# Objective
- Improve reproducibility of examples
## Solution
- Use seeded rng when needed
- Use fixed z-ordering when needed
## Testing
```sh
steps=5;
echo "cpu_draw\nparallel_query\nanimated_fox\ntransparency_2d" > test
cargo run -p example-showcase -- run --stop-frame 250 --screenshot-frame 100 --fixed-frame-time 0.05 --example-list test --in-ci;
mv screenshots base;
for prefix in `seq 0 $steps`;
do
  echo step $prefix;
  cargo run -p example-showcase -- run --stop-frame 250 --screenshot-frame 100 --fixed-frame-time 0.05 --example-list test;
  mv screenshots $prefix-screenshots;
done;
mv base screenshots
for prefix in `seq 0 $steps`;
do
  echo check $prefix
  for file in screenshots/*/*;
  do
    echo $file;
    diff $file $prefix-$file;
  done;
done;
```
		
	
			
		
			
				
	
	
		
			37 lines
		
	
	
		
			1012 B
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			37 lines
		
	
	
		
			1012 B
		
	
	
	
		
			Rust
		
	
	
	
	
	
//! Demonstrates how to use transparency in 2D.
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//! Shows 3 bevy logos on top of each other, each with a different amount of transparency.
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use bevy::prelude::*;
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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, setup)
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        .run();
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}
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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    commands.spawn(Camera2d);
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    let sprite_handle = asset_server.load("branding/icon.png");
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    commands.spawn(Sprite::from_image(sprite_handle.clone()));
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    commands.spawn((
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        Sprite {
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            image: sprite_handle.clone(),
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            // Alpha channel of the color controls transparency.
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            color: Color::srgba(0.0, 0.0, 1.0, 0.7),
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            ..default()
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        },
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        Transform::from_xyz(100.0, 0.0, 0.1),
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    ));
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    commands.spawn((
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        Sprite {
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            image: sprite_handle,
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            color: Color::srgba(0.0, 1.0, 0.0, 0.3),
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            ..default()
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        },
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        Transform::from_xyz(200.0, 0.0, 0.2),
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    ));
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}
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