Phaser3 9-slice Plugin
This is built for Phaser v3 and was inspired by the fantastic v2/CE versioncontributed by AleBlesAleBles. Find it at @orange-games/phaser-ninesliceorange.
What is 9-slice scaling?
tl;dr: See a demodemo-url! 9-slice scaling is a technique to deform a 2D texture allowing it to be scaled without deforming the corners. Usually this is done to retain the shape or embelishments on the corners. Wikipedia has a good descriptionwiki. But it's pretty easy to show an example:
Requirements
- phaser3-nineslice version >= 0.4.0 require Phaser >= 3.12.
- phaser3-nineslice versions 0.3.x require Phaser >= 3.10.
Getting the plugin: Directly including it.
Includenineslice.js
in your project:
```html
```
I used this method in the demo. The source is included in this
repository.
Getting the plugin: npm
and yarn
npm:
npm install phaser3-nineslice --save
yarn:
yarn add phaser3-nineslice
```
Usage
Once you've included the plugin through one of the methods above there are two final steps to make use of it in your project:- Enable the Plugin in your
Game
config:
```javascript
// Assuming you use use ES6 imports...
import { Plugin as NineSlicePlugin } from 'phaser3-nineslice'
import { Scene1 } from './scene'
let phaserConfig = {
type: Phaser.AUTO,
parent: 'phaser-display',
backgroundColor: '0x9a9a9a',
width: 800,
height: 600,
plugins: {
Game
config:global: [ NineSlicePlugin.DefaultCfg ],
},
scene: Scene1 ,
}
new Phaser.Game(phaserConfig)
```
You likely won't need to mess with it but, internally, DefaultCfg
is
defined as { key: 'NineSlice', plugin: NineSlicePlugin, start: true }
but any key
can be used if you need to change it.
- Use the plugin to make 9-sliced objects!
The easiest way to construct a new sliced object is to use the new
GameObjectFactory
method (this.add.nineslice
) or new GameObjectCreator
method (this.make.nineslice
).
```javascript
create() {
this.dlg = this.add.nineslice(
110, 110, // this is the starting x/y location
340, 240, // the width and height of your object
'dlgLarge', // a key to an already loaded image
88, // the width and height to offset for a corner slice
24 // (optional) pixels to offset when computing the safe usage area
)
// ... additional scene creation code
}
```
Examining the resulting object added to your scene we can observe how the numbers
above are used.

Phaser.Geom.Retangle
via .getUsableBounds
method on the 9 slice object. Whenever the object changes x/y position or
is resized an event NineSlice.EVENT.UPDATE_SAFE_BOUNDS
is emitted;
code refemitref.
Spritesheets and Texture Atlases
The fifth paramater is used to specify the texture and can be provided as a
string to use a loaded texture or an object with the structure
```javascript
{
key: string,
frame: string | number,
}
```
if you would like to specify a frame within a spritesheet or atlas indicated
by key
.
Non-uniform corner slices
If your texture doesn't have uniform corners you can define the width and height
offsets of each independently using a slightly more complicated format. The same
true for the safe usage area.
```javascript
this.dlg = this.add.nineslice(
110, 110, 340, 240, 'kenny',
35, 15, 15, 15,
)
```
This results in the following texture slicing:

[ topRightBottomLeft ]
| The first (only) element is used as the value for all four sides
2 | [ topBottom, leftRight ]
| The first element is used for the top and bottom, the second element is used as the for the left and right
3 | [ top, rightLeft, bottom ]
| The first element is used for the top, second is used for the right and left, and the third element is used for the bottom
4 | [ top, right, bottom, left ]
| Each element is assigned to a specific side
In addition to switching to an array to define the pixel offsets for the corners
our example also left out the safe area usage. In this case will be derived from
the four corner offsets as seen above by the green area. If an array is used
instead of a number it is expanded in the same way as
Resizing your 9 Slice
Directly setting the .width
and .height
attributes will cause scaling issues
(#1iss1). If you wish to change the object's size you should use .resize
:
```javascript
this.dlg = this.add.nineslice(
110, 110, 340, 240, 'kenny',
[35, 15, 15, 15],
)
// ...
this.dlg.resize(400, 400)
```
If the call to resize would result in the safe area having an area of less than
0 or the corners to overlap then it will only reduce its size to that point.
Direct Configuration
In addition to the factory/creator methods you can construct a NineSlice directly:
```javascript
this.dlg = new NineSlice.NineSlice(
scene, // the parent scene of this objects
sliceConfig, // configures the source texture and layout of slice relative to it
positionConfig, // specifies location and dimensions of the constructed object
)
```
For details about the structure of the config objects referenced above see
NineSliceConfig
and PositionConfig
in types.js
.
They may also be passed to .add
and .make
:
```javascript
this.make.nineslice(sliceConfig, positionConfig)
```
Summary
Valid arguments to .add.nineslice
and .make.nineslice
are:
```
Arguments =
| (NineSliceConfig, PositionConfig)
| (x: number,
y: number,
w: number,
h: number,
source: FrameSelection,
corner: OffsetConfig,
safeArea: OffsetConfig | null)
FrameSelection =
| key: string
| {
key: string,
frame: number | string,
}
OffsetConfig =
| number
| topRightBottomLeft: number
| topBottom: number, rightLeft: number,
| top: number, rightLeft: number, bottom: number,
| top: number, right: number, bottom: number, left: number
```