mesh2d_alpha_mode/
mesh2d_alpha_mode.rs

1//! This example is used to test how transforms interact with alpha modes for [`Mesh2d`] entities with a [`MeshMaterial2d`].
2//! This makes sure the depth buffer is correctly being used for opaque and transparent 2d meshes
3
4use bevy::{
5    color::palettes::css::{BLUE, GREEN, WHITE},
6    prelude::*,
7    sprite_render::AlphaMode2d,
8};
9
10fn main() {
11    App::new()
12        .add_plugins(DefaultPlugins)
13        .add_systems(Startup, setup)
14        .run();
15}
16
17fn setup(
18    mut commands: Commands,
19    asset_server: Res<AssetServer>,
20    mut meshes: ResMut<Assets<Mesh>>,
21    mut materials: ResMut<Assets<ColorMaterial>>,
22) {
23    commands.spawn(Camera2d);
24
25    let texture_handle = asset_server.load("branding/icon.png");
26    let mesh_handle = meshes.add(Rectangle::from_size(Vec2::splat(256.0)));
27
28    // opaque
29    // Each sprite should be square with the transparent parts being completely black
30    // The blue sprite should be on top with the white and green one behind it
31    commands.spawn((
32        Mesh2d(mesh_handle.clone()),
33        MeshMaterial2d(materials.add(ColorMaterial {
34            color: WHITE.into(),
35            alpha_mode: AlphaMode2d::Opaque,
36            texture: Some(texture_handle.clone()),
37            ..default()
38        })),
39        Transform::from_xyz(-400.0, 0.0, 0.0),
40    ));
41    commands.spawn((
42        Mesh2d(mesh_handle.clone()),
43        MeshMaterial2d(materials.add(ColorMaterial {
44            color: BLUE.into(),
45            alpha_mode: AlphaMode2d::Opaque,
46            texture: Some(texture_handle.clone()),
47            ..default()
48        })),
49        Transform::from_xyz(-300.0, 0.0, 1.0),
50    ));
51    commands.spawn((
52        Mesh2d(mesh_handle.clone()),
53        MeshMaterial2d(materials.add(ColorMaterial {
54            color: GREEN.into(),
55            alpha_mode: AlphaMode2d::Opaque,
56            texture: Some(texture_handle.clone()),
57            ..default()
58        })),
59        Transform::from_xyz(-200.0, 0.0, -1.0),
60    ));
61
62    // Test the interaction between opaque/mask and transparent meshes
63    // The white sprite should be:
64    // - only the icon is opaque but background is transparent
65    // - on top of the green sprite
66    // - behind the blue sprite
67    commands.spawn((
68        Mesh2d(mesh_handle.clone()),
69        MeshMaterial2d(materials.add(ColorMaterial {
70            color: WHITE.into(),
71            alpha_mode: AlphaMode2d::Mask(0.5),
72            texture: Some(texture_handle.clone()),
73            ..default()
74        })),
75        Transform::from_xyz(200.0, 0.0, 0.0),
76    ));
77    commands.spawn((
78        Mesh2d(mesh_handle.clone()),
79        MeshMaterial2d(materials.add(ColorMaterial {
80            color: BLUE.with_alpha(0.7).into(),
81            alpha_mode: AlphaMode2d::Blend,
82            texture: Some(texture_handle.clone()),
83            ..default()
84        })),
85        Transform::from_xyz(300.0, 0.0, 1.0),
86    ));
87    commands.spawn((
88        Mesh2d(mesh_handle.clone()),
89        MeshMaterial2d(materials.add(ColorMaterial {
90            color: GREEN.with_alpha(0.7).into(),
91            alpha_mode: AlphaMode2d::Blend,
92            texture: Some(texture_handle),
93            ..default()
94        })),
95        Transform::from_xyz(400.0, 0.0, -1.0),
96    ));
97}
mesh2d_alpha_mode/mesh2d_alpha_mode.rs

mesh2d_alpha_mode/
mesh2d_alpha_mode.rs
