jakes-gordon-growing-packer

jakes-gordon-growing-packer
==================



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A javascript binary tree based algorithm for 2d bin-packing

Purpose
-------

+ Creating a spritesheet generator

Install
-------

``
npm install jakes-gordon-growing-packer
`

How to use
----------

See first the Original algorithm README

`javascript

var GrowingPacker = require('jakes-gordon-growing-packer')

var packer = new GrowingPacker({
//sortMethod: a sort method or a valid sort method name, default to maxside

blocks: [
{ w: 100, h: 100 },
{ w: 100, h: 100 },
{ w: 80, h: 80 },
{ w: 80, h: 80 }
]
/ blocks is optional and can be passed directly to the pack method /
});

var pack = packer.pack();

// or

var packer = new GrowingPacker();
var pack = packer.pack([
{ w: 100, h: 100 },
{ w: 100, h: 100 },
{ w: 80, h: 80 },
{ w: 80, h: 80 }
]);

// then

console.log(pack.width, pack.height);

var rectangles = pack.rectangles(); //note that the rectangles method modify your original blocks array

for(var i = 0, imax = rectangles.length ; i < imax ; i++) {
var rect = rectangles[i];

//do something like :
//DrawRectangle(rect.x, rect.y, rect.w, rect.h);
}

`

Valid sort methods
------------------

+ random

`javascript
function random(a, b) {
return Math.random() - 0.5;
}
`
+ w

`javascript
function w(a, b) {
return b.w - a.w;
}
`
+ h

`javascript
function h(a, b) {
return b.h - a.h;
}
`
+ a

`javascript
function a(_a, b) {
return b.area - _a.area;
}
`
+ max

`javascript
function max(a, b) {
return Math.max(b.w, b.h) - Math.max(a.w, a.h);
}
`
+ min

`javascript
function min(a, b) {
return Math.min(b.w, b.h) - Math.min(a.w, a.h);
}
`
+ height

`javascript
function height(a, b) {
return msort(a, b, ['h', 'w']);
}
`
+ width

`javascript
function width(a, b) {
return msort(a, b, ['w', 'h']);
}
`
+ area

`javascript
function area(a, b) {
return msort(a, b, ['a', 'h', 'w']);
}
`
+ maxside

`javascript
function maxside(a, b) {
return msort(a, b, ['max', 'min', 'h', 'w']);
}
``

Credits
-------

The packing algorithm is from here

I just wrap it in a custom API (including the sort methods proposed by Jake Gordon ) and make it accesible via npm since that issue is still opened.