/*
 *  ==========================================================================
 *  GraphicsGrid.java: Definition and Management of the Graphics Grid....
 *
 *  Written By : Mark Austin                                      October 2005
 *  ==========================================================================
 */

import java.lang.Math.*;
import java.applet.*;
import java.util.*;
import java.io.*;
import java.text.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.Color;
import java.awt.font.*;
import java.awt.image.*;
import java.awt.geom.*;   // Needed for affine transformation....
import java.net.URL;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class GraphicsGrid {

    // Define fidelity for grid size....

    private int gridSize = 50;
    private int xBorder  = 40;
    private int yBorder  = 40;
    private int smallDotSize = 3;

    // Constructor methods ....

    public GraphicsGrid() {}

    public void drawGrid( Graphics gs, int width, int height ) {

       // Setup Affine Transformation and 2D graphics context ....

       AffineTransform at = new AffineTransform();
       at.translate(  xBorder, height - yBorder );
       at.scale( 1, -1);

       Graphics2D g2D = (Graphics2D) gs;
       g2D.setTransform (at);

       // Draw grid in pixel coordinates ....

       int iHorizontalDistance = width  - 2*xBorder;
       int iVerticalDistance   = height - 2*yBorder;

       Ellipse2D dot = new Ellipse2D.Double( 0, 0, (int) 5, (int) 5 );

       for (int i = 0; i <=  iHorizontalDistance; i = i + gridSize )
       for (int j = 0; j <=  iVerticalDistance; j = j + gridSize ) {

           // Adjust color for x- and y- axes ....

           if ( i == 0 || j == 0 )
              g2D.setColor( Color.red );
           else
              g2D.setColor( Color.blue );

           // Draw grid dot ....

           g2D.translate(  i, j );
           g2D.scale(  (double) 1.0, (double) -1.0 );
           g2D.fill( dot );
           g2D.scale(  (double) 1.0, (double) -1.0 );
           g2D.translate( -i,-j );
       }
    }
}