Retained Gizmos (#15473)

# Objective
Add a way to use the gizmo API in a retained manner, for increased
performance.

## Solution
- Move gizmo API from `Gizmos` to `GizmoBuffer`, ~ab~using `Deref` to
keep usage the same as before.
- Merge non-strip and strip variant of `LineGizmo` into one, storing the
data in a `GizmoBuffer` to have the same API for retained `LineGizmo`s.

### Review guide
- The meat of the changes are in `lib.rs`, `retained.rs`, `gizmos.rs`,
`pipeline_3d.rs` and `pipeline_2d.rs`
- The other files contain almost exclusively the churn from moving the
gizmo API from `Gizmos` to `GizmoBuffer`

## Testing
### Performance

Performance compared to the immediate mode API is from 65 to 80 times
better for static lines.

```
7900 XTX, 3700X
1707.9k lines/ms: gizmos_retained (21.3ms)
3488.5k lines/ms: gizmos_retained_continuous_polyline (31.3ms)
   0.5k lines/ms: gizmos_retained_separate (97.7ms)

3054.9k lines/ms: bevy_polyline_retained_nan (16.8ms)
3596.3k lines/ms: bevy_polyline_retained_continuous_polyline (14.2ms)
   0.6k lines/ms: bevy_polyline_retained_separate (78.9ms)

  26.9k lines/ms: gizmos_immediate (14.9ms)
  43.8k lines/ms: gizmos_immediate_continuous_polyline (18.3ms)
```
Looks like performance is good enough, being close to par with
`bevy_polyline`.

Benchmarks can be found here: 
This branch:
https://github.com/tim-blackbird/line_racing/tree/retained-gizmos
Bevy 0.14: https://github.com/DGriffin91/line_racing

## Showcase
```rust 
fn setup(
    mut commands: Commands,
    mut gizmo_assets: ResMut<Assets<GizmoAsset>>
) {
    let mut gizmo = GizmoAsset::default();

    // A sphere made out of one million lines!
    gizmo
        .sphere(default(), 1., CRIMSON)
        .resolution(1_000_000 / 3);

    commands.spawn(Gizmo {
        handle: gizmo_assets.add(gizmo),
        ..default()
    });
}
```

## Follow-up work
- Port over to the retained rendering world proper
- Calculate visibility and cull `Gizmo`s

Author: tim-blackbird

crates/bevy_dev_tools/src/ui_debug_overlay/inset.rs

@@ -184,9 +184,9 @@ impl<'w, 's> InsetGizmo<'w, 's> {
                 Vec2::new(right, bottom),
                 Vec2::new(right, top),
                 Vec2::new(left, top),
-            ];
-            self.draw
-                .linestrip_2d(strip.map(|v| self.relative(v)), color);
+            ]
+            .map(|v| self.relative(v));
+            self.draw.linestrip_2d(strip, color);
         }
     }
 }

crates/bevy_dev_tools/src/ui_debug_overlay/mod.rs

@@ -204,7 +204,7 @@ fn outline_roots(
     let line_width = outline
         .gizmo_config
         .get_config_dyn(&UiGizmosDebug.type_id())
-        .map_or(2., |(config, _)| config.line_width)
+        .map_or(2., |(config, _)| config.line.width)
         / window_scale;
     let mut draw = InsetGizmo::new(draw, cam.debug_camera, line_width);
     for (entity, trans, node, view_visibility, maybe_target_camera) in &roots {

crates/bevy_gizmos/src/arcs.rs

@@ -1,19 +1,16 @@
-//! Additional [`Gizmos`] Functions -- Arcs
+//! Additional [`GizmoBuffer`] Functions -- Arcs
 //!
-//! Includes the implementation of [`Gizmos::arc_2d`],
+//! Includes the implementation of [`GizmoBuffer::arc_2d`],
 //! and assorted support items.
 
