2d

gibney.org : Technology : Javascript : Repository : 2d

(Entry Nr. 39, by user 1 | edit)

ge_2d = 
{

getX: function(obj)
 {
  var curleft = 0;
  if (obj.offsetParent)
  {
   while (obj.offsetParent)
   {
    curleft += obj.offsetLeft
    obj = obj.offsetParent;
   }
  }
  else if (obj.x)
  curleft += obj.x;
  return curleft;
 },

getY: function(obj)
 {
  var curtop = 0;
  if (obj.offsetParent)
  {
   while (obj.offsetParent)
   {
    curtop += obj.offsetTop
    obj = obj.offsetParent;
   }
  }
  else if (obj.y) curtop += obj.y;
  return curtop;
 }

}

// Old Stuff. Dont use in new code: ---------------------------------------------------------------------------

var mg_BrowserIsIE = (document.all) ? 1 : 0;
var mg_BrowserIsNS = (document.layers) ? 1 : 0;

function mg_setElementClass(id,ClassName)
{
	document.getElementById(id).className=ClassName
}

function mg_setElementPosition(id,x,y)
{
 if (mg_BrowserIsIE)
 {
  var obj = eval(id+".style");
  obj.posLeft=x;
  obj.posTop =y;
 }
 else 
 if (mg_BrowserIsNS)
 {
  var obj = eval("document."+id);
  nspan.left=x;
  nspan.top =y;
 }
 else
 {
  document.getElementById(id).style.left=x;
  document.getElementById(id).style.top =y;
 }
}

function mg_getElementX(id)
{
	obj=document.getElementById(id);
	var curleft = 0;
	if (obj.offsetParent)
	{
		while (obj.offsetParent)
		{
			curleft += obj.offsetLeft
			obj = obj.offsetParent;
		}
	}
	else if (obj.x)
		curleft += obj.x;
	return curleft;
}

function mg_getElementY(id)
{
	obj=document.getElementById(id);
	
	var curtop = 0;
	if (obj.offsetParent)
	{
		while (obj.offsetParent)
		{
			curtop += obj.offsetTop
			obj = obj.offsetParent;
		}
	}
	else if (obj.y)
		curtop += obj.y;
	return curtop;

//return document.getElementById(id).offsetTop;
}

function mg_2d_Element(id,x,y,FollowAim)
{
	this.id=id;
	this.x=x;
	this.y=y;
	this.SpeedX=0;
	this.SpeedY=0;
	this.AimX=x;
	this.AimY=y;
	this.FollowAim=FollowAim;
	
	//document.getElementById(id).style.position="absolute";
	
	this.redraw = function()
	{
		mg_setElementPosition(this.id,this.x,this.y);
	}
	
	this.timeStep = function()
	{
		this.x+=this.SpeedX;
		this.y+=this.SpeedY;
		mg_setElementPosition(this.id,this.x,this.y);
		
		if (this.FollowAim)
		{
			DiffX=this.AimX-this.x;
			DiffY=this.AimY-this.y;
			this.SpeedX+=DiffX/100;
			this.SpeedY+=DiffY/100;
		}
		
		// velocity
		this.SpeedX*=0.9;
		this.SpeedY*=0.9;
		
	}
}

function mg_2d_Swarm(MyName)
{
 this.MyName=MyName;
 this.Elements=new Array();
 
 // addElement ------------------------------------------------------
 this.addElement=function(id,FollowAim)
 {
	pos_x=mg_getElementX(id);
	pos_y=mg_getElementY(id);
  
	this.Elements[id]=new mg_2d_Element(id,pos_x,pos_y,FollowAim);
	
  //document.write("added to swarm: "+id+"<br>");
 }
 // ------------------------------------------------------ addElement
 
	this.redraw=function()
	{
		for (i in this.Elements) this.Elements[i].redraw();
	}
 
 this.timeStep=function()
 {
  for (i in this.Elements) this.Elements[i].timeStep();
  timer=setTimeout(MyName+".timeStep()",10);
 }
 
 this.start=function()
 {
  timer=setTimeout(MyName+".timeStep()",10);
	for (i in this.Elements) document.getElementById(this.Elements[i].id).style.position="absolute"; 
 }
}

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