/* 
 * This code is part of Project Waterloo from King's College London
 * 
 *
 * Copyright King's College London 2012-
 * 
 * @author Malcolm Lidierth, King's College London  [Contact]
 * 
 * Project Waterloo is free software:  you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Project Waterloo 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see .
 *
 */
package kcl.waterloo.graphics.transforms;

import java.util.ArrayList;

import kcl.waterloo.graphics.GJUtilities;

/**
 *
 * @author Malcolm Lidierth, King's College London  [Contact]
 */
public final class Log2Transform extends GJAbstractDataTransform {

    final static Log2Transform Instance = new Log2Transform();
    private static final long serialVersionUID = 1L;
    private static final ArrayList minorGrid = minorGridMaker();
    private static final ArrayList majorGrid = majorGridMaker();

    private Log2Transform() {
        super();
    }

    public static Log2Transform getInstance() {
        return Instance;
    }

    @Override
    public String getName() {
        return "log2";
    }

    @Override
    public final double getData(double val) {
        val = Math.log(val) / Math.log(2.0d);
        return val;
    }

    @Override
    public final double[] getData(final double[] arr) {
        for (int k = 0; k < arr.length; k++) {
            arr[k] = Math.log(arr[k]) / Math.log(2.0d);
        }
        return arr;
    }

    @Override
    public final double getInverse(double val) {
        return Math.pow(2, val);
    }

    @Override
    public final String getTickLabel(double val) {
        return "2" + GJUtilities.getSuperscripts(nf.format(val));
    }

    @Override
    public ArrayList getAxisTickPositions(double start, double stop, double inc) {
        start = Math.pow(2, start);
        stop = Math.pow(2, stop);
        if (start <= 0) {
            start = stop / 1000d;
        }
        int idx0 = 0, idx1 = majorGrid.size() - 1;
        for (int k = 1; k < majorGrid.size() - 1; k++) {
            if (Math.pow(2, majorGrid.get(k)) > start) {
                idx0 = k - 1;
                break;
            }
        }
        for (int k = 1; k < majorGrid.size() - 3; k++) {
            if (Math.pow(2, majorGrid.get(k)) > stop) {
                idx1 = k + 2;
                break;
            }
        }
        return new ArrayList(majorGrid.subList(idx0, idx1));
    }

    private static ArrayList majorGridMaker() {
        ArrayList pos = new ArrayList();
        for (double s = -53d; s <= 53d; s++) {
            pos.add(s);
        }
        return pos;
    }

    @Override
    public ArrayList getMinorGridPositions(double start, double stop, double inc, int n) {
        return minorGrid;
    }

    private static ArrayList minorGridMaker() {
        return new ArrayList();
    }
}