Please post links to screenshots and/or insights of this vector app. We must learn from others.
- About the only scriptable free-software vector graphics program.
- Bézier curves, rectangles and ellipses can be used as guides.
- Text along path, with choice between rotation or vertical skew of glyphs. (Inkscape has SVG text-on-path, which I think only allows rotation rather than skew.)
- Can blend between paths (morphing).
- Written mainly in Python.
- "Conical gradients" as well as the linear & radial gradients supported by SVG/Inkscape.
- Claims to support masking; I haven't looked at its interface. (I believe Inkscape honours masking/clipping directives in SVG files, but has no user interface for this unless you count the boolean operations.)
screenshot showing layer dialog has four toggle buttons for each layer: screen visibility; printing visibility (probably including visibility in exported bitmaps); lockedness; and a "show outline only" option. Each layer can have its own colour used when show-out-line-only is on.
There is a separate layer for guide objects/lines. The layer's show-outline-only option is always on, the print option is always off, while the visibility and lockedness options remain togglable.
The grid has its own layer too, unselectable, but useful as a consistent interface for controlling its visibility and the colour of the grid dots. (It uses dots rather than lines for its grid representation.) The grid layer is always locked an non-printing, while visibility and colour remain settable.
Having a separate grid layer may help in Inkscape if we use njh's suggestion for having canvas controls to edit the grid.
Skencil has a reasonable interface for named styles. Individual objects can override properties assigned by styles, and there is an "Update style" command to copy those changes back to the style.
There are some gaps in the interface: when creating a style, one can control whether the style controls line thickness, but I didn't see a way of changing that after creation. There seem to be some inconsistencies about whether an object can belong to more than one style or not.
Skencil style control certainly isn't as sophisticated as that offered by SVG/CSS, but we may borrow some things from it.
(Inkscape doesn't support named styles, unless you count inheriting styles from parents, such as layer membership.)
Ellipses/Arcs: node editing
Like Inkscape, Skencil uses one tool for circles, ellipses and arcs. It uses the opposite convention for whether to show radial spokes (pacman, pie slice) or whether to show just the arc (with chord filling if filled): if the node tool is dragged outside of the corresponding ellipse, then it's a chord/pure arc in Skencil, whereas inside means pie slice / pacman.
For unfilled shapes, I think Skencil's choice is better (partly because pure arcs are more common than pie slices when unfilled, so it's good to assign it the alternative that gives more control.
For filled shapes, the argument of more-common-deserves-outside goes in Inkscape's favour.
When editing the placement of the radial spokes, it's slightly more intuitive putting the mouse inside the ellipse; though this is a minor argument.
Can we use Inkscape plugins to access any sketch features? Its web page says "many parts of Skencil can be used as a library (and are used by Skencil that way)".
Notable things missing from Skencil yet present in Inkscape
- Transparence in gradients.
- Better support for patterns.
- Better SVG support, as one would expect. (SVG is a foreign format for Skencil.)
- Skencil stable version 0.6.x uses tk interface. (Development version 0.7.x uses gtk.)
(The above are things skencil users find lacking, I haven't tried going through Inkscape's release notes doing a point-by-point comparison.)