render_plugin: Add first SubApp and default schedules

crates/engine_render/src/lib.rs

@@ -0,0 +1,65 @@
+use bevy_app::{App, AppLabel, Last, Plugin, SubApp};
+use bevy_ecs::{
+    schedule::{IntoScheduleConfigs, Schedule, ScheduleLabel, SystemSet},
+    system::Commands,
+};
+
+#[derive(Debug, Hash, PartialEq, Eq, Clone, SystemSet)]
+pub enum RenderSystems {
+    Prepare,
+    Queue,
+    Render,
+    Present,
+}
+
+#[derive(ScheduleLabel, Debug, Hash, PartialEq, Eq, Clone, Default)]
+pub struct Render;
+
+impl Render {
+    pub fn base_schedule() -> Schedule {
+        use RenderSystems::*;
+
+        let mut schedule = Schedule::new(Self);
+
+        schedule.configure_sets((Prepare, Queue, Render, Present).chain());
+
+        schedule
+    }
+}
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, AppLabel)]
+pub struct RenderApp;
+
+pub struct RenderPlugin;
+
+impl Plugin for RenderPlugin {
+    fn build(&self, app: &mut App) {
+        let mut render_app = SubApp::new();
+        render_app.update_schedule = Some(Render.intern());
+
+        render_app.add_schedule(Render::base_schedule());
+
+        render_app.add_systems(Render, test_prepare.in_set(RenderSystems::Prepare));
+        render_app.add_systems(Render, test_queue.in_set(RenderSystems::Queue));
+        render_app.add_systems(Render, test_render.in_set(RenderSystems::Render));
+        render_app.add_systems(Render, test_present.in_set(RenderSystems::Present));
+
+        app.insert_sub_app(RenderApp, render_app);
+    }
+}
+
+fn test_prepare(mut commands: Commands) {
+    log::info!("test_prepare");
+}
+
+fn test_queue(mut commands: Commands) {
+    log::info!("test_queue");
+}
+
+fn test_render(mut commands: Commands) {
+    log::info!("test_render");
+}
+
+fn test_present(mut commands: Commands) {
+    log::info!("test_present");
+}