add ruby example

Cargo.toml

@@ -154,6 +154,11 @@ name = "function_return_value_lua"
 path = "examples/lua/function_return_value.rs"
 required-features = ["lua"]
 
+[[example]]
+name = "call_function_from_rust_ruby"
+path = "examples/ruby/call_function_from_rust.rs"
+required-features = ["ruby"]
+
 [dev-dependencies]
 tracing-subscriber = "0.3.18"
 mlua = { version = "0.9.8", features = ["luajit", "vendored", "send"] }

assets/examples/ruby/call_function_from_rust.rb

@@ -0,0 +1,13 @@
+$my_state = {
+  iterations: 0,
+}
+
+def on_update
+  $my_state[:iterations] += 1
+  puts("on_update called #{$my_state[:iterations]} times")
+
+  if $my_state[:iterations] >= 10
+    print("calling quit");
+    quit()
+  end
+end

examples/ruby/call_function_from_rust.rs

@@ -0,0 +1,33 @@
+use bevy::{app::AppExit, prelude::*};
+use bevy_scriptum::prelude::*;
+use bevy_scriptum::runtimes::ruby::prelude::*;
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins)
+        .add_systems(Startup, startup)
+        .add_systems(Update, call_ruby_on_update_from_rust)
+        .add_scripting::<RubyRuntime>(|runtime| {
+            runtime.add_function(String::from("quit"), |mut exit: EventWriter<AppExit>| {
+                exit.write(AppExit::Success);
+            });
+        })
+        .run();
+}
+
+fn startup(mut commands: Commands, assets_server: Res<AssetServer>) {
+    commands.spawn(Script::<RubyScript>::new(
+        assets_server.load("examples/ruby/call_function_from_rust.rb"),
+    ));
+}
+
+fn call_ruby_on_update_from_rust(
+    mut scripted_entities: Query<(Entity, &mut RubyScriptData)>,
+    scripting_runtime: ResMut<RubyRuntime>,
+) {
+    for (entity, mut script_data) in &mut scripted_entities {
+        scripting_runtime
+            .call_fn("on_update", &mut script_data, entity, ())
+            .unwrap();
+    }
+}