-use crate::{
-    circles::DEFAULT_CIRCLE_RESOLUTION,
-    prelude::{GizmoConfigGroup, Gizmos},
-};
+use crate::{circles::DEFAULT_CIRCLE_RESOLUTION, gizmos::GizmoBuffer, prelude::GizmoConfigGroup};
 use bevy_color::Color;
 use bevy_math::{Isometry2d, Isometry3d, Quat, Rot2, Vec2, Vec3};
 use core::f32::consts::{FRAC_PI_2, TAU};
 
 // === 2D ===
 
-impl<'w, 's, Config, Clear> Gizmos<'w, 's, Config, Clear>
+impl<Config, Clear> GizmoBuffer<Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
@@ -54,7 +51,7 @@ where
         arc_angle: f32,
         radius: f32,
         color: impl Into<Color>,
-    ) -> Arc2dBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> Arc2dBuilder<'_, Config, Clear> {
         Arc2dBuilder {
             gizmos: self,
             isometry: isometry.into(),
@@ -66,21 +63,21 @@ where
     }
 }
 
-/// A builder returned by [`Gizmos::arc_2d`].
-pub struct Arc2dBuilder<'a, 'w, 's, Config, Clear>
+/// A builder returned by [`GizmoBuffer::arc_2d`].
+pub struct Arc2dBuilder<'a, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
 {
-    gizmos: &'a mut Gizmos<'w, 's, Config, Clear>,
+    gizmos: &'a mut GizmoBuffer<Config, Clear>,
     isometry: Isometry2d,
     arc_angle: f32,
     radius: f32,
     color: Color,
     resolution: Option<u32>,
 }
 
-impl<Config, Clear> Arc2dBuilder<'_, '_, '_, Config, Clear>
+impl<Config, Clear> Arc2dBuilder<'_, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
@@ -92,7 +89,7 @@ where
     }
 }
 
-impl<Config, Clear> Drop for Arc2dBuilder<'_, '_, '_, Config, Clear>
+impl<Config, Clear> Drop for Arc2dBuilder<'_, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
@@ -122,7 +119,7 @@ fn arc_2d_inner(arc_angle: f32, radius: f32, resolution: u32) -> impl Iterator<I
 
 // === 3D ===
 
-impl<'w, 's, Config, Clear> Gizmos<'w, 's, Config, Clear>
+impl<Config, Clear> GizmoBuffer<Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
@@ -178,7 +175,7 @@ where
         radius: f32,
         isometry: impl Into<Isometry3d>,
         color: impl Into<Color>,
-    ) -> Arc3dBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> Arc3dBuilder<'_, Config, Clear> {
         Arc3dBuilder {
             gizmos: self,
             start_vertex: Vec3::X,
@@ -233,7 +230,7 @@ where
         from: Vec3,
         to: Vec3,
         color: impl Into<Color>,
-    ) -> Arc3dBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> Arc3dBuilder<'_, Config, Clear> {
         self.arc_from_to(center, from, to, color, |x| x)
     }
 
@@ -279,7 +276,7 @@ where
         from: Vec3,
         to: Vec3,
         color: impl Into<Color>,
-    ) -> Arc3dBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> Arc3dBuilder<'_, Config, Clear> {
         self.arc_from_to(center, from, to, color, |angle| {
             if angle > 0.0 {
                 TAU - angle
@@ -299,7 +296,7 @@ where
         to: Vec3,
         color: impl Into<Color>,
         angle_fn: impl Fn(f32) -> f32,
-    ) -> Arc3dBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> Arc3dBuilder<'_, Config, Clear> {
         // `from` and `to` can be the same here since in either case nothing gets rendered and the
         // orientation ambiguity of `up` doesn't matter
         let from_axis = (from - center).normalize_or_zero();
@@ -366,7 +363,7 @@ where
         from: Vec2,
         to: Vec2,
         color: impl Into<Color>,
-    ) -> Arc2dBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> Arc2dBuilder<'_, Config, Clear> {
         self.arc_2d_from_to(center, from, to, color, core::convert::identity)
     }
 
@@ -412,7 +409,7 @@ where
         from: Vec2,
         to: Vec2,
         color: impl Into<Color>,
-    ) -> Arc2dBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> Arc2dBuilder<'_, Config, Clear> {
         self.arc_2d_from_to(center, from, to, color, |angle| angle - TAU)
     }
 
@@ -424,7 +421,7 @@ where
         to: Vec2,
         color: impl Into<Color>,
         angle_fn: impl Fn(f32) -> f32,
-    ) -> Arc2dBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> Arc2dBuilder<'_, Config, Clear> {
         // `from` and `to` can be the same here since in either case nothing gets rendered and the
         // orientation ambiguity of `up` doesn't matter
         let from_axis = (from - center).normalize_or_zero();
@@ -446,13 +443,13 @@ where
     }
 }
 
