Phaser API Documentation

Description:

A Nine Slice Game Object allows you to display a texture-based object that can be stretched both horizontally and vertically, but that retains fixed-sized corners. The dimensions of the corners are set via the parameters to this class.

This is extremely useful for UI and button like elements, where you need them to expand to accommodate the content without distorting the texture.

The texture you provide for this Game Object should be based on the following layout structure:

     A                          B
   +---+----------------------+---+
 C | 1 |          2           | 3 |
   +---+----------------------+---+
   |   |                      |   |
   | 4 |          5           | 6 |
   |   |                      |   |
   +---+----------------------+---+
 D | 7 |          8           | 9 |
   +---+----------------------+---+

When changing this objects width and / or height:

areas 1, 3, 7 and 9 (the corners) will remain unscaled
areas 2 and 8 will be stretched horizontally only
areas 4 and 6 will be stretched vertically only
area 5 will be stretched both horizontally and vertically

You can also create a 3 slice Game Object:

This works in a similar way, except you can only stretch it horizontally. Therefore, it requires less configuration:

     A                          B
   +---+----------------------+---+
   |   |                      |   |
 C | 1 |          2           | 3 |
   |   |                      |   |
   +---+----------------------+---+

When changing this objects width (you cannot change its height)

areas 1 and 3 will remain unscaled
area 2 will be stretched horizontally

The above configuration concept is adapted from the Pixi NineSlicePlane.

To specify a 3 slice object instead of a 9 slice you should only provide the leftWidth and rightWidth parameters. To create a 9 slice you must supply all parameters.

The minimum width this Game Object can be is the total of leftWidth + rightWidth. The minimum height this Game Object can be is the total of topHeight + bottomHeight. If you need to display this object at a smaller size, you can scale it.

In terms of performance, using a 3 slice Game Object is the equivalent of having 3 Sprites in a row. Using a 9 slice Game Object is the equivalent of having 9 Sprites in a row. The vertices of this object are all batched together and can co-exist with other Sprites and graphics on the display list, without incurring any additional overhead.

As of Phaser 3.60 this Game Object is WebGL only.