Something was bothering me a bit with the discussion around sqrt's being
slow. Looks like `Math.hypot` has a performance cost associated with it.
Looking at the Chromium source code:
https://chromium.googlesource.com/v8/v8/+/4.3.21/src/math.js?autodive=0%2F%2F#19
and
https://source.chromium.org/chromium/chromium/src/+/main:v8/src/builtins/math.tq;l=36?q=math&sq=&ss=chromium%2Fchromium%2Fsrc:v8%2Fsrc%2F
it looks like maybe we'd be avoiding the multiple arguments that can be
passed into Math.hypot which is maybe the source of the perf hit.
Also, interestingly in `math.tq` you can see it doing this funky sqrt
calculation: `Float64Sqrt((a / max) * (a / max) + (b / max) * (b / max))
* max` - I think that possibly is trying to avoid some overflow in some
cases with bigger numbers, but also possibly with a perf hit.
[edit]: OK, actually on Firefox, doing sqrt seems slower - but digging
more into this, it looks like doing `** 0.5` instead of `sqrt` is much
faster.
More related articles:
- https://stackoverflow.com/questions/71898044/why-is-math-hypot-so-slow
-
https://stackoverflow.com/questions/3764978/why-hypot-function-is-so-slow
-
https://www.reddit.com/r/javascript/comments/wk3e57/askjs_why_mathsqrt_is_so_slow_in_firefox/
[edit again!] looks like this is being fixed in the latest Chrome!
https://blog.seokho.dev/development/2024/03/18/V8-optimize-MathHypot.html
```
┌─────────┬───────┬─────────┬─────────┬─────────┬────────┐
│ (index) │ Cold │ Slowest │ Fastest │ Average │ Total │
├─────────┼───────┼─────────┼─────────┼─────────┼────────┤
│ old │ 13.39 │ 10.07 │ 9.69 │ 9.98 │ 998.57 │
│ sqrt │ 8.19 │ 6.66 │ 6.61 │ 6.67 │ 667.6 │
│ pow 0.5 │ 1.89 │ 0.28 │ 0.28 │ 0.3 │ 29.79 │
│ new │ 1.64 │ 0.28 │ 0.28 │ 0.29 │ 28.95 │
└─────────┴───────┴─────────┴─────────┴─────────┴────────┘
```
### Change Type
<!-- ❗ Please select a 'Scope' label ❗️ -->
- [x] `sdk` — Changes the tldraw SDK
- [ ] `dotcom` — Changes the tldraw.com web app
- [ ] `docs` — Changes to the documentation, examples, or templates.
- [ ] `vs code` — Changes to the vscode plugin
- [ ] `internal` — Does not affect user-facing stuff
<!-- ❗ Please select a 'Type' label ❗️ -->
- [ ] `bugfix` — Bug fix
- [ ] `feature` — New feature
- [x] `improvement` — Improving existing features
- [ ] `chore` — Updating dependencies, other boring stuff
- [ ] `galaxy brain` — Architectural changes
- [ ] `tests` — Changes to any test code
- [ ] `tools` — Changes to infrastructure, CI, internal scripts,
debugging tools, etc.
- [ ] `dunno` — I don't know
This PR makes a small improvement to the way we measure distances.
(Often we measure distances multiple times per frame per shape on the
screen). In many cases, we compare a minimum distance. This makes those
checks faster by avoiding a square root.
### Change Type
- [x] `sdk` — Changes the tldraw SDK
- [x] `improvement` — Improving existing features
### Release Notes
- Improve performance of minimum distance checks.
This PR improves a bunch of places where we do "minimum distance
checks". Previously, we were using `Vec.Dist`, which uses `Math.hypot`
to find the actual distance, but we can just as well use the squared
distance. So this PR makes a small improvement to `Vec.Dist2` and then
switches to that method when checking minimum distances.
### Change Type
- [x] `sdk` — Changes the tldraw SDK
- [x] `improvement` — Improving existing features
### Test Plan
- [x] Unit Tests
### Release Notes
- Performance: small improvements to hit testing.
Should fix `At instance.duplicateProps.offset.x: Expected a number, got
NaN` validation errors.
