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Bevy Minesweeper: Tiles and Components

#rust #gamedev #tutorial #bevy

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Assets

Let's complete our board, for this we will need assets:

  • A bomb png texture
  • A font

(You can use the assets from the tutorial repository)

Place your assets in an assets folder at the root of your project

├── Cargo.lock ├── Cargo.toml ├── assets │ ├── fonts │ │ └── my_font.ttf │ └── sprites │ ├── bomb.png ├── board_plugin │ ├── Cargo.toml │ └── src │ ├── components │ ├── lib.rs │ └── resources ├── src │ └── main.rs
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Let's load these assets in our create_board startup system.
For this we need to add an argument to the system:

 pub fn create_board( mut commands: Commands, board_options: Option<Res<BoardOptions>>, window: Res<WindowDescriptor>, asset_server: Res<AssetServer>, // The AssetServer resource ) {
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The AssetServer resource allows loading files from the assets folder.

We can now load our assets right at the beginning of the function and retrieve handles:

// lib.rs // .. let font = asset_server.load("fonts/pixeled.ttf"); let bomb_image = asset_server.load("sprites/bomb.png"); // ..
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Component declaration

Our tile map knows which tile is a bomb, a bomb neighbor or empty, but the ECS doesn't.
Let's declare components we will attach to our tile entities in our plugin under board_plugin/components with our Coordinates component:

  • board_plugin/src/components/bomb.rs
  • board_plugin/src/components/bomb_neighbor.rs
  • board_plugin/src/components/uncover.rs 
// board_plugin/src/components/mod.rs pub use bomb::Bomb; pub use bomb_neighbor::BombNeighbor; pub use uncover::Uncover; mod bomb; mod bomb_neighbor; mod uncover;
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Bomb

This component will identify a tile as a bomb

// bomb.rs use bevy::prelude::Component; /// Bomb component #[cfg_attr(feature = "debug", derive(bevy_inspector_egui::Inspectable))] #[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Component)] pub struct Bomb;
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Bomb neighbor

This component will identify a tile as bomb neighbor

use bevy::prelude::Component; /// Bomb neighbor component #[cfg_attr(feature = "debug", derive(bevy_inspector_egui::Inspectable))] #[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Component)] pub struct BombNeighbor { /// Number of neighbor bombs pub count: u8, }
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Uncover

This component will identify tiles to uncover, we will use it in part 6

use bevy::prelude::Component; /// Uncover component, indicates a covered tile that should be uncovered #[cfg_attr(feature = "debug", derive(bevy_inspector_egui::Inspectable))] #[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Component)] pub struct Uncover;
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Let's register the components for the debug inspector in our plugin:

// lib.rs #[cfg(feature = "debug")] use bevy_inspector_egui::RegisterInspectable; use components::*; impl Plugin for BoardPlugin { fn build(&self, app: &mut App) { // .. #[cfg(feature = "debug")] { // registering custom component to be able to edit it in inspector app.register_inspectable::<Coordinates>(); app.register_inspectable::<BombNeighbor>(); app.register_inspectable::<Bomb>(); app.register_inspectable::<Uncover>(); } } }
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Component use

Let's create a function for BoardPlugin creating a Text2DBundle for our bomb counters:

/// Generates the bomb counter text 2D Bundle for a given value fn bomb_count_text_bundle(count: u8, font: Handle<Font>, size: f32) -> Text2dBundle { // We retrieve the text and the correct color let (text, color) = ( count.to_string(), match count { 1 => Color::WHITE, 2 => Color::GREEN, 3 => Color::YELLOW, 4 => Color::ORANGE, _ => Color::PURPLE, }, ); // We generate a text bundle Text2dBundle { text: Text { sections: vec![TextSection { value: text, style: TextStyle { color, font, font_size: size, }, }], alignment: TextAlignment { vertical: VerticalAlign::Center, horizontal: HorizontalAlign::Center, }, }, transform: Transform::from_xyz(0., 0., 1.), ..Default::default() } }
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It takes in parameter:

  • count: the neighboring bomb count to print
  • font: a asset Handle of our font
  • size: a text size

The colors are completely arbitrary.
Again, we put the z value of the Transform translation to 1. so the text is printed on top of the tile.

