 b6a2fc5d80
			
		
	
	
		b6a2fc5d80
		
			
		
	
	
	
	
		
			
			# Objective
- Some examples crash in CI because of needing too many resources for
the windows runner
- Some examples have random results making it hard to compare
screenshots
## Solution
- `bloom_3d`: reduce the number of spheres
- `pbr`:  use simpler spheres and reuse the mesh
- `tonemapping`: use simpler spheres and reuse the mesh
- `shadow_biases`: reduce the number of spheres
- `spotlight`: use a seeded rng, move more cubes in view while reducing
the total number of cubes, and reuse meshes and materials
- `external_source_external_thread`, `iter_combinations`,
`parallel_query`: use a seeded rng
Examples of errors encountered:
```
Caused by:
    In Device::create_bind_group
      note: label = `bloom_upsampling_bind_group`
    Not enough memory left
```
```
Caused by:
    In Queue::write_buffer
    Parent device is lost
```
```
ERROR wgpu_core::device::life: Mapping failed Device(Lost)
```
		
	
			
		
			
				
	
	
		
			77 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
| //! Illustrates parallel queries with `ParallelIterator`.
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| 
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| use bevy::ecs::query::BatchingStrategy;
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| use bevy::prelude::*;
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| use rand::{rngs::StdRng, Rng, SeedableRng};
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| 
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| #[derive(Component, Deref)]
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| struct Velocity(Vec2);
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| 
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| fn spawn_system(mut commands: Commands, asset_server: Res<AssetServer>) {
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|     commands.spawn(Camera2dBundle::default());
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|     let texture = asset_server.load("branding/icon.png");
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|     let mut rng = StdRng::seed_from_u64(19878367467713);
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|     for _ in 0..128 {
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|         commands.spawn((
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|             SpriteBundle {
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|                 texture: texture.clone(),
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|                 transform: Transform::from_scale(Vec3::splat(0.1)),
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|                 ..default()
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|             },
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|             Velocity(20.0 * Vec2::new(rng.gen::<f32>() - 0.5, rng.gen::<f32>() - 0.5)),
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|         ));
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|     }
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| }
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| 
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| // Move sprites according to their velocity
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| fn move_system(mut sprites: Query<(&mut Transform, &Velocity)>) {
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|     // Compute the new location of each sprite in parallel on the
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|     // ComputeTaskPool
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|     //
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|     // This example is only for demonstrative purposes. Using a
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|     // ParallelIterator for an inexpensive operation like addition on only 128
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|     // elements will not typically be faster than just using a normal Iterator.
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|     // See the ParallelIterator documentation for more information on when
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|     // to use or not use ParallelIterator over a normal Iterator.
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|     sprites
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|         .par_iter_mut()
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|         .for_each(|(mut transform, velocity)| {
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|             transform.translation += velocity.extend(0.0);
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|         });
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| }
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| 
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| // Bounce sprites outside the window
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| fn bounce_system(windows: Query<&Window>, mut sprites: Query<(&Transform, &mut Velocity)>) {
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|     let window = windows.single();
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|     let width = window.width();
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|     let height = window.height();
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|     let left = width / -2.0;
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|     let right = width / 2.0;
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|     let bottom = height / -2.0;
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|     let top = height / 2.0;
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|     // The default batch size can also be overridden.
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|     // In this case a batch size of 32 is chosen to limit the overhead of
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|     // ParallelIterator, since negating a vector is very inexpensive.
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|     sprites
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|         .par_iter_mut()
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|         .batching_strategy(BatchingStrategy::fixed(32))
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|         .for_each(|(transform, mut v)| {
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|             if !(left < transform.translation.x
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|                 && transform.translation.x < right
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|                 && bottom < transform.translation.y
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|                 && transform.translation.y < top)
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|             {
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|                 // For simplicity, just reverse the velocity; don't use realistic bounces
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|                 v.0 = -v.0;
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|             }
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|         });
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| }
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| 
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| fn main() {
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|     App::new()
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|         .add_plugins(DefaultPlugins)
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|         .add_systems(Startup, spawn_system)
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|         .add_systems(Update, (move_system, bounce_system))
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|         .run();
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| }
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