RandomDotMotion in square region

Is it possible to constrain the display of RandomDotMotion to a square region rather than a circular region? This question is not regarding the appearance of the dots themselves, but rather the area in which they are displayed.

I have come up with a rather clumsy method: use the zorder to cover the front of the dots with an image with a square hole

One problem of that approach is that you cannot control the number of dots displayed in each frame. It is better just to draw in a square from the beginning.

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If you download the package again, you will see a new adapter that does this, although I am not sure how useful it will be.
https://monkeylogic.nimh.nih.gov/docs_RuntimeFunctions.html#RectangularRDM

Regarding to how to use it, see the 'task\runtime v2\8 random dot motion' example. The code is updated for the demonstration.