Wasn't able to reproduce. We only assign the offset here, so
`Vec.Averge` is the most likely offender here and for that to happen I
guess `movingShapes` might not contain any shapes.
### Change Type
- [x] `patch` — Bug fix
- [ ] `minor` — New feature
- [ ] `major` — Breaking change
- [ ] `dependencies` — Changes to package dependencies[^1]
- [ ] `documentation` — Changes to the documentation only[^2]
- [ ] `tests` — Changes to any test code only[^2]
- [ ] `internal` — Any other changes that don't affect the published
package[^2]
- [ ] I don't know
[^1]: publishes a `patch` release, for devDependencies use `internal`
[^2]: will not publish a new version
### Test Plan
1. Add a step-by-step description of how to test your PR here.
2.
- [ ] Unit Tests
- [ ] End to end tests
### Release Notes
- Add a brief release note for your PR here.
This would happen when trying to translate a zero-width bound arrow.
### Change Type
- [x] `patch` — Bug fix
### Release Notes
- Fixes zero-width arrow NaN computation when moving the label.
This adds the ability to drag the label on an arrow to a different
location within the line segment/arc.
https://github.com/tldraw/tldraw/assets/469604/dbd2ee35-bebc-48d6-b8ee-fcf12ce91fa5
- A lot of the complexity lay in ensuring a fixed distance from the ends
of the arrowheads.
- I added a new type of handle `text-adjust` that makes the text box the
very handle itself.
- I added a `ARROW_HANDLES` enum - we should use more enums!
- The bulk of the changes are in ArrowShapeUtil — check that out in
particular obviously :)
Along the way, I tried to improve a couple spots as I touched them:
- added some more documentation to Vec.ts because some of the functions
in there were obscure/new to me. (at least the naming, hah)
- added `getPointOnCircle` which was being done in a couple places
independently and refactored those places.
### Questions
- the `getPointOnCircle` API changed. Is this considered breaking and/or
should I leave the signature the same? Wasn't sure if it was a big deal
or not.
- I made `labelPosition` in the schema always but I guess it could have
been optional? Lemme know if there's a preference.
- Any feedback on tests? Happy to expand those if necessary.
### Change Type
- [ ] `patch` — Bug fix
- [x] `minor` — New feature
- [ ] `major` — Breaking change
- [ ] `dependencies` — Changes to package dependencies[^1]
- [ ] `documentation` — Changes to the documentation only[^2]
- [ ] `tests` — Changes to any test code only[^2]
- [ ] `internal` — Any other changes that don't affect the published
package[^2]
- [ ] I don't know
[^1]: publishes a `patch` release, for devDependencies use `internal`
[^2]: will not publish a new version
### Test Plan
1. For arrow in [straightArrow, curvedArrow] test the following:
a. Label in the middle
b. Label at both ends of the arrow
c. Test arrows in different directions
d. Rotating the endpoints and seeing that the label stays at the end of
the arrow at a fixed width.
e. Test different stroke widths.
f. Test with different arrowheads.
2. Also, test arcs that are more circle like than arc-like.
- [x] Unit Tests
- [ ] End to end tests
### Release Notes
- Adds ability to change label position on arrows.
---------
Co-authored-by: Steve Ruiz <steveruizok@gmail.com>
Co-authored-by: alex <alex@dytry.ch>
This PR adds the docs app back into the tldraw monorepo.
## Deploying
We'll want to update our deploy script to update the SOURCE_SHA to the
newest release sha... and then deploy the docs pulling api.json files
from that release. We _could_ update the docs on every push to main, but
we don't have to unless something has changed. Right now there's no
automated deployments from this repo.
## Side effects
To make this one work, I needed to update the lock file. This might be
ok (new year new lock file), and everything builds as expected, though
we may want to spend some time with our scripts to be sure that things
are all good.
I also updated our prettier installation, which decided to add trailing
commas to every generic type. Which is, I suppose, [correct
behavior](https://github.com/prettier/prettier-vscode/issues/955)? But
that caused diffs in every file, which is unfortunate.
### Change Type
- [x] `internal` — Any other changes that don't affect the published
package[^2]
David Sheldrick