We can now move our tile spawning loop into a distinct function:

// lib.rs fn spawn_tiles( parent: &mut ChildBuilder, tile_map: &TileMap, size: f32, padding: f32, color: Color, bomb_image: Handle<Image>, font: Handle<Font>, ) { // Tiles for (y, line) in tile_map.iter().enumerate() { for (x, tile) in line.iter().enumerate() { let coordinates = Coordinates { x: x as u16, y: y as u16, }; let mut cmd = parent.spawn(); cmd.insert_bundle(SpriteBundle { sprite: Sprite { color, custom_size: Some(Vec2::splat(size - padding)), ..Default::default() }, transform: Transform::from_xyz( (x as f32 * size) + (size / 2.), (y as f32 * size) + (size / 2.), 1., ), ..Default::default() }) .insert(Name::new(format!("Tile ({}, {})", x, y))) .insert(coordinates); } } }
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  • Notice we now use a temporary cmd value for our entity builder*

We can now call it from our create_board startup system, in our with_children block after the background spawn:

// lib.rs // .. Self::spawn_tiles( parent, &tile_map, tile_size, options.tile_padding, Color::GRAY, bomb_image, font, );
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Then we complete our spawn_tiles function to add our bombs sprites and counter texts inside the double for loop:

// lib.rs use resources::tile::Tile; // .. match tile { // If the tile is a bomb we add the matching component and a sprite child Tile::Bomb => { cmd.insert(Bomb); cmd.with_children(|parent| { parent.spawn_bundle(SpriteBundle { sprite: Sprite { custom_size: Some(Vec2::splat(size - padding)), ..Default::default() }, transform: Transform::from_xyz(0., 0., 1.), texture: bomb_image.clone(), ..Default::default() }); }); } // If the tile is a bomb neighbour we add the matching component and a text child Tile::BombNeighbor(v) => { cmd.insert(BombNeighbor { count: *v }); cmd.with_children(|parent| { parent.spawn_bundle(Self::bomb_count_text_bundle( *v, font.clone(), size - padding, )); }); } Tile::Empty => (), } // ..
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Until now all tiles had identical components like Coordinates, Transform, Sprite, etc.
But now some tiles have:

  • A Bomb component and a child entity with the bomb sprite
  • A BombNeighbor component and a child entity with the counter text

We added a texture to the bomb sprite, what about the others?

By default, a white square texture is used if no texture is specified on SpriteBundle. In Part 9 we will see it in more detail.

Let's run our app and get our beautiful board:

Board

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Author: Félix de Maneville
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Published by Qongzi

Top comments (5)

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tomuxmon profile image
Tomas Dambrauskas • • Edited

When I run using "cargo run" assets are loaded correctly. But when I try to launch debugger with visual studio code it fails loading assets.
my configuration looks like this:

{ "type": "lldb", "request": "launch", "name": "Debug executable 'minesweeper-tutorial'", "cargo": { "args": [ "build", "--bin=minesweeper-tutorial", "--package=minesweeper-tutorial", "--features", "debug" ], "filter": { "name": "minesweeper-tutorial", "kind": "bin" } }, "args": [], "cwd": "${workspaceFolder}" }
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should "cwd" (program working directory) be changed to something else?

Oh and also had to change BoardPlugin build debug section to use registry instead to make it work.:

 #[cfg(feature = "debug")] { let mut registry = app .world .get_resource_or_insert_with(InspectableRegistry::default); // registering custom component to be able to edit it in inspector registry.register::<Coordinates>(); registry.register::<BombNeighbor>(); registry.register::<Bomb>(); registry.register::<Uncover>(); }
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tomuxmon profile image
Tomas Dambrauskas • • Edited

Had to add environment variable in launch json :

"env": { "CARGO_MANIFEST_DIR": "${workspaceFolder}" }
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a clue found in : docs.rs/bevy_asset/0.6.0/bevy_asse...

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qongzi profile image
Qongzi •

I don't use VS Code so I don't know about the issues with the built in debugger.

About the registry, you are using the old way of registering the components
Are you using the latest version of bevy_inspector_egui ? It should be 0.8.x.
Accessing the inspectable registry is no longer required

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tomuxmon profile image
Tomas Dambrauskas • • Edited

hmm. set the version in cargo to version = "~0.8". checked to see that version 0.8.2 is being downloaded. still had the same issue. Got panic:

thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', /home/tomas/.cargo/registry/src/github.com-1ecc6299db9ec823/bevy-inspector-egui-0.8.2/src/lib.rs:375:14
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bevy inspector egui panicked when unwrapping:

impl RegisterInspectable for App { fn register_inspectable<T: Inspectable + 'static>(&mut self) -> &mut Self { self.world .get_resource_mut::<InspectableRegistry>() .unwrap() // <-- panic here .register::<T>(); self } } //..
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also. it seems that order of adding world inspector plugin matters (somehow expecting it to be strictly declarative). If I register the plugin at the start like this:

let mut app = App::new(); // Debug hierarchy inspector #[cfg(feature = "debug")] app.add_plugin(WorldInspectorPlugin::new());
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I get no panic, but sadly I also do not get any world inspector plugin.
If I add the world inspector plugin just before the app run it ends up panicking.

 // Debug hierarchy inspector #[cfg(feature = "debug")] app.add_plugin(WorldInspectorPlugin::new()); app.run();
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but anyways... registry.register::<T>() work for me so I do not really care at this point :P. Thanks for your time!

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leonidv profile image
Leonid Vygovskiy •

github.com/leonidv/bevy-minesweepe... - full tutorial updated to 12.1. One chapter per commit.