Instead of having 2 ways of setting the point it would be much cleaner to do:

```js
point = point || new PIXI.Point();

point.x = a11 * id * global.x + -a01 * id * global.y + (a12 * a01 - a02 * a11) * id;
point.y = a00 * id * global.y + -a10 * id * global.x + (-a12 * a00 + a02 * a10) * id;

return point;
```

Which would handle both cases, and remove duplicated code and a conditional.