feat(engine): add support for drawing objects as a bundle

1 files changed, 35 insertions, 0 deletions

diff --git a/engine/src/draw_flags.rs b/engine/src/draw_flags.rs
index c8c11c9..1352fe2 100644
--- a/engine/src/draw_flags.rs
+++ b/engine/src/draw_flags.rs
@@ -1,7 +1,11 @@
+use std::sync::atomic::{AtomicUsize, Ordering};
+
 use ecs::Component;
 
 use crate::util::builder;
 
+static CURRENT_BUNDLE_ID: AtomicUsize = AtomicUsize::new(0);
+
 builder! {
 /// Flags for how a object