Particles.Arcade.Emitter#align()

This method iterates through all children in the Group (regardless if they are visible or exist)
and then changes their position so they are arranged in a Grid formation. Children must have
the alignTo method in order to be positioned by this call. All default Phaser Game Objects have
this.

The grid dimensions are determined by the first four arguments. The width and height arguments
relate to the width and height of the grid respectively.

For example if the Group had 100 children in it:

Group.align(10, 10, 32, 32)

This will align all of the children into a grid formation of 10x10, using 32 pixels per
grid cell. If you want a wider grid, you could do:

Group.align(25, 4, 32, 32)

This will align the children into a grid of 25x4, again using 32 pixels per grid cell.

You can choose to set either the width or height value to -1. Doing so tells the method
to keep on aligning children until there are no children left. For example if this Group had
48 children in it, the following:

Group.align(-1, 8, 32, 32)

... will align the children so that there are 8 children vertically (the second argument),
and each row will contain 6 sprites, except the last one, which will contain 5 (totaling 48)

You can also do:

Group.align(10, -1, 32, 32)

In this case it will create a grid 10 wide, and as tall as it needs to be in order to fit
all of the children in.

The position property allows you to control where in each grid cell the child is positioned.
This is a constant and can be one of Phaser.TOP_LEFT (default), Phaser.TOP_CENTER,
Phaser.TOP_RIGHT, Phaser.LEFT_CENTER, Phaser.CENTER, Phaser.RIGHT_CENTER,
Phaser.BOTTOM_LEFT, Phaser.BOTTOM_CENTER or Phaser.BOTTOM_RIGHT.

The final argument; offset lets you start the alignment from a specific child index.