/* This notice must be untouched at all times.

jsgraphics.js    v. 1.42
The latest version is available at
http://www.walterzorn.com
or http://www.devira.com
or http://www.walterzorn.de

Copyright (c) 2002-2003 Walter Zorn. All rights reserved.
Created 3. 11. 2002 by Walter Zorn <walter@kreuzotter.de>
Last modified: 28. 2. 2003

High Performance JavaScript Graphics Library.
Provides methods to draw lines, rectangles, ellipses, polygons, text
and to fill rectangles and ellipses.
NOTE: Operations, functions and branching have rather been optimized
to efficiency and speed than to shortness of source code.

This program is free software;
you can redistribute it and/or modify it under the terms of the
GNU General Public License as published by the Free Software Foundation;
either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License
at http://www.gnu.org/copyleft/gpl.html for more details.
*/


var jg_ihtm, jg_ie, jg_dom,
jg_n4 = (navigator.appName + parseInt(navigator.appVersion) == 'Netscape4' && document.layers);

function chkDHTM(x, i)
{
	jg_ie = (x && typeof x.insertAdjacentHTML != "undefined");
	jg_dom = (x && !jg_ie &&
		typeof x.appendChild != "undefined" &&
		typeof document.createRange != "undefined" &&
		typeof (i = document.createRange()).setStartBefore != "undefined" &&
		typeof i.createContextualFragment != "undefined");
	jg_ihtm = (!jg_ie && !jg_dom &&	x && typeof x.innerHTML != "undefined");
}


function pntDoc()
{
	document.write(this.htm);
	this.htm = '';
}


function pntCnv()
{
	if (!this.dhtm);
	else if (jg_dom)
	{
		var x = document.createRange();
		x.setStartBefore(this.cnv);
		x = x.createContextualFragment(this.htm);
		this.cnv.appendChild(x);
	}
	else if (jg_ie)
		this.cnv.insertAdjacentHTML("BeforeEnd", this.htm);
	else this.cnv.innerHTML += this.htm;
	this.htm = '';
}


function mkDiv(x, y, w, h)
{
	this.htm += '<div style="position:absolute;'+
		'left:' + x + 'px;'+
		'top:' + y + 'px;'+
		'width:' + w + 'px;'+
		'height:' + h + 'px;'+
		'clip:rect(0,'+w+'px,'+h+'px,0);'+
		'overflow:hidden;background-color:' + this.color + ';'+
		'"><\/div>';
}


function mkLyr(x, y, w, h)
{
	this.htm += '<layer '+
		'left="' + x + '" '+
		'top="' + y + '" '+
		'width="' + w + '" '+
		'height="' + h + '" '+
		'bgcolor="' + this.color + '"><\/layer>';
}


function mkLbl(txt, x, y)
{
	this.htm += '<div style="position:absolute;white-space:nowrap;'+
		'left:' + x + 'px;'+
		'top:' + y + 'px;'+
		'font-family:' +  this.ftFam + ';'+
		'font-size:' + this.ftSz + ';'+
		'color:' + this.color + ';' + this.ftSty + '">'+
		txt +
		'<\/div>';
}


function mkLine(x1, y1, x2, y2)
{
	if (x1>x2)
	{
		var _x2 = x2;
		var _y2 = y2;
		x2 = x1;
		y2 = y1;
		x1 = _x2;
		y1 = _y2;
	}
	var dx = x2-x1, dy = Math.abs(y2-y1),
	x = x1, y = y1,
	yIncr = (y1>y2)? -1 : 1;
	if (dx>=dy)
	{
		var pr = dy<<1,
		pru = pr - (dx<<1),
		p = pr-dx,
		ox = x;
		while ((dx--)>=0)
		{
			if (p>0)
			{
				this.mkDiv(ox, y, x-ox+1, 1);
				x++;
				y += yIncr;
				p += pru;
				ox = x;
			}
			else
			{
				x++;
				p += pr;
			}
		}
		this.mkDiv(ox, y, x2-ox+1, 1);
	}
	else
	{
		var pr = dx<<1,
		pru = pr - (dy<<1),
		p = pr-dy,
		oy = y;
		if (y2<=y1)
		{
			while ((dy--)>=0)
			{
				if (p>0)
				{
					this.mkDiv(x, y, 1, oy-y+1);
					x++;
					y += yIncr;
					p += pru;
					oy = y;
				}
				else
				{
					y += yIncr;
					p += pr;
				}
			}
			this.mkDiv(x2, y2, 1, oy-y2+1);
		}
		else
		{
			while ((dy--)>=0)
			{
				if (p>0)
				{
					this.mkDiv(x, oy, 1, y-oy+1);
					x++;
					y += yIncr;
					p += pru;
					oy = y;
				}
				else
				{
					y += yIncr;
					p += pr;
				}
			}
			this.mkDiv(x2, oy, 1, y2-oy+1);
		}
	}
}


