Application: gvSIG desktop

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

import java.awt.geom.AffineTransform;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class AffineTransformFunction extends AbstractFunction {

    public AffineTransformFunction() {

        super(

            "Numeric", 

            "AffineTransform", 

            Range.between(0, 6),

            "With 0 parameters create an AffineTransform representing the Identity transformation\n" +

            "With 6 parameters create an AffineTransform with the 6 specifiable entries of the 3x3 transformation matrix.",

            "AffineTransform({{m00}}, m10, m01, m11, m02, m12)",

            new String[]{

                "m00 - the X coordinate scaling element of the 3x3 matrix",

                "m10 - the Y coordinate shearing element of the 3x3 matrix",

                "m01 - the X coordinate shearing element of the 3x3 matrix",

                "m11 - the Y coordinate scaling element of the 3x3 matrix",

                "m02 - the X coordinate translation element of the 3x3 matrix",

                "m12 - the Y coordinate translation element of the 3x3 matrix"

            },

            "AffineTransform"

        );

    }

    @Override

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

        AffineTransform at;

        switch(args.length) {

            case 0:

                at = new AffineTransform();

                return at;

            case 6:

                double m00 = getDouble(args, 0);

                double m10 = getDouble(args, 0);

                double m01 = getDouble(args, 0);

                double m11 = getDouble(args, 0);

                double m02 = getDouble(args, 0);

                double m12 = getDouble(args, 0);

                at = new AffineTransform(m00, m10, m01, m11, m02, m12);

                return at;

            default:

                throw new IllegalArgumentException("The AffinaTransform function requires 0 or 6 parameters.");

        }

    }

}