Application: gvSIG desktop

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

import org.apache.commons.lang3.Range;

import org.apache.commons.lang3.StringUtils;

import org.apache.commons.math.util.MathUtils;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractGeometryFunction;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.GeometryLocator;

import org.gvsig.fmap.geom.primitive.Point;

public class PointByAngleFunction extends AbstractGeometryFunction {

    public PointByAngleFunction() {

        super("OGC", "PointByAngle", Range.between(3, 5));

    }

    @Override

    public boolean allowConstantFolding() {

        return true;

    }

    @Override

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

        Object arg1 = getObject(args, 0);

        try {

            arg1 = getDouble(args, 0);

        } catch (Exception ex) {

            arg1 = getObject(args, 0);

        }

        // default value in sexagesimal grades 360?

        // operations in radians

        String unit = "s";

        Point pointGeom;           

        double distance;

        double angle;

        if (!(arg1 instanceof Number)) {

            //3 or 4 args

            //(geom, distance, angle, unit='s')

            Geometry argGeom = GeometryLocator.getGeometryManager().createFrom(arg1);

            if(argGeom == null) {

                throw new RuntimeException("Geometry can't be null");

            }

            pointGeom = argGeom.centroid();

            if (args.length == 4) {

                unit = this.getStr(args, 3);

            }

            distance = getDouble(args, 1);

            angle = getDouble(args, 2);

        } else {

            //4 or 5 args

            //(x, y, distance, angle, unit='s')

            double x1 = (double) arg1;

            double x2 = getDouble(args, 1);

            pointGeom = GeometryLocator.getGeometryManager().createPoint(x1, x2, Geometry.SUBTYPES.GEOM2D);

            if(pointGeom == null) {

                throw new RuntimeException("Geometry can't be null");

            }

            if (args.length == 5) {

                unit = this.getStr(args, 4);

            }

            distance = getDouble(args, 2);

            angle = getDouble(args, 3);

        }

        if (StringUtils.equals(unit, "s")){

            angle = MathUtils.round(Math.toRadians(angle), 8);

        } else if (StringUtils.equals(unit, "g")) {

            angle = Math.PI * angle / 200;

        }

        double deltaX = distance * MathUtils.round(Math.cos(angle), 8);

        double deltaY = distance * MathUtils.round(Math.sin(angle), 8);

        pointGeom.move(deltaX, deltaY);

        return pointGeom;

    }

}