryReader = value;
    else
        binaryReader = new BinaryReader(value);

    var type = binaryReader.readUInt8();
    var metadataHeader = binaryReader.readUInt8();

    var geometryType = type & 0x0F;
    options.precision = ZigZag.decode(type >> 4);
    options.precisionFactor = Math.pow(10, options.precision);

    options.hasBoundingBox = metadataHeader >> 0 & 1;
    options.hasSizeAttribute = metadataHeader >> 1 & 1;
    options.hasIdList = metadataHeader >> 2 & 1;
    options.hasExtendedPrecision = metadataHeader >> 3 & 1;
    options.isEmpty = metadataHeader >> 4 & 1;

    if (options.hasExtendedPrecision) {
        var extendedPrecision = binaryReader.readUInt8();
        options.hasZ = (extendedPrecision & 0x01) === 0x01;
        options.hasM = (extendedPrecision & 0x02) === 0x02;

        options.zPrecision = ZigZag.decode((extendedPrecision & 0x1C) >> 2);
        options.zPrecisionFactor = Math.pow(10, options.zPrecision);

        options.mPrecision = ZigZag.decode((extendedPrecision & 0xE0) >> 5);
        options.mPrecisionFactor = Math.pow(10, options.mPrecision);
    }
    else {
        options.hasZ = false;
        options.hasM = false;
    }

    if (options.hasSizeAttribute)
        binaryReader.readVarInt();
    if (options.hasBoundingBox) {
        var dimensions = 2;

        if (options.hasZ)
            dimensions++;
        if (options.hasM)
            dimensions++;

        for (var i = 0; i < dimensions; i++) {
            binaryReader.readVarInt();
            binaryReader.readVarInt();
        }
    }

    switch (geometryType) {
        case Types.wkb.Point:
            return Point._parseTwkb(binaryReader, options);
        case Types.wkb.LineString:
            return LineString._parseTwkb(binaryReader, options);
        case Types.wkb.Polygon:
            return Polygon._parseTwkb(binaryReader, options);
        case Types.wkb.MultiPoint:
            return MultiPoint._parseTwkb(binaryReader, options);
        case Types.wkb.MultiLineString:
            return MultiLineString._parseTwkb(binaryReader, options);
        case Types.wkb.MultiPolygon:
            return MultiPolygon._parseTwkb(binaryReader, options);
        case Types.wkb.GeometryCollection:
            return GeometryCollection._parseTwkb(binaryReader, options);
        default:
            throw new Error('GeometryType ' + geometryType + ' not supported');
    }
};

Geometry.parseGeoJSON = function (value) {
    return Geometry._parseGeoJSON(value);
};

Geometry._parseGeoJSON = function (value, isSubGeometry) {
    var geometry;

    switch (value.type) {
        case Types.geoJSON.Point:
            geometry = Point._parseGeoJSON(value); break;
        case Types.geoJSON.LineString:
            geometry = LineString._parseGeoJSON(value); break;
        case Types.geoJSON.Polygon:
            geometry = Polygon._parseGeoJSON(value); break;
        case Types.geoJSON.MultiPoint:
            geometry = MultiPoint._parseGeoJSON(value); break;
        case Types.geoJSON.MultiLineString:
            geometry = MultiLineString._parseGeoJSON(value); break;
        case Types.geoJSON.MultiPolygon:
            geometry = MultiPolygon._parseGeoJSON(value); break;
        case Types.geoJSON.GeometryCollection:
            geometry = GeometryCollection._parseGeoJSON(value); break;
        default:
            throw new Error('GeometryType ' + value.type + ' not supported');
    }

    if (value.crs && value.crs.type && value.crs.type === 'name' && value.crs.properties && value.crs.properties.name) {
        var crs = value.crs.properties.name;

        if (crs.indexOf('EPSG:') === 0)
            geometry.srid = parseInt(crs.substring(5));
        else if (crs.indexOf('urn:ogc:def:crs:EPSG::') === 0)
            geometry.srid = parseInt(crs.substring(22));
        else
            throw new Error('Unsupported crs: ' + crs);
    }
    else if (!isSubGeometry) {
        geometry.srid = 4326;
    }

    return geometry;
};

