/*
 * [Spectrum.java]
 *
 * Summary: Sample program to draw three spectra.
 *
 * Copyright: (c) 1998-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 1998-01-01 initial version
 */
package com.mindprod.wavelength;

import com.mindprod.common18.FontFactory;

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;

/**
 * Sample program to draw three spectra.
 * <p/>
 * Uses the com.mindprod.wavelength package.
 * <p/>
 * The classes Spectrum, Display, FCanvas, HCanvas and WCanvas
 * are just for demonstrating the Wavelength class.  They are not
 * needed to use it in your own applications.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 1998-01-01 initial version
 * @since 1998-01-01
 */
public final class Spectrum
    {
    public static void main( String[] args )
        {
        Frame frame = new Frame( "Spectrum" );
        frame.setSize( 500, 400 );
        frame.setLayout( null );
        frame.setBackground( Color.WHITE );
        // frequency spectrum
        FCanvas t = new FCanvas();
        t.setBackground( Color.WHITE );
        t.setForeground( Color.BLACK );
        t.setLocation( 0, 50 );
        t.setSize( 500, 50 );
        frame.add( t );
        // wavelength spectrum
        WCanvas w = new WCanvas();
        w.setBackground( Color.WHITE );
        w.setForeground( Color.BLACK );
        w.setLocation( 0, 150 );
        w.setSize( 500, 50 );
        frame.add( w );
        // hue spectrum
        HCanvas h = new HCanvas();
        h.setBackground( Color.WHITE );
        h.setForeground( Color.BLACK );
        h.setLocation( 0, 250 );
        h.setSize( 500, 50 );
        frame.add( h );
        frame.validate();
        frame.setVisible( true );
        frame.addWindowListener( new java.awt.event.WindowAdapter()
            {
            /**
             * Handle request to shutdown.
             * @param e event giving details of closing.
             */
            public void windowClosing( java.awt.event.WindowEvent e )
                {
                System.exit( 0 );
                } // end WindowClosing
            } // end anonymous class
        );// end addWindowListener line
        } // end main
    } // end Spectrum

/**
 * draw a spectrum by frequency, a realistic rainbow
 */
final class FCanvas extends Canvas
    {
    private static final int BORDER = 25;

    private static final int DATAPOINTS = 400;

    // range we plot wavelengths over
    private static final int FREQUENCY_START = 380;

    private static final int FREQUENCY_STOP = 790;

    public void paint( Graphics g )
        {
        // for text
        Font little = FontFactory.build( "Dialog", Font.PLAIN, 10 );
        FontMetrics littlefm = getFontMetrics( little );
        Font big = FontFactory.build( "Dialog", Font.BOLD, 14 );
        FontMetrics bigfm = getFontMetrics( big );
        // draw the Light spectrum
        for ( int i = 0; i < DATAPOINTS; i++ )
            {
            float freq =
                    ( FREQUENCY_STOP - FREQUENCY_START ) * i
                    / ( float ) DATAPOINTS + FREQUENCY_START;
            Color shade = Wavelength.fColor( freq, 1.0f );
            g.setColor( shade );
            g.drawLine( i + BORDER, 0, i + BORDER, 50 );
            } // end for
        // must do legends in a second pass to avoid spectrum overlaying.
        // title for nm
        g.setFont( big );
        g.setColor( Color.BLACK );
        String title = "Frequency (Terahertz)";
        // x,y is bottom left corner of text
        g.drawString( title,
                DATAPOINTS / 2 + BORDER - bigfm.stringWidth( title ) / 2,
                40 );
        g.setFont( little );
        g.setColor( Color.GRAY );
        // draw nm ticks and numbering every 50
        final int span = FREQUENCY_STOP - FREQUENCY_START;
        for ( int tick = FREQUENCY_START; tick <= FREQUENCY_STOP; tick += 50 )
            {
            int tickPix =
                    ( ( tick - FREQUENCY_START ) * DATAPOINTS ) / span + BORDER;
            g.drawLine( tickPix, 0, tickPix, 5 );
            String tickString = String.valueOf( tick );
            g.drawString( tickString,
                    tickPix - littlefm.stringWidth( tickString ) / 2,
                    20 );
            } // end for
        } // end paint
    } // end FCanvas

/**
 * draw a wavelength spectrum, a realistic rainbow
 */
final class WCanvas extends Canvas
    {
    private static final int BORDER = 25;

    private static final int DATAPOINTS = 400;

