FilterView.java

package dsp.filter.design;

import org.jtransforms.fft.FloatFFT_1D;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import dsp.filter.FilterFactory;
import dsp.filter.Window.WindowType;
import dsp.filter.fir.FIRFilterSpecification;
import dsp.filter.fir.remez.RemezFIRFilterDesigner;
import gui.control.CurveFittedAreaChart;
import javafx.collections.ObservableList;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.chart.XYChart.Series;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Priority;

public class FilterView extends BorderPane
{
	private final static Logger mLog = LoggerFactory.getLogger( FilterView.class );

	private CurveFittedAreaChart mImpulseChart;
	private NumberAxis mImpulseXAxis;
	private NumberAxis mImpulseYAxis;
	private CurveFittedAreaChart mDFTChart;
	private NumberAxis mDFTXAxis;
	private NumberAxis mDFTYAxis;
	private static final int FFT_SIZE = 4096;
	private FloatFFT_1D mFFT = new FloatFFT_1D( FFT_SIZE );
	
	public FilterView( float[] taps )
	{
		init();

		if( taps != null )
		{
			setImpulseTaps( taps );

			float[] dft = new float[ FFT_SIZE ];
			System.arraycopy( taps, 0, dft, 0, taps.length );
			
			mFFT.realForward( dft );
			
			setDFTTaps( convertDFTToDecibel( dft, taps.length ) );
		}
	}
	
	private void init()
	{
		HBox hbox = new HBox();
		
		mImpulseXAxis = new NumberAxis( 0.0, 0.5, 1.0 );
		mImpulseYAxis = new NumberAxis( -0.2, 1.2, .1 );
		
		mImpulseChart = new CurveFittedAreaChart( mImpulseXAxis, mImpulseYAxis );
		mImpulseChart.setLegendVisible( false );
		mImpulseChart.setHorizontalGridLinesVisible( false );
		mImpulseChart.setVerticalGridLinesVisible(false);
        mImpulseChart.setAlternativeColumnFillVisible(false);
        mImpulseChart.setAlternativeRowFillVisible(false);
        
        String css = FilterView.class.getResource( "FilterView.css" ).toExternalForm();
        mImpulseChart.getStylesheets().add( css );

        hbox.getChildren().add( mImpulseChart );
        HBox.setHgrow( mImpulseChart, Priority.ALWAYS );
        
		mDFTXAxis = new NumberAxis( 0.0, FFT_SIZE / 2, FFT_SIZE / 8 );
		mDFTYAxis = new NumberAxis( -200.0, 10.0, 10.0 );
		
		mDFTChart = new CurveFittedAreaChart( mDFTXAxis, mDFTYAxis );
		mDFTChart.setLegendVisible( false );
		mDFTChart.setHorizontalGridLinesVisible( false );
		mDFTChart.setVerticalGridLinesVisible(false);
        mDFTChart.setAlternativeColumnFillVisible(false);
        mDFTChart.setAlternativeRowFillVisible(false);
        mDFTChart.getStylesheets().add( css );
        
        hbox.getChildren().add( mDFTChart );
        HBox.setHgrow( mDFTChart, Priority.ALWAYS );

        setCenter( hbox );
	}
	
	public void setImpulseTaps( double[] taps )
	{
		float[] convertedTaps = new float[ taps.length ];
		
		for( int x = 0; x < taps.length; x++ )
		{
			convertedTaps[ x ] = (float)taps[ x ];
		}
		
		setImpulseTaps( convertedTaps );
	}
	
	public void setImpulseTaps( float[] taps )
	{
		double smallest = 0.0;
		double largest = 0.0;
		
        final XYChart.Series<Number, Number> series = new XYChart.Series<>();
        
        for( int x = 0; x < taps.length; x++ )
        {
        	if( taps[ x ] < smallest )
			{
        		smallest = taps[ x ];
			}
        	
        	if( taps[ x ] > largest )
        	{
        		largest = taps[ x ];
        	}

        	series.getData().add( new XYChart.Data<Number, Number>( x, taps[ x ] ) );
        }
        
        mImpulseXAxis.setLowerBound( 0.0 );
        mImpulseXAxis.setUpperBound( taps.length - 1 );
        mImpulseXAxis.setTickUnit( 1.0 );
        
        double padding = Math.abs( largest - smallest ) * .1;
        
        mImpulseYAxis.setLowerBound( smallest - padding );
        mImpulseYAxis.setUpperBound( largest + padding );
        mImpulseYAxis.setTickUnit( padding );

        ObservableList<Series<Number,Number>> list = mImpulseChart.getData();
        list.add( series );
	}
	
	public void setDFTTaps( float[] taps )
	{
		double smallest = 0.0;
		
        final XYChart.Series<Number, Number> series = new XYChart.Series<>();
        
        for( int x = 0; x < taps.length; x++ )
        {
        	if( taps[ x ] < smallest )
			{
        		smallest = taps[ x ];
			}
        	
        	series.getData().add( new XYChart.Data<Number, Number>( x, taps[ x ] ) );
        }
        
        ObservableList<Series<Number,Number>> list = mDFTChart.getData();
        list.add( series );
	}
	
    public float[] convertDFTToDecibel( float[] dft, int tapLength )
    {
		float[] decibels = new float[ dft.length / 2 ];

		int index = 0;
		
		for( int x = 0; x < decibels.length; x ++ )
		{
			index = x * 2;
			
			decibels[ x ] = 20.0f * (float)Math.log10( ( ( dft[ index ] * dft[ index ] ) + 
				  ( dft[ index + 1 ] * dft[ index + 1 ] ) ) );
		}

		return decibels;
    }
}