Geometry.prototype.toEwkt = function () {
    return 'SRID=' + this.srid + ';' + this.toWkt();
};

Geometry.prototype.toEwkb = function () {
    var ewkb = new BinaryWriter(this._getWkbSize() + 4);
    var wkb = this.toWkb();

    ewkb.writeInt8(1);
    ewkb.writeUInt32LE((wkb.slice(1, 5).readUInt32LE(0) | 0x20000000) >>> 0, true);
    ewkb.writeUInt32LE(this.srid);

    ewkb.writeBuffer(wkb.slice(5));

    return ewkb.buffer;
};

Geometry.prototype._getWktType = function (wktType, isEmpty) {
    var wkt = wktType;

    if (this.hasZ && this.hasM)
        wkt += ' ZM ';
    else if (this.hasZ)
        wkt += ' Z ';
    else if (this.hasM)
        wkt += ' M ';

    if (isEmpty && !this.hasZ && !this.hasM)
        wkt += ' ';

    if (isEmpty)
        wkt += 'EMPTY';

    return wkt;
};

Geometry.prototype._getWktCoordinate = function (point) {
    var coordinates = point.x + ' ' + point.y;

    if (this.hasZ)
        coordinates += ' ' + point.z;
    if (this.hasM)
        coordinates += ' ' + point.m;

    return coordinates;
};

Geometry.prototype._writeWkbType = function (wkb, geometryType, parentOptions) {
    var dimensionType = 0;

    if (typeof this.srid === 'undefined' && (!parentOptions || typeof parentOptions.srid === 'undefined')) {
        if (this.hasZ && this.hasM)
            dimensionType += 3000;
        else if (this.hasZ)
            dimensionType += 1000;
        else if (this.hasM)
            dimensionType += 2000;
    }
    else {
        if (this.hasZ)
            dimensionType |= 0x80000000;
        if (this.hasM)
            dimensionType |= 0x40000000;
    }

    wkb.writeUInt32LE((dimensionType + geometryType) >>> 0, true);
};

Geometry.getTwkbPrecision = function (xyPrecision, zPrecision, mPrecision) {
    return {
        xy: xyPrecision,
        z: zPrecision,
        m: mPrecision,
        xyFactor: Math.pow(10, xyPrecision),
        zFactor: Math.pow(10, zPrecision),
        mFactor: Math.pow(10, mPrecision)
    };
};

Geometry.prototype._writeTwkbHeader = function (twkb, geometryType, precision, isEmpty) {
    var type = (ZigZag.encode(precision.xy) << 4) + geometryType;
    var metadataHeader = (this.hasZ || this.hasM) << 3;
    metadataHeader += isEmpty << 4;

    twkb.writeUInt8(type);
    twkb.writeUInt8(metadataHeader);

    if (this.hasZ || this.hasM) {
        var extendedPrecision = 0;
        if (this.hasZ)
            extendedPrecision |= 0x1;
        if (this.hasM)
            extendedPrecision |= 0x2;

        twkb.writeUInt8(extendedPrecision);
    }
};

Geometry.prototype.toGeoJSON = function (options) {
    var geoJSON = {};

    if (this.srid) {
        if (options) {
            if (options.shortCrs) {
                geoJSON.crs = {
                    type: 'name',
                    properties: {
                        name: 'EPSG:' + this.srid
                    }
                };
            }
            else if (options.longCrs) {
                geoJSON.crs = {
                    type: 'name',
                    properties: {
                        name: 'urn:ogc:def:crs:EPSG::' + this.srid
                    }
                };
            }
        }
    }

    return geoJSON;
};