/***************************************************************************

hockey.js - Play hockey and make a puck bounce off the side of an image

<IMG SRC = "whatever" NAME = "hockey" >

The size of the image is the playing field. The puck and field dimensions 
are in multiples of 16. When the puck reaches the right edge the player 
loses. The player must get the puck through a slot the size 
of the puck on the left side of the image. The pointer must be within a 
box as high as the playing field and as wide as the puck. When the pointer 
contacts the edge of the puck (virtually square) the puck reverses with a 
mirror dy equal to the distance of the pointer from the center of the puck. 
The speed increases as play continues.

***************************************************************************/

var timer_id = 0;
var mouse_x, mouse_y;
var puck_x, puck_y, puck_dx, puck_dy;

var score_high = -1, score_miss = 0;

/***************************************************************************

  Startup initialization

  This source depends on the functions provided in Tools.c which
  must be included before this source file.

  <SCR IPT TYPE = "text/javascript" SRC = "../Tools.c"></SCRIPT>

  <SCR IPT TYPE = "text/javascript" SRC = "Hockey.c"></SCRIPT>

***************************************************************************/

Sprite_Make ("Puck");
Sprite_Move (Hockey, Puck, 0, 120);

Sprite_Make ("Pointer");
Sprite_Move (Hockey, Pointer, 544, 136);

Scores_List ();

document.onmousemove = handlerMM;
document.onclick = Play_Start;

Hockey_Message.innerText = "Click to start the game.";

/***************************************************************************

***************************************************************************/
function handlerMM ()
	{

	mouse_x = document.body.scrollLeft + window.event.clientX - Hockey.offsetLeft;
	mouse_y = document.body.scrollTop + window.event.clientY - Hockey.offsetTop;
	if (mouse_y < 16)
		mouse_y = 16;
	if (mouse_y > 256)
		mouse_y = 256;
	if (puck_dx)
		Sprite_Move (Hockey, Pointer, 544, mouse_y);
	}

/***************************************************************************

***************************************************************************/
function Play_Start () 
	{

	// Already playing?
	if (puck_dx)
		return;

	if (score_high < 0)
		{
		score_miss = 0;
		score_high = 0;
		Score_High.innerText = score_high;
		Score_Miss.innerText = score_miss;
		}
	
	Hockey_Message.innerText = "";
	puck_x = 16;
	puck_y = 16 + Math.floor (224 * Math.random ());
	puck_dx = 4 + score_high;
	puck_dy = 2 - Math.floor (5 * Math.random ());
	Speed.innerText = puck_dx;
	Puck_Move ();
	}

/***************************************************************************

***************************************************************************/
function Puck_Move () 
	{
	var string;
	var x;
	var y;

	puck_x += puck_dx;
	puck_y += puck_dy;

	// asume nothing happened
	string = "";

	// When we encounter left wall
	if (puck_x <= 16)
		{

		// Where was puck at the wall.
		x = (16 - puck_x) / -puck_dx;
		y = puck_y - Math.round (x * puck_dy);

		// if we don't make the goal bounce
		if ((112 < y) && (128 > y))
			{
			++score_high;
			Score_High.innerText = score_high;
			string = "You made the goal!";
			}
		else
			{
			puck_x = 16;
			puck_y = y;
			puck_dx = - puck_dx;
			}
		}

	// When we encounter foul line
	else if (puck_x >= 512)
		{

		// Where was puck at the foul line.
		x = (puck_x - 512) / puck_dx;
		puck_y = puck_y - Math.round (x * puck_dy);
		dy = mouse_y - puck_y;

		// If pointer makes contact bounce off the pointer
		if ((dy >= -1) && (dy <= 32))
			{
			puck_x = 512;
			if (puck_dx < 16)
				++puck_dx;
			Speed.innerText = puck_dx;
			puck_dx = - puck_dx;
			puck_dy += 2 - dy / 8;
			}
		else
			{
			++score_miss;
			Score_Miss.innerText = score_miss;
			string = "Strike " + score_miss + "!";
			if (score_miss > 2)
				{
				string += " You're out!";

				Scores_Update ();

				score_high = -1;
				}
			}
		}

	// When we encounter the side walls
	else if ((puck_y >= 224) || (puck_y <= 16))
		{
		puck_dy = - puck_dy;
		if (puck_y >= 224)
			puck_y = 224;
		else 
			puck_y = 16;
		}

	Sprite_Move (Hockey, Puck, puck_x, puck_y)

	if ("" == string)
		{
		if (0 == timer_id)
			timer_id = setInterval ("Puck_Move ()", 30);
		}
	else
		{
		if (0 != timer_id)
			clearInterval (timer_id);
		timer_id = 0;
		puck_dx = 0;
		if (score_high < 0)
			Hockey_Message.innerText = string + " Click to start a new game.";
		else
			Hockey_Message.innerText = string + " Click to restart the puck.";
		}
	}

/***************************************************************************

***************************************************************************/
function Debug_Object (object) 
	{
	document.write ('<P>Debug_Object ' + object);
	for (var i in eval(object))
		{      
		document.write ('<BR>' + object + "." + i + " = " + eval (object)[i]);
		}
	}