One of the things that GIMP badly needs is a vectorial tool for drawing lines and arrows. This also would make sense as a first usable implementation of vector layers.

Here is how I think it could be structured:

1) For UI, there should be a GimpLineTool interface, modeled after GimpRectangleTool, but much simpler because it only needs to be able to move the two ends, rather than any of 8 possible corners or edges. This could be created by cloning GimpRectangleTool and then simplifying, or from scratch. It would only be an interface, not a tool in itself.

2) The interface would then be used in a GimpLineShapeTool (GimpArrowTool?), which would create a vector layer containing a single line segment, allowing options to be specified for rendering style and arrows on the ends. This would be an actual tool, accessible from the toolbox.

I mention this not because I want to do it myself (I don't particularly), but because I think it makes a good roadmap target, and one that might be interesting to active developers. Martin, I think, would be capable of setting up GimpLineTool, and it would give him something more creative to do in addition to fixing bugs in GimpRectangleTool (which is also important, of course, but not so exciting). For Henk, setting up GimpLineShapeTool (or whatever it is called) might give a target that is both extremely useful and an excellent start toward a full-fledged vector layer capability, without getting into all the complexities of arbitrary shapes.

-- Bill

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As GIMP moves toward vector layers and layer groups, it will more and more need a capability for "vector selection" -- that is, for the kind of selection capability found in vector graphics programs like Inkscape, whose target is a set of objects rather than a spatial region -- a "vector selection" as opposed to the "raster selection" that GIMP currently uses.

Actually, GIMP already has such a capability to some degree, in the "linking" mechanism, but it is too hard to use. I have some suggestions for improvement, which I would like to work on for GIMP 2.6 if it is okay. Here are my thoughts:

1) With two kinds of selection, there is no way to completely avoid confusing users. Probably the best thing to do is to keep calling the vector selection "linking". The only real problem with this is that the same thing is always called "selection" in vector graphics programs, but I think it is better to face this than to use the same word for two quite different things.

2) We need a "linking tool": a tool to allow objects/layers to be linked by mouse-clicking or rubber-banding. The UI for this already exists, in the Alignment Tool. In fact, that's actually all that the UI for the Alignment Tool does; the only change needed would be that, instead of the tool maintaining an internal list of the items that are selected, it would "link" them.

3) If the Alignment Tool is converted to a Linking Tool (with toolbox symbol an arrow pointing to the upper left), then no Alignment Tool is needed -- the functionality can be moved into a dialog, or pair of dialogs, accessible as Edit->Align or Edit->Distribute. The dialogs would operate on the set of objects that are linked.

4) Linked objects should be marked when the canvas is drawn, by putting small filled-rectangles at their corners, as is done in other vector-graphics programs.

5) Possibly the "chain" symbol in the Layers/Paths dialogs should be replaced by an arrow symbol.

6) The dialog in the Alignment Tool is modeled after the one in Inkscape, but has some differences. It could in principle be made virtually identical, even to the extent of using the same icons. There are a couple of things that Inkscape allows that GIMP wouldn't currently support, including (a) aligning the baselines of text layers, and (b) aligning "anchor" points of vector objects. I would welcome discussion of the pros and cons with somebody who is familiar with the Inkscape functionality.

7) There is a problem with paths (i.e., "Vectors") as currently implemented: the offsets and dimensions obtained using the gimp_item_get_foo() calls are not meaningful. This needs to be fixed to make a linking tool work properly, and really ought to be fixed in any case.

This is a sketch: I can spell out all the details in a more appropriate place. Although this may look like a long list of objectives, everything in it is actually simple to do (all the hard work was done in creating the alignment tool); and none of it creates much risk of breaking things that are deep and critical, as far as I can see.

-- Bill

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From: Sven Neumann

I don't see GIMP moving towards vector layers, at least not for 2.6. Layer groups are also not on the near-term roadmap. Perhaps we can target them for 2.8 but that remains to be seen.

Oh well, consider my suggestions as early contributions to the 2.8 roadmapping process, then.

-- Bill

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