I want to make the snapping guidelines visible like those in Photoshop for the Krita Digital Art Software. Does Krita have a settings option that I could make use of, if not how can I write an external python script which will enable me to do so?
I have Krita 4.1.5 . Orthogonal and extension snapping guidelines are implemented there. Enable the snappings in the View > Snap To -menu. In the next image you see the guideline for extension snapping:
They work only with vector shapes. If I have a bitmap shape in a pixel layer, it's treated as whole layer. Its centerpoint can snap to guides, to image area horizontal and vertical center and to edges. But it doesn't see anything of the bitmap content of other pixel layers to snap. If I have a line in pixel layer, Krita doesn't calculate it's a line. It's only some pattern and the centerpoint of its layer is the only meaningful point that can snap.
How to program new functionality is unfortunately beyond my knowledge and the purpose of this site. You should join other programmers who have underhood knowledge of Krita.