Hi Diederik,
Thanks for your message on thursday and apologies for not replying sooner; I've just been away on holiday.
Having thought about it I agree that the corel way does have its limitations, but at the same time I think it does encompass 99% of common translations by simply snapping at the handle, and I think it may be less than obvious what is happening otherwise as you say. Rather than 'preferring nodes' close to the mouse pointer though, I wonder about having the handles snap in the corel way but then introduce a new set of 'geometric transform' buttons in the upcoming 'Geometric constructions toolbar'.
These could work in a CAD like way. For example, once the 'Geomtric stretch' tool was selected inkscape would prompt for two consecutive inputs. First the user draws the line about which the stretch is to occur (this need not be within the shape in general), and second the point the shape is to be stretched from (which would use 'normal' node snapping). This would allow the transform to occur from any point, but also allow the flexibility to define different lines/points/grids about which the transform is to occur, and may work better with unusual (e.g. isometric) grids for stretching.
http://mathworld.wolfram.com/Stretch.html
The first input draws the invariant line, and the second provides the scale factor (which could of course be typed as a number alternatively) if it were a seperate tool.
Similarly the geometric rotation tool would first prompt for the 'centre of rotation' and then the point to 'pick up' from using standard node snapping (or a typed angle).
Incidently, what do you think about the snapping indicators they (corel) use?
Best Wishes, Alex
On Thu, 6 Nov 2008, Diederik van Lierop wrote:
Hello Alex,
Just downloaded a trial version of Coreldraw X4 and tried the snapping. Finally things are dawning on me.
When using the handles to transform (scaling/stretching/skewing/rotating), only the handles themselves snap. This is pretty limited because in many cases the handle is at a position that has little to do with the position of the nodes. I think the nodes should snap instead of the handles, as Inkscape does. A downside of this is that it's not always obvious which node is snapping, but this should be improved by preferring nodes closes to the mouse pointer over other nodes.
Consequently, nodes (and midpoints, intersections, centers, etc.) only snap when translating. Why's that? The only reasons I can think of is that they wanted to keep things simple.
Finally, the tangent and perpendicular snapping are only available when drawing lines, not when transforming. So they basically only have point to point/path snapping (just as Inkscape), and don't offer real line-to-line snapping either. Overall they provide a clean user experience, but it looks a bit restrictive in what can be done and the level of configurability is low. Let's try to do better!
Regards,
Diederik