/*
 * [RoundCornerMath.java]
 *
 * Summary: draw RoundCornerMath.
 *
 * Copyright: (c) 2011-2017 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 2011-01-29 initial version.
 */
package com.mindprod.connectors;

import com.mindprod.connectors.RoundPolygon.RoundCornerCoordinates;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;

/**
 * draw RoundCornerMath.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2011-01-29 initial version.
 * @since 2011-01-29
 */
class RoundCornerMath extends ConnectorPanel
    {
    private static final int ANGLE_MARKER_RADIUS = 50;

    private static final int INNER_COIL_RADIUS = 20;

    private static final int LINE_FOR_COIL = 6;

    private static final int LINE_FOR_CONSTRUCTION = 10;

    private static final int LINE_FOR_RESULTS = 20;

    private static final int OUTER_COIL_RADIUS = 40;

    private static final int ROUNDING_RADIUS = 200;

    private static final int X1 = 100;

    private static final int X3 = 900;

    private static final int X5 = 200;

    private static final int Y1 = 900;

    private static final int Y3 = 600;

    private static final int Y5 = 50;

    private static final Color AXIS_COLOR = new Color( 0x0802000 );

    private static final Color CONSTRUCTION_COLOR = new Color( 0x000000 );

    private static final Color LETTERING_COLOR = new Color( 0x32cd32 );

    private static final Color RESULTS_COLOR = new Color( 0x80ff0000, true );

    private static final Color THETA_COLOR = Color.RED;

    RoundCornerMath()
        {
        super( 1000, 1000 );
        }

    /**
     * Fill in an angle with a pie shape to mark it.
     *
     * @param g      graphics context to draw on
     * @param x1     first point
     * @param y1     first point
     * @param x2     middle point
     * @param y2     middle point
     * @param x3     end point
     * @param y3     end point
     * @param radius radius of pie mark.
     */
    private static void markAngle( Graphics g, int x1, int y1, int x2, int y2, int x3, int y3, int radius )
        {
        double startAngle = Math.atan2( y2 - y1, x1 - x2 );
        if ( startAngle < 0 )
            {
            startAngle += Math.PI * 2;
            }
        double endAngle = Math.atan2( y2 - y3, x3 - x2 );
        if ( endAngle < 0 )
            {
            endAngle += Math.PI * 2;
            }
        double arcAngle = endAngle - startAngle;
        if ( arcAngle < 0 )
            {
            arcAngle += Math.PI * 2;
            }
        if ( arcAngle > Math.PI )
            {
            double temp = startAngle;
            startAngle = endAngle;
            endAngle = temp;
            arcAngle = endAngle - startAngle;
            if ( arcAngle < 0 )
                {
                arcAngle += Math.PI * 2;
                }
            }
        g.fillArc( x2 - radius,
                y2 - radius,
                radius * 2,
                radius * 2,
                ( int ) Math.floor( Math.toDegrees( startAngle ) + .5 ),
                ( int ) Math.floor( Math.toDegrees( arcAngle ) + .5 ) );
        }

    /**
     * draw diagram of the math used to computer rounded corners
     *
     * @param g where to paint
     */
    public void paintComponent( Graphics g )
        {
        super.paintComponent( g );
        final Graphics2D g2d = ( Graphics2D ) g;
        RoundCornerCoordinates c = RoundPolygon.computeCoordinates( X1, Y1, X3, Y3, X5, Y5, ROUNDING_RADIUS );
        final int xb = c.getXb();
        final int yb = c.getYb();
        final int hb = c.getHb();
        final int x2 = c.getX2();
        final int y2 = c.getY2();
        final int x4 = c.getX4();
        final int y4 = c.getY4();
        final int startAngle = c.getStartAngle();
        final int arcAngle = c.getArcAngle();
        final int x6 = xb + ROUNDING_RADIUS;
        final int y6 = yb + ROUNDING_RADIUS;
        // mark equal angles with a pie
        g2d.setColor( THETA_COLOR );
        // now in drawing coordinates.
        markAngle( g2d, X1, Y1, X3, Y3, x6, y6, ANGLE_MARKER_RADIUS );
        markAngle( g2d, x6, y6, X3, Y3, X5, Y5, ANGLE_MARKER_RADIUS );
        markAngle( g2d, x6, y6, x2, y2, x4, y4, ANGLE_MARKER_RADIUS );
        markAngle( g2d, x2, y2, x4, y4, x6, y6, ANGLE_MARKER_RADIUS );
        g2d.setStroke( new BasicStroke( LINE_FOR_CONSTRUCTION ) );
        g2d.setColor( AXIS_COLOR );
        g2d.drawLine( 0, Y3, 1000, Y3 ); // x axis
        g2d.drawLine( X3, 0, X3, 1000 ); // y axis
        // draw construction lines
        g2d.setStroke( new BasicStroke( LINE_FOR_CONSTRUCTION ) );
        g2d.setColor( CONSTRUCTION_COLOR );
        g2d.drawLine( X1, Y1, X3, Y3 );
        g2d.drawLine( X1, Y1, X1, Y3 );
        g2d.drawRect( xb, yb, hb, hb );
        g2d.drawOval( xb, yb, hb, hb );
        g2d.drawLine( X3, Y3, X5, Y5 );
        g2d.drawPolygon( new int[] { x6, x2, x4 }, new int[] { y6, y2, y4 }, 3 );
        g2d.drawLine( X3, Y3, x6, y6 );
        g2d.setStroke( new BasicStroke( LINE_FOR_RESULTS ) );
        g2d.setColor( RESULTS_COLOR );
        g2d.drawLine( X1, Y1, x2, y2 );
        g2d.drawArc( xb, yb, hb, hb, startAngle, arcAngle );
        g2d.drawLine( x4, y4, X5, Y5 );
        // show start and end angle
        g2d.setStroke( new BasicStroke( LINE_FOR_COIL ) );
        g2d.drawArc( x6 - INNER_COIL_RADIUS,
                y6 - INNER_COIL_RADIUS,
                INNER_COIL_RADIUS * 2,
                INNER_COIL_RADIUS * 2,
                0,
                c.getStartAngle() );
        g2d.drawArc( x6 - OUTER_COIL_RADIUS,
                y6 - OUTER_COIL_RADIUS,
                OUTER_COIL_RADIUS * 2,
                OUTER_COIL_RADIUS * 2,
                0,
                c.getStartAngle() + c.getArcAngle() );
        // mark the equal angles
        g2d.setColor( LETTERING_COLOR );
        g2d.setFont( new Font( "dialog", Font.PLAIN, 70 ) );
        drawCenteredString( g2d, "1", X1, Y1 );
        drawCenteredString( g2d, "2", x2, y2 );
        drawCenteredString( g2d, "3", X3, Y3 );
        drawCenteredString( g2d, "4", x4, y4 );
        drawCenteredString( g2d, "5", X5, Y5 );
        drawCenteredString( g2d, "b", xb, yb );
        drawCenteredString( g2d, "6", x6, y6 );
        }
    }