-/// A builder returned by [`Gizmos::arc_2d`].
-pub struct Arc3dBuilder<'a, 'w, 's, Config, Clear>
+/// A builder returned by [`GizmoBuffer::arc_2d`].
+pub struct Arc3dBuilder<'a, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
 {
-    gizmos: &'a mut Gizmos<'w, 's, Config, Clear>,
+    gizmos: &'a mut GizmoBuffer<Config, Clear>,
     // this is the vertex the arc starts on in the XZ plane. For the normal arc_3d method this is
     // always starting at Vec3::X. For the short/long arc methods we actually need a way to start
     // at the from position and this is where this internal field comes into play. Some implicit
@@ -470,7 +467,7 @@ where
     resolution: Option<u32>,
 }
 
-impl<Config, Clear> Arc3dBuilder<'_, '_, '_, Config, Clear>
+impl<Config, Clear> Arc3dBuilder<'_, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
@@ -482,7 +479,7 @@ where
     }
 }
 
-impl<Config, Clear> Drop for Arc3dBuilder<'_, '_, '_, Config, Clear>
+impl<Config, Clear> Drop for Arc3dBuilder<'_, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,

crates/bevy_gizmos/src/arrows.rs

@@ -1,31 +1,31 @@
-//! Additional [`Gizmos`] Functions -- Arrows
+//! Additional [`GizmoBuffer`] Functions -- Arrows
 //!
-//! Includes the implementation of [`Gizmos::arrow`] and [`Gizmos::arrow_2d`],
+//! Includes the implementation of [`GizmoBuffer::arrow`] and [`GizmoBuffer::arrow_2d`],
 //! and assorted support items.
 
-use crate::prelude::{GizmoConfigGroup, Gizmos};
+use crate::{gizmos::GizmoBuffer, prelude::GizmoConfigGroup};
 use bevy_color::{
     palettes::basic::{BLUE, GREEN, RED},
     Color,
 };
 use bevy_math::{Quat, Vec2, Vec3, Vec3Swizzles};
 use bevy_transform::TransformPoint;
 
-/// A builder returned by [`Gizmos::arrow`] and [`Gizmos::arrow_2d`]
-pub struct ArrowBuilder<'a, 'w, 's, Config, Clear>
+/// A builder returned by [`GizmoBuffer::arrow`] and [`GizmoBuffer::arrow_2d`]
+pub struct ArrowBuilder<'a, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
 {
-    gizmos: &'a mut Gizmos<'w, 's, Config, Clear>,
+    gizmos: &'a mut GizmoBuffer<Config, Clear>,
     start: Vec3,
     end: Vec3,
     color: Color,
     double_ended: bool,
     tip_length: f32,
 }
 
-impl<Config, Clear> ArrowBuilder<'_, '_, '_, Config, Clear>
+impl<Config, Clear> ArrowBuilder<'_, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
@@ -58,12 +58,12 @@ where
     }
 }
 
-impl<Config, Clear> Drop for ArrowBuilder<'_, '_, '_, Config, Clear>
+impl<Config, Clear> Drop for ArrowBuilder<'_, Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
 {
-    /// Draws the arrow, by drawing lines with the stored [`Gizmos`]
+    /// Draws the arrow, by drawing lines with the stored [`GizmoBuffer`]
     fn drop(&mut self) {
         if !self.gizmos.enabled {
             return;
@@ -101,7 +101,7 @@ where
     }
 }
 
-impl<'w, 's, Config, Clear> Gizmos<'w, 's, Config, Clear>
+impl<Config, Clear> GizmoBuffer<Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,
@@ -125,7 +125,7 @@ where
         start: Vec3,
         end: Vec3,
         color: impl Into<Color>,
-    ) -> ArrowBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> ArrowBuilder<'_, Config, Clear> {
         let length = (end - start).length();
         ArrowBuilder {
             gizmos: self,
@@ -156,12 +156,12 @@ where
         start: Vec2,
         end: Vec2,
         color: impl Into<Color>,
-    ) -> ArrowBuilder<'_, 'w, 's, Config, Clear> {
+    ) -> ArrowBuilder<'_, Config, Clear> {
         self.arrow(start.extend(0.), end.extend(0.), color)
     }
 }
 
-impl<'w, 's, Config, Clear> Gizmos<'w, 's, Config, Clear>
+impl<Config, Clear> GizmoBuffer<Config, Clear>
 where
     Config: GizmoConfigGroup,
     Clear: 'static + Send + Sync,