Adding Assistants (Incl. Perspective Tool)

[MorrowShore]

Its request inevitable, demand for the perspective tool has at last appeared.

This tool exists in Krita, and its implementation should not be too much hassle.

There are 1-point, 2-point, and 3-point perspectives.

Here are some assistants:

Source: https://ken26u.blog/drawing/krita/2020-10-10-162329/2020/10/10/

"Ideally, there should be the possibility of having multiple concurrent yet independent perspective guides, differentiated with their opacity or color."

Note that it is imperative for the perspective guide to be non-disruptive, and non-interactable during drawing.

Additional information: https://docs.krita.org/en/user_manual/painting_with_assistants.html