A max rectangle 2d bin packer for packing glyphs or images into multiple sprite-sheet/atlas
npm install maxrects-packer
!npm
!NPM Type Definitions
A simple max rectangle 2d bin packing algorithm for packing glyphs or images into multiple sprite-sheet/atlas. Minimalist with no module dependency.
This is a evolved version of Multi-Bin-Packer with much efficient packing algorithm. All interfaces and methods are inherited so no tweaks needed in your current code except module name.
It differs from the long list of similar packages by its packing approach: Instead of creating one output bin with a minimum size this package is trying to create a minimum number of bins under a certain size. This avoids problems with single massive image files that are not browser-friendly. This can be especially useful for WebGL games where the GPU will benefit from spritesheets close to power-of-2 sizes.
And you can also save/load to reuse packer to add new sprites. (Below is a demo atlas packed with two difference bitmap fonts)
``bash`
npm install maxrects-packer --save
Note: Since version 2.0.0 Max Rects Packer is rewritten in typescript and change the import method from old require("maxrects-packer") to require("maxrects-packer").MaxRectsPacker or more fashioned import statement.
Note: Since version 2.1.0 packer can be fed with any object with width & height members, no need to follow { width: number, height: number, data: any } pattern, if you are using typescript, that also mean any class extending MaxRectsPacker.IRectangle
Note: *Since version 2.1.0 Rectangle class constructor API is changed from new Rectangle(x, y, width, height, rotated) to new Rectangle(width, height, x, y, rotated), cos most cases you only need to feed w/h and omit the rest like new Rectangle(100, 100) and left x,y,rotated to default value.
`javascript
let MaxRectsPacker = require("maxrects-packer").MaxRectsPacker;
const options = {
smart: true,
pot: true,
square: false,
allowRotation: true,
tag: false,
border: 5
}; // Set packing options
let packer = new MaxRectsPacker(1024, 1024, 2, options); // width, height, padding, options
let input = [ // any object with width & height is OK since v2.1.0
{width: 600, height: 20, name: "tree", foo: "bar"},
{width: 600, height: 20, name: "flower"},
{width: 2000, height: 2000, name: "oversized background", {frameWidth: 500, frameHeight: 500}},
{width: 1000, height: 1000, name: "background", color: 0x000000ff},
{width: 1000, height: 1000, name: "overlay", allowRotation: true}
];
packer.addArray(input); // Start packing with input array
packer.next(); // Start a new packer bin
packer.addArray(input.slice(2)); // Adding to the new bin
packer.bins.forEach(bin => {
console.log(bin.rects);
});
// Reuse packer
let bins = packer.save();
packer.load(bins);
packer.addArray(input);
`
`bash`
npm test
Note: maxrects-packer requires node >= 4.0.0
#### `new MaxRectsPacker(maxWidth, maxHeight[, padding, options])`
Creates a new Packer. maxWidth and maxHeight are passed on to all bins. If `padding` is supplied all rects will be kept at least `padding` pixels apart.
- options.smart packing with smallest possible size. (default is true)options.pot
- bin size round up to smallest power of 2. (default is true)options.square
- bin size shall alway be square. (default is false)options.allowRotation
- allow 90-degree rotation while packing. (default is false)options.tag
- allow tag based group packing. (default is false)options.exclusiveTag
- tagged rects will have dependent bin, if set to false, packer will try to put tag rects into the same bin (default is true)options.border
- atlas edge spacing (default is 0)options.logic
- how to fill the rects. There are three options: 0 (max area), 1 (max edge), 2 (fillWidth). Default is 1 (max edge)
#### `packer.add(width, height, data)` +1 overload
Adds a rect to an existing bin or creates a new one to accommodate it. `data` can be anything, it will be stored along with the position data of each rect.
#### `packer.add({width: number, height: number, ... })` +1 overload
Adds a rect to an existing bin or creates a new one to accommodate it. Accept any object with width & height. If you are using typescript, that means any class extends MaxRectsPacker.IRectangle
#### `packer.addArray([{width: number, height: number, ...}, ...])`
Adds multiple rects. Since the input is automatically sorted before adding this approach usually leads to fewer bins created than separate calls to `.add()`
#### `packer.repack(quick: boolean = true)`
Repack all elements inside bins. If quick == true, only bins with dirty flag will be repacked. If false is passed, all rects inside this packer will be re-sort and repacked, might result different bin number. Slower but high packing efficiency.
#### `packer.next()`
Stop adding new element to the current bin and return a new bin. After calling next() all elements will no longer added to previous bins.
#### `let bins = packer.save()`
Save current bins settings and free area to an Array of objects for later use. Better to JSON.stringify(bins) and store in file.
#### `packer.load(bins)`
Restore previous saved let bins = JSON.parse(fs.readFileSync(savedFile, 'utf8')); settings and overwrite current one. Continue packing and previous packed area will not be overlapped.
#### `packer.bins`
Array of bins. Every bin has a `width` and `height` parameter as well as an array `rects`.
#### `packer.bins[n].rects`
Array of rects for a specific bin. Every rect has `x`, `y`, `width`, `height`, `rot` and `data`. In case of an rect exceeding `maxWidth`/`maxHeight` there will also be an `oversized` flag set to `true`.
If options.allowRotation is set to true, packer will attempt to do an extra test in findNode() on rotated Rectangle. If the rotated one gives the best score, the given Rectangle will be rotated in the Rectangle.rot set to true.
If options.tag is set to true, packer will check if the input object has tag: string property, all input with same tag will be packed in the same bin.
Normally all bins are of equal size or smaller than `maxWidth`/`maxHeight`. If a rect is added that individually does not fit into those constraints a special bin will be created. This bin will only contain a single rect with a special "oversized" flag. This can be handled further on in the chain by displaying an error/warning or by simply ignoring it.
options.logic allows to change the method on how the algorithm selects the free spaces. There are three options:
{option.logic = 0} Logic is MAX_AREA, selects the free space with the smallest loss of area.
{option.logic = 1} Logic is MAX_EDGE, is default and selects the free space with the smallest loss of either width or height.
{option.logic = 2} Logic is FILL_WIDTH, fills the complete width first before placing elements in next row. To get the used height bin.height only gives correct values with options: {pot: false, square: false}. Best results also with option.allowRotation = true`
Use Max Rectangle Algorithm for packing, same as famous Texture Packer