The basics: path editing

[BobInce]

OK, so with some people complaining that Xara is concentrating of fripperies instead of the core feature set, what changes actually need making to the core features?

I contend not a lot, but I've always felt the path tool was a bit wobblier than I'd like. I've just spent a few minutes playing with it to try to track down exactly what the problems are and here's my conclusions:

1. When changing a cusp join into a smooth join node, the bezier control points seem to go in fairly random directions; the resulting through-line isn't the tangent of the line of one side of the node, or the other, or even necessarily in between! There's not a conclusive optimum solution to the problem of where the line should point, but the current implementation doesn't seem ideal for any common case (unless it's doing something 'clever' I don't understand at all).

Suggest maybe taking the the original line directions, and picking the angle halfway between them, then moving the control points to the nearest point they are to that tangent line? Or choosing one control point to keep in place, moving the other to the nearest point on the tangent line implied by that control point? Perhaps a control modifier key to change the choice of constant-control-point, or some arbitrary choice like which control point is nearest to the edge of the line?

2. When you close a shape by dragging an endpoint of a straight line into the other end node which is at the end of a curve, the node at the closing point gets into a state where it is, according to the infobar, neither a cusp nor a smooth join. It behaves like a cusp join until an adjacent straight line is dragged, then it snaps to an unwanted smooth join. It can be fixed manually by setting the node to a cusp join before dragging, but this shouldn't really be necessary.

3. When drawing a curved path and placing a new point, the behaviour of the line at the previous point varies. If you have not moved the previous node's control point, the tangent at the previous node is changed when you place the new one, to curve around to the new point more easily. This is good behaviour for when you're quickly clicking around an outline and want nice smooth curves. However if you have moved the previous node's control point, it stays where it is, and the line diverges at that point towards the new one at an arbitrary angle.

This is reasonable behaviour if the previous node was a cusp join (I'm not sure if a straight curve to the new point would be more likely right or less). But if the previous node was a smooth join, it breaks: the previous node is still a smooth join according to the infobar, but the lines going into it are at different angles. Editing control points around it causes it to snap back to a smooth join, which is usually surprising and undesirable.

4. Sometimes bezier control points get 'stuck' in an absolute position, and don't move when the associated node point is moved. No idea what causes this as it seems to turn up rarely and randomly in path editing with no obvious trigger. I suspect this may be a deliberate behaviour, but can't work out when or why that might be.

5. Having to go to the line gallery to change line settings feels odd, as it is (as far as I'm aware) the only gallery that directly controls attributes of the selected object instead of being a store for shortcuts. Direct attribute controls are normally on the primary-interface toolbars. For example line width is already on the main toolbar.

Seems to me that at least the join and cap type dropdowns should be on the infobar, either for the path tool or the freehand tool where the stroke/brush settings are. (Speaking of which I still find it odd that stroke and brush are here and not in the path tool, since they're for paths in general not just freehand ones.)

6. I've only just spotted the 'smoothing' control on path tool, and after working out what it does that's quite cool! It would be even better if it could smooth straight lines, so you could select a straight-line path and approximate a curve to it.

7. Not sure if this is technically a path tool fault, but it seems to occur only when I'm doing a lot of path work. Something causes the state of the 'view selection bounds handles' option to toggle, without updating the state of the button for it on the select tool infobar, which then goes out-of-sync so it looks pushed in when the handles are disabled and vice-versa.

I think this may be new in Xtreme 4. Certainly it never happened to be in 2.

cheers,