// HexCanvas.java
//
//
// Copyright 2004, Ethan Bolker and Bogdan Calota

package edu.umb.cs.eb.folding;

import java.awt.*;

/**
 * Display a Grid of hexagons.
 * 
 * Use coordinate system to get hex neighbors:
 *
 * 0-0 1-0 2-0 3-0
 *   0-1 1-1 2-1 3-1
 *     0-2 1-2 2-2 3-2
 */
public class HexCanvas extends GridCanvas
{
    private static final int sqrt3 = (int)Math.sqrt(3);
    private int cellHeight   = (int)(cellRadius*Math.sqrt(3));
    private Polygon hexagon;

    public HexCanvas(int width, int height )
    {
	super(width, height);

	// this creates a hexagon of the proper size
	hexagon = new Polygon();
	hexagon.addPoint(cellRadius/2, 0);
	hexagon.addPoint(3*cellRadius/2, 0);
	hexagon.addPoint(2*cellRadius, sqrt3*cellRadius);
	hexagon.addPoint(3*cellRadius/2, 2*sqrt3*cellRadius);
	hexagon.addPoint(cellRadius/2, 2*sqrt3*cellRadius);
	hexagon.addPoint(0, sqrt3*cellRadius);
    }

    protected void setGrid( Grid grid ) {
	super.setGrid(grid);
	GridPoint min = getMin();
	GridPoint max = getMax();
	this.setSize( cellRadius*2*(max.x - min.x + max.y - min.y + 3) ,
		      (1+cellHeight)*(max.y - min.y + 3));
    }

    protected int getAcidRadius() 
    {
	return cellRadius;
    }

    protected GridPoint project( GridPoint p ) 
    {
	GridPoint spot= new GridPoint( (1+2*p.x+p.y)*cellRadius, 
				       p.y*cellHeight + cellRadius );
	return spot;
    }
}