Limit mask using coordinates instead of another object

How do I...?
#1

How can I get the width and height of an object mask?

This mask → objects[0].getRendererObject().mask

I want to limit it without using another object as mask.

Example:

I use some code (that I don’t know yet) to get the width and height of the mask above, and it is 100px/100px (because the object is 100px width and height)

Then I want to make the mask 80px tall, making it not render 20 pixels of the bottom of the object.

#2

I tried this code:

objects.forEach(instance => {
const renderer = instance.getRendererObject();
const maskY = renderer.y;
console.log('Old maskY: ',maskY);
renderer.y = maskY - 2000;
console.log('New maskY: ',renderer.y);
});

It indeed logs the changes in the mask y in the console, but nothing seems to visually change in the preview.