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

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

  function random(a, b) {
  	return Math.random() - 0.5;
  }

• w

  function w(a, b) {
  	return b.w - a.w;
  }

• h

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

• a

  function a(_a, b) {
  	return b.area - _a.area;
  }

• max

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

• min

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

• height

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

• width

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

• area

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

• maxside

  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.