    // range we plot wavelenths over
    private static final int WAVELENGTH_START = 380;

    private static final int WAVELENGTH_STOP = 780;

    public void paint( Graphics g )
        {
        Graphics2D g2d = ( Graphics2D ) g;
        g2d.setRenderingHint( RenderingHints.KEY_TEXT_ANTIALIASING,
                RenderingHints.VALUE_TEXT_ANTIALIAS_ON );
        g2d.setRenderingHint( RenderingHints.KEY_RENDERING,
                RenderingHints.VALUE_RENDER_QUALITY );
        // if wanted to smooth geometric shapes too
        // g2d.setRenderingHint( RenderingHints.KEY_ANTIALIASING,
        // RenderingHints.VALUE_ANTIALIAS_ON );
        // for text
        Font little = FontFactory.build( "Dialog", Font.PLAIN, 10 );
        FontMetrics littlefm = getFontMetrics( little );
        Font big = FontFactory.build( "Dialog", Font.BOLD, 14 );
        FontMetrics bigfm = getFontMetrics( big );
        // draw the Light spectrum
        for ( int i = 0; i < DATAPOINTS; i++ )
            {
            float wl =
                    ( WAVELENGTH_STOP - WAVELENGTH_START ) * i
                    / ( float ) DATAPOINTS + WAVELENGTH_START;
            Color shade = Wavelength.wvColor( wl, 1.0f );
            g.setColor( shade );
            g.drawLine( i + BORDER, 0, i + BORDER, 50 );
            } // end for
        // must do legends in a second pass to avoid spectrum overlaying.
        // title for nm
        g.setFont( big );
        g.setColor( Color.BLACK );
        String title = "Wavelength (nm)";
        g.drawString( title,
                DATAPOINTS / 2 + BORDER - bigfm.stringWidth( title ) / 2,
                40 );
        g.setFont( little );
        g.setColor( Color.GRAY );
        // draw nm ticks and numbering every 50
        final int span = WAVELENGTH_STOP - WAVELENGTH_START;
        for ( int tick = WAVELENGTH_START; tick <= WAVELENGTH_STOP; tick += 50 )
            {
            int tickPix =
                    ( ( tick - WAVELENGTH_START ) * DATAPOINTS ) / span
                    + BORDER;
            g.drawLine( tickPix, 0, tickPix, 5 );
            String tickString = String.valueOf( tick );
            g.drawString( tickString,
                    tickPix - littlefm.stringWidth( tickString ) / 2,
                    20 );
            } // end for
        } // end paint
    } // end WCanvas

/**
 * draw a hue Spectrum
 */
final class HCanvas extends Canvas
    {
    private static final int BORDER = 25;

    private static final int DATAPOINTS = 400;

    public void paint( Graphics g )
        {
        // for text
        Font little = FontFactory.build( "Dialog", Font.PLAIN, 10 );
        FontMetrics littlefm = getFontMetrics( little );
        Font big = FontFactory.build( "Dialog", Font.BOLD, 14 );
        FontMetrics bigfm = getFontMetrics( big );
        // draw the Hue spectrum
        for ( int i = 0; i < DATAPOINTS; i++ )
            {
            float hue = i / ( float ) DATAPOINTS;
            Color shade = new Color( Color.HSBtoRGB( hue, 1, 1 ) );
            g.setColor( shade );
            g.drawLine( i + BORDER, 0, i + BORDER, 50 );
            } // end for
        // must do legends in a second pass to avoid spectrum overlaying.
        // title for nm
        g.setFont( big );
        g.setColor( Color.BLACK );
        String title = "Java Hue";
        g.drawString( title,
                DATAPOINTS / 2 + BORDER - bigfm.stringWidth( title ) / 2,
                40 );
        g.setFont( little );
        g.setColor( Color.BLACK );
        // draw hue ticks and numbering every 0.1
        for ( int tick = 0; tick <= 10; tick++ )
            {
            int tickPix = tick * DATAPOINTS / 10 + BORDER;
            g.drawLine( tickPix, 0, tickPix, 5 );
            String tickString = Display.oneDec( tick );
            g.drawString( tickString,
                    tickPix - littlefm.stringWidth( tickString ) / 2,
                    20 );
            } // end for
        } // end paint
    } // end HCanvas

final class Display
    {
    public static String oneDec( int i )
        {
        String s = Integer.toString( i );
        switch ( s.length() )
            {
            case 0:
                s = "0.0";
                break;
            case 1:
                s = "0." + s;
                break;
            default:
                s =
                        s.substring( 0, s.length() - 1 )
                        + '.'
                        + s.substring( s.length() - 1 );
                break;
            } // end switch
        return s;
        } // end oneDec
    } // end HDisplay