function mkOv(left, top, width, height, fill)
{
	var a = width>>1, b = height>>1,
	wod = width&1, hod = height&1,
	cx = left+a, cy = top+b,
	x = 0, y = b,
	ox = 0, oy = b,
	h,
	a2 = (a*a)<<1, b2 = (b*b)<<1,
	st = (a2>>1)*(1-(b<<1)) + b2,
	tt = (b2>>1) - a2*((b<<1)-1);
	if (fill)
	{
		do
		{
			if (st<0)
			{
				st += b2*((x<<1)+3);
				tt += (b2<<1)*(x+1);
				x++;
			}
			else if (tt<0)
			{
				st += b2*((x<<1)+3) - (a2<<1)*(y-1);
				tt += (b2<<1)*(x+1) - a2*((y<<1)-3);
				x++;
				y--;
				h = oy-y;
				this.mkOvQdsFill(cx, cy, -x+1, -oy, oy-h+1+hod, ((x-1)<<1)+1+wod, h);
				ox = x;
				oy = y;
			}
			else
			{
				st -= (a2<<1)*(y-1);
				tt -= a2*((y<<1)-3);
				y--;
			}
		}
		while (y>0);
		this.mkDiv(cx-a, cy-oy, width+1, (oy<<1)+1+hod);
	}
	else
	{
		var w;
		do
		{
			if (st<0)
			{
				st += b2*((x<<1)+3);
				tt += (b2<<1)*(x+1);
				x++;
			}
			else if (tt<0)
			{
				st += b2*((x<<1)+3) - (a2<<1)*(y-1);
				tt += (b2<<1)*(x+1) - a2*((y<<1)-3);
				x++;
				y--;
				w = x-ox;
				h = oy-y;
				if (w&2 && h&2)
				{
					var dx, dy;
					if (oy!=b)
					{
						dx = 0;
						dy = 1;
						this.mkOvQds(cx, cy, -x+1, x-1+wod, -oy, oy+hod, 1, 1);
					}
					else
					{
						dx = 1;
						dy = 0;
					}
					this.mkOvQds(cx, cy, -x+2, x-2+wod, -oy-dy, oy+dy+hod, 1, 1);
					this.mkOvQds(cx, cy, -x+dx, x-dx+wod, -y-1, y+1, 1, 1);
				}
				else this.mkOvQds(cx, cy, -x+1, ox+wod, -oy, oy-h+1+hod, w, h);
				ox = x;
				oy = y;
			}
			else
			{
				st -= (a2<<1)*(y-1);
				tt -= a2*((y<<1)-3);
				y--;
			}
		}
		while (y>0);
		this.mkDiv(cx-a, cy-oy, 1, (oy<<1)+1+hod);
		this.mkDiv(cx+a+wod, cy-oy, 1, (oy<<1)+1+hod);
	}
}


function jsGraphicsFt()
{
	this.PLAIN = '';
	this.BOLD = 'font-weight:bold;';
	this.ITALIC = 'font-style:italic;';
	this.ITALIC_BOLD = this.ITALIC + this.BOLD;
	this.BOLD_ITALIC = this.ITALIC_BOLD;
}
var Font = new jsGraphicsFt();


function jsGraphics(id)
{
	this.setColor = new Function('color', 'this.color = color;');

	this.setFont = function(fam, sz, sty)
	{
		this.ftFam = fam;
		this.ftSz = sz;
		if (sty) this.ftSty = sty;
	}

	this.drawLine = function(x1, y1, x2, y2)
	{
		this.mkLine(x1, y1, x2, y2);
	}

	this.drawPolyline = function(x, y)
	{
		var z = 0; while (z < x.length-1)
			this.mkLine(x[z], y[z], x[++z], y[z]);
	}

	this.drawPolyLine = this.drawPolyline;

	this.drawRect = function(x, y, w, h)
	{
		this.mkDiv(x, y, w, 1);
		this.mkDiv(x+w, y, 1, h);
		this.mkDiv(x, y+h, w+1, 1);
		this.mkDiv(x, y, 1, h);
	}

	this.fillRect = function(x, y, w, h)
	{
		this.mkDiv(x, y, w, h);
	}

	this.drawPolygon = function(x, y)
	{
		this.drawPolyline(x, y);
		this.mkLine(x[x.length-1], y[x.length-1], x[0], y[0]);
	}

	this.drawEllipse = function(x, y, w, h)
	{
		this.mkOv(x, y, w, h, false);
	}

	this.drawOval = this.drawEllipse;

	this.fillEllipse = function(x, y, w, h)
	{
		this.mkOv(x, y, w-1, h-1, true)
	}

	this.fillOval = this.fillEllipse;

	this.drawString = mkLbl;

	this.clear = function()
	{
		this.htm = "";
		if (!this.dhtm) return;
		this.cnv.innerHTML = this.defhtm;
	}

	this.mkDiv = jg_n4? mkLyr : mkDiv;

	this.mkLine = mkLine;

	this.mkOv = mkOv;

	this.mkOvQdsFill = function(cx, cy, xl, yt, yb, w, h)
	{
		xl += cx;
		this.mkDiv(xl, cy+yt, w, h);
		this.mkDiv(xl, cy+yb, w, h);
	}

	this.mkOvQds = function(cx, cy, xl, xr, yt, yb, w, h)
	{
		xr += cx;
		xl += cx;
		yt += cy;
		yb += cy;
		this.mkDiv(xr, yt, w, h);
		this.mkDiv(xr, yb, w, h);
		this.mkDiv(xl, yb, w, h);
		this.mkDiv(xl, yt, w, h);
	}

	this.color = '#000000';
	this.ftFam = 'verdana,geneva,helvetica,sans-serif';
	this.ftSz = String.fromCharCode(0x31, 0x32, 0x70, 0x78);
	this.ftSty = Font.PLAIN;
	this.htm = '';
	if (id == document) this.paint = pntDoc;
	else
	{
		this.paint = pntCnv;
		this.cnv = document.all? (document.all[id] || null)
			: document.getElementById? (document.getElementById(id) || null)
			: null;
		this.defhtm = (this.cnv && this.cnv.innerHTML)? this.cnv.innerHTML : '';
		if (!(jg_ie || jg_dom || jg_ihtm)) chkDHTM(this.cnv);
		this.dhtm = (this.cnv && (jg_ie || jg_dom || jg_ihtm));
	}
}