This PR makes several improvements to the behavior of arrows as they
relate to precision and container relationships.
- an arrow's terminals are always "true" and are never snapped to { x:
.5, y: .5 } as they were previously when not precise
- instead, a new `isPrecise` boolean is added to the arrow terminal
- when an arrow terminal renders "imprecisely" it will be placed to the
center of the bound shape
- when an arrow terminal renders "precisely" it will be placed at the
normalized location within the bound shape
The logic now is...
- if the user has indicated precision by "pausing" while drawing the
arrow, it will be precise
- otherwise...
- if both of an arrow's terminals are bound to the same shape, both will
be precise
- if a terminal is bound to a shape that contains the shape that its
opposite terminal is bound to, it will be precise
- if a terminal is bound to a shape that contains the shape that its
opposite terminal is bound to, it will be precise
- or else it will be imprecise
If the spatial relationships change, the precision may change as well.
Fixes https://github.com/tldraw/tldraw/issues/2204
Note: a previous version of this PR was based around ancestry but that's
not actually important.
### Change Type
- [x] `minor` — New feature
### Test Plan
1. Draw an arrow between a frame and its descendant
2. Draw an arrow inside of a shape to another shape contained within the
bounds of the big shape
3. Vis versa
4. Vis versa
- [x] Unit Tests
### Release Notes
- Improves the logic about when to draw "precise" arrows between the
center of bound shapes.
7d699a749f