com.golemgame.util.TransformationFunction.java Source code

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Here is the source code for com.golemgame.util.TransformationFunction.java

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/*******************************************************************************
 * Copyright 2008, 2009, 2010 Sam Bayless.
 * 
 *     This file is part of Golems.
 * 
 *     Golems is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 * 
 *     Golems is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 * 
 *     You should have received a copy of the GNU General Public License
 *     along with Golems. If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package com.golemgame.util;

import java.io.Serializable;

import org.apache.commons.math.FunctionEvaluationException;
import org.apache.commons.math.analysis.UnivariateRealFunction;

public class TransformationFunction implements UnivariateRealFunction, KnottedFunction, Serializable {
    static final long serialVersionUID = 1;
    private UnivariateRealFunction function;
    private double translateX = 0;
    private double translateY = 0;
    private double scaleX = 1;
    private double scaleY = 1;

    public TransformationFunction(UnivariateRealFunction toChain) {

        this.function = toChain;

    }

    public TransformationFunction() {
        super();
    }

    public double value(double x) throws FunctionEvaluationException {

        return transformValue(x, function);

    }

    protected double transformValue(double x, UnivariateRealFunction function) throws FunctionEvaluationException {
        double tempY = scaleY;
        if (tempY == 0)//avoid division by zero.
            tempY = Double.MIN_VALUE;
        return (function.value((x - translateX) * scaleX) / scaleY + translateY);
    }

    public double getTranslateX() {
        return translateX;
    }

    public void setTranslateX(double translateX) {
        this.translateX = translateX;
    }

    public double getTranslateY() {
        return translateY;
    }

    public void setTranslateY(double translateY) {
        this.translateY = translateY;
    }

    public double getScaleX() {
        return scaleX;
    }

    public void setScaleX(double scaleX) {
        this.scaleX = scaleX;
    }

    public double getScaleY() {
        return scaleY;
    }

    public void setScaleY(double scaleY) {
        this.scaleY = scaleY;
    }

    public void resetTransform() {
        translateX = 0;
        translateY = 0;
        scaleX = 1;
        scaleY = 1;
    }

    public void setTranslate(double translateX, double translateY) {
        this.translateX = translateX;
        this.translateY = translateY;
    }

    public void setScale(double scaleX, double scaleY) {
        this.scaleX = scaleX;
        this.scaleY = scaleY;
    }

    public void setTransform(double translateX, double translateY, double scaleX, double scaleY) {
        this.translateX = translateX;
        this.scaleX = scaleX;
        this.translateY = translateY;
        this.scaleY = scaleY;
    }

    public void setFunction(UnivariateRealFunction function) {
        this.function = function;
    }

    public double invertY(double y) {
        return (y - translateY) * scaleY;
    }

    public double invertX(double x) {
        return (x - translateX) * scaleX;
    }

    public double transformX(double x) {
        return (x / scaleX) + translateX;
    }

    public double transformY(double y) {
        return (y / scaleY) + translateY;
    }

    public UnivariateRealFunction getFunction() {
        return function;
    }

    public double[] getXKnots() {
        if (this.getFunction() instanceof KnottedFunction) {
            KnottedFunction knotted = ((KnottedFunction) this.getFunction());
            if (knotted.isKnotted()) {
                return knotted.getXKnots();
            }
        }
        return null;
    }

    public int count() {
        if (this.getFunction() instanceof KnottedFunction) {
            KnottedFunction knotted = ((KnottedFunction) this.getFunction());
            if (knotted.isKnotted()) {
                return knotted.count();
            }
        }
        return 0;
    }

    public double[] getYKnots() {
        if (this.getFunction() instanceof KnottedFunction) {
            KnottedFunction knotted = ((KnottedFunction) this.getFunction());
            if (knotted.isKnotted()) {
                return knotted.getYKnots();
            }
        }
        return null;
    }

    public boolean isKnotted() {
        if (this.getFunction() instanceof KnottedFunction) {
            return ((KnottedFunction) this.getFunction()).isKnotted();
        } else
            return false;
    }

}