Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl.function.spatial;

import org.apache.commons.lang3.Range;

import org.cresques.cts.ICoordTrans;

import org.cresques.cts.IProjection;

import org.gvsig.expressionevaluator.DataTypes;

import org.gvsig.expressionevaluator.ExpressionRuntimeException;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractGeometryFunction;

import org.gvsig.fmap.crs.CRSFactory;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.tools.dataTypes.DataTypeUtils;

public class STTransformFunction extends AbstractGeometryFunction {

    public STTransformFunction() {

        super("OGC", "ST_Transform", Range.between(2,3));

    }

    @Override

    public boolean allowConstantFolding() {

        return true;

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

        IProjection  to_proj = null;

        IProjection from_proj = null;

        Integer to_srid = null;

        Geometry geom = getGeom(args, 0);

        switch(args.length) {

          case 2:

            to_srid = (Integer) DataTypeUtils.coerce(DataTypes.INT, getObject(args, 1),null);

            if( to_srid==null ) {

              to_proj = CRSFactory.getCRS(getStr(args, 1));

            } else {

              to_proj = CRSFactory.getCRS("EPSG:"+to_srid);

            }

            from_proj = geom.getProjection();

            break;

          case 3:

            to_srid = (Integer) DataTypeUtils.coerce(DataTypes.INT, getObject(args, 2),null);

            if( to_srid==null ) {

              to_proj = CRSFactory.getCRS(getStr(args, 2));

            } else {

              to_proj = CRSFactory.getCRS("EPSG:"+to_srid);

            }

            from_proj = CRSFactory.getCRS(getStr(args, 1));

            break;

          default:

            throw new ExpressionRuntimeException("Incorrect number of arguments.");

        }

        ICoordTrans ct = from_proj.getCT(to_proj);

        Geometry r = geom.cloneGeometry();

        r.reProject(ct);

        return r;

    }

}