CompressBarSeries.java

/*******************************************************************************
 * Copyright (c) 2008-2009 SWTChart project. All rights reserved. 
 * 
 * This code is distributed under the terms of the Eclipse Public License v1.0
 * which is available at http://www.eclipse.org/legal/epl-v10.html
 *******************************************************************************/
package org.swtchart.internal.compress;

import java.util.ArrayList;

/**
 * A compressor for bar series data.
 */
public class CompressBarSeries extends Compress
{

    /*
     * @see Compress#addNecessaryPlots(ArrayList, ArrayList, ArrayList)
     */
    @Override
    protected void addNecessaryPlots ( ArrayList<Double> xList, ArrayList<Double> yList, ArrayList<Integer> indexList )
    {

        double prevX = xSeries[0];
        double maxY = Double.NaN;
        int prevIndex = 0;

        for ( int i = 0; i < xSeries.length; i++ )
        {
            if ( xSeries[i] >= config.getXLowerValue () )
            {
                if ( isInSameGridXAsPrevious ( xSeries[i] ) )
                {
                    if ( maxY < ySeries[i] )
                    {
                        maxY = ySeries[i];
                    }
                }
                else
                {
                    if ( !Double.isNaN ( maxY ) )
                    {
                        addToList ( xList, yList, indexList, prevX, maxY, prevIndex );
                    }
                    prevX = xSeries[i];
                    maxY = ySeries[i];
                    prevIndex = i;
                }
            }

            if ( xSeries[i] > config.getXUpperValue () )
            {
                break;
            }
        }
        addToList ( xList, yList, indexList, prevX, maxY, prevIndex );
    }

    /**
     * Checks if the given x coordinate is in the same grid as previous.
     * 
     * @param x
     *            the X coordinate
     * @return true if the given coordinate is in the same grid as previous
     */
    private boolean isInSameGridXAsPrevious ( double x )
    {
        int xGridIndex = (int) ( ( x - config.getXLowerValue () ) / ( config.getXUpperValue () - config
                .getXLowerValue () ) * config.getWidthInPixel () );

        boolean isInSameGridAsPrevious = ( xGridIndex == previousXGridIndex );

        previousXGridIndex = xGridIndex;

        return isInSameGridAsPrevious;
    }
}