Feature: Background graphics

[KristofferStrube]

It seems sensible that it should be possible to add some background graphics/shapes to either serve as context for what is being edited or to give an idea of the zoom level/placement of the viewport.

This can be implemented in many ways, so I will start off by describing some simple cases and then later try to come up with an implementation that can support these cases.

• Grid: It would be nice to have a grid layout on the whole-number coordinates so that the user can relate the size of their shapes to this and align different parts of shapes to each other more easily. A problem with this is that it can be rather heavy to render many shapes in the background that will move a lot when the viewport moves.
• Static Shape: If the goal for using the editor is to sketch over something, then having a set of shapes that can't be selected, which are placed in the background, would be nice.

For both cases, the background shapes/grid would need to be transformed according to where the viewport is, so we can't simply place some static SVG/HTML in the background.

Before specifying any solution further, I would love to get feedback from the library users to see what concrete cases you have.

[nedimm]

At the moment I do have an use case where Static Shape is needed, exactly as you said, to sketch over something. Regarding the "Grid" use case, it would be nice to have, but I don't have such an use case at the moment. What I could not find until now are commands to align shapes toward the "canvas" or other shapes on the page.

[czaban]

It will be usefull for adding zones over security camera view - without adding the snapshot in background you have no idea where to put the polygon.