Add ShowLabels component, which controls whether instances’ labels …

…are shown. (#7249)

* Implements #3465

### What
* Each archetype which has labels gets a `ShowLabels` non-repeated
component. (I figured having it set per-instance would be hardly ever
useful.)
* Visualizers pass this component to `process_labels()`.
* `process_labels()` uses it to override the existing “show labels if
less than 30” policy.
* Refactoring: `process_labels()` and friends now take a struct instead
of 8 separate parameters. This makes the callsites more legible and
maintainable, and might eventually be useful for further refinement of
the label rendering system (it's basically a "ComponentData" struct for
labels).

One element is currently missing: the automatic policy is not expressed
as a component fallback. That means that the viewer UI does not know
about it and won't display the real fallback value, but a bogus constant
`true`. Other than that, it should be fully ready to go, so feel free to
either merge or wait for that further work as you see fit.

### Checklist
* [X] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [X] I've included a screenshot or gif (if applicable)
* [ ] I have tested the web demo (if applicable):
* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/7249?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/7249?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [X] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [X] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!
* [X] If have noted any breaking changes to the log API in
`CHANGELOG.md` and the migration guide

- [PR Build Summary](https://build.rerun.io/pr/7249)
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

To run all checks from `main`, comment on the PR with `@rerun-bot
full-check`.

---------

Co-authored-by: Emil Ernerfeldt <[email protected]>

crates/store/re_types/definitions/rerun/archetypes/arrows2d.fbs

@@ -42,6 +42,9 @@ table Arrows2D (
   /// Otherwise, each instance will have its own label.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3200);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3250);
+
   /// An optional floating point value that specifies the 2D drawing order.
   ///
   /// Objects with higher values are drawn on top of those with lower values.

crates/store/re_types/definitions/rerun/archetypes/arrows3d.fbs

@@ -41,6 +41,9 @@ table Arrows3D (
   /// Otherwise, each instance will have its own label.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3200);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3250);
+
   /// Optional class Ids for the points.
   ///
   /// The [components.ClassId] provides colors and labels if not specified explicitly.

crates/store/re_types/definitions/rerun/archetypes/boxes2d.fbs

@@ -40,6 +40,9 @@ table Boxes2D (
   /// Otherwise, each instance will have its own label.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3000);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3050);
+
   /// An optional floating point value that specifies the 2D drawing order.
   ///
   /// Objects with higher values are drawn on top of those with lower values.

crates/store/re_types/definitions/rerun/archetypes/boxes3d.fbs

@@ -59,6 +59,9 @@ table Boxes3D (
   /// Otherwise, each instance will have its own label.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3200);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3250);
+
   /// Optional [components.ClassId]s for the boxes.
   ///
   /// The [components.ClassId] provides colors and labels if not specified explicitly.

crates/store/re_types/definitions/rerun/archetypes/ellipsoids3d.fbs

@@ -61,6 +61,9 @@ table Ellipsoids3D (
   /// Optional text labels for the ellipsoids.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3200);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3250);
+
   /// Optional class ID for the ellipsoids.
   ///
   /// The class ID provides colors and labels if not specified explicitly.

crates/store/re_types/definitions/rerun/archetypes/line_strips2d.fbs

@@ -34,6 +34,9 @@ table LineStrips2D (
   /// Otherwise, each instance will have its own label.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3000);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3050);
+
   /// An optional floating point value that specifies the 2D drawing order of each line strip.
   ///
   /// Objects with higher values are drawn on top of those with lower values.

crates/store/re_types/definitions/rerun/archetypes/line_strips3d.fbs

@@ -34,6 +34,9 @@ table LineStrips3D (
   /// Otherwise, each instance will have its own label.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3000);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3050);
+
   /// Optional [components.ClassId]s for the lines.
   ///
   /// The [components.ClassId] provides colors and labels if not specified explicitly.

crates/store/re_types/definitions/rerun/archetypes/points2d.fbs

@@ -38,6 +38,9 @@ table Points2D (
   /// Otherwise, each instance will have its own label.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3000);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3050);
+
   /// An optional floating point value that specifies the 2D drawing order.
   ///
   /// Objects with higher values are drawn on top of those with lower values.

crates/store/re_types/definitions/rerun/archetypes/points3d.fbs

@@ -37,6 +37,9 @@ table Points3D (
   /// Otherwise, each instance will have its own label.
   labels: [rerun.components.Text] ("attr.rerun.component_optional", nullable, order: 3000);
 
+  /// Optional choice of whether the text labels should be shown by default.
+  show_labels: rerun.components.ShowLabels ("attr.rerun.component_optional", nullable, order: 3100);
+
   /// Optional class Ids for the points.
   ///
   /// The [components.ClassId] provides colors and labels if not specified explicitly.

crates/store/re_types/definitions/rerun/components/show_labels.fbs

@@ -0,0 +1,20 @@
+
+namespace rerun.components;
+
+// ---
+
+/// Whether the entity's [components.Text] label is shown.
+///
+/// The main purpose of this component existing separately from the labels themselves
+/// is to be overridden when desired, to allow hiding and showing from the viewer and
+/// blueprints.
+struct ShowLabels (
+  "attr.arrow.transparent",
+  "attr.python.aliases": "bool",
+  "attr.python.array_aliases": "bool, npt.NDArray[np.bool_]",
+  "attr.rust.derive": "Copy, PartialEq, Eq",
+  "attr.rust.tuple_struct"
+) {
+  /// Whether the entity's [components.Text] label is shown.
+  show_labels: rerun.datatypes.Bool (order: 100);
+}