Classe em Javascript entender

[Alan Castelan]

Tenho uma classe javascript mas não estou entendendo ela, segue o codigo abaixo

preciso entende-la para reescrever o codigo em delphi

eu não estou entendendo o que acontece em Fit, e o que é a variavel block.fit onde ela é declarada ?

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

Best results occur when the input blocks are sorted by height, or even better

when sorted by max(width,height).

Inputs:

------

w: width of target rectangle

h: height of target rectangle

blocks: array of any objects that have .w and .h attributes

Outputs:

-------

marks each block that fits with a .fit attribute pointing to a

node with .x and .y coordinates

Example:

-------

var blocks = [

{ w: 100, h: 100 },

{ w: 100, h: 100 },

{ w: 80, h: 80 },

{ w: 80, h: 80 },

etc

etc

];

var packer = new Packer(500, 500);

packer.fit(blocks);

for(var n = 0 ; n < blocks.length ; n++) {

var block = blocks[n];

if (block.fit) {

Draw(block.fit.x, block.fit.y, block.w, block.h);

}

}

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

Packer = function(w, h) {

this.init(w, h);

};

Packer.prototype = {

init: function(w, h) {

this.root = { x: 0, y: 0, w: w, h: h };

},

fit: function(blocks) {

var n, node, block;

for (n = 0; n < blocks.length; n++) {

block = blocks[n];

if (node = this.findNode(this.root, block.w, block.h)){

block.fit = this.splitNode(node, block.w, block.h);

}

}

},

findNode: function(root, w, h) {

if (root.used)

return this.findNode(root.right, w, h) || this.findNode(root.down, w, h);

else if ((w <= root.w) && (h <= root.h))

return root;

else

return null;

},

splitNode: function(node, w, h) {

node.used = true;

node.down = { x: node.x, y: node.y + h, w: node.w, h: node.h - h };

node.right = { x: node.x + w, y: node.y, w: node.w - w, h: h };

return node;

}

}