/*
 * Copyright (c) 2001 Matthew Feldt. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided the copyright notice above is
 * retained.
 *
 * THIS SOFTWARE IS PROVIDED ''AS IS'' AND WITHOUT ANY EXPRESSED OR
 * IMPLIED WARRANTIES.
 */

/**
 * Circle.java
 *
 * Java Examples In A Nutshell Copyright (c) 2000 David Flanagan
 * Exercise 2-1:
 * Write a Circle Class that is similar to the Rect class. Define a move()
 * method and an isInside() method (Recall that a circle is defined as all
 * points within a given radius from the center. Test for insideness by using
 * the Pythagorean theorem to copmute the distance between a point and the
 * center of the circle.) Also, define a boundingBox() method that returns
 * the smallest Rect that encloses the complete Circle. Write a simple program
 * to test the methods you've implemented.
 *
 * @author Matthew Feldt <developer@feldt.com>
 * @version 1.0, 01/28/2001 9:09
 */

package com.feldt.examples.classes;
import com.davidflanagan.examples.classes.Rect;


class Circle {
	private int h, k, r;

	Circle(int x, int y, int radius) {
		h = x;
		k = y;
		r = radius;
	}

	public void move(int deltax, int deltay) {
		h += deltax;
		k += deltay;
	}

	public boolean isInside(int x, int y) {
		// standard equation of a circle
		// square(x - h) + square(y - k) = square(r)
		x -= h; x *= x;
		y -= k; y *= y;
		return ((x + y) < (r * r));
	}

	public Rect boundingBox() {
		return new Rect(h-r, k-r, h+r, k+r);
	}

	public String toString() {
		return "[" + h + ", " + k + "; " + r + "]";
	}

	/** test class */
	static class Test {
	   public static void main (String args[]) {
			/*
			 * create a circle and its respective bounding rectangle then
			 * print both - tests Circle.boundingBox() & Circle.toString()
			 */
			Circle c = new Circle(0, 0, 5);
			Rect r = c.boundingBox();
			System.out.println("Circle(0, 0, 5).toString(): " + c);
			System.out.println("boundingBox Rect: " + r);

			// test Circle.isInside()
			System.out.println("Circle" + c + " isInside(2, 2) = " +
				c.isInside(2, 2));
			System.out.println("Circle" + c + " isInside(1, 5) = " +
				c.isInside(1, 5));

			// test Circle.move()
			c.move(3, 3);
			System.out.println("c.move(3, 3): " + c);

			// test Circle.isInside() after move
			System.out.println("Circle" + c + " isInside(5, 5) = " +
				c.isInside(5, 5));
			System.out.println("Circle" + c + " isInside(4, 8) = " +
				c.isInside(4, 8));
		}
	}
}