6726e40768
* adds Lua language support * makes the library generic, allowing for easy extension for more languages * small improvements and fixes
75 lines
1.7 KiB
Markdown
75 lines
1.7 KiB
Markdown
# Interacting with bevy in callbacks
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Every registered function is also just a regular Bevy system.
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That allows you to do anything you would do in a Bevy system.
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You could for example create a callback system function that prints names
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of all entities with `Player` component.
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```rust
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use bevy::prelude::*;
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use bevy_scriptum::prelude::*;
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use bevy_scriptum::runtimes::lua::prelude::*;
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#[derive(Component)]
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struct Player;
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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.add_scripting::<LuaRuntime>(|runtime| {
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runtime.add_function(
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String::from("print_player_names"),
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|players: Query<&Name, With<Player>>| {
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for player in &players {
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println!("player name: {}", player);
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}
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},
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);
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})
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.run();
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}
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```
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In script:
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```lua
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print_player_names()
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```
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You can use functions that interact with Bevy entities and resources and
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take arguments at the same time. It could be used for example to mutate a
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component.
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```rust
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use bevy::prelude::*;
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use bevy_scriptum::prelude::*;
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use bevy_scriptum::runtimes::lua::prelude::*;
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#[derive(Component)]
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struct Player {
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health: i32
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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_scripting::<LuaRuntime>(|runtime| {
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runtime.add_function(
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String::from("hurt_player"),
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|In((hit_value,)): In<(i32,)>, mut players: Query<&mut Player>| {
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let mut player = players.single_mut();
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player.health -= hit_value;
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},
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);
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})
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.run();
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}
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```
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And it could be called in script like:
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```lua
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hurt_player(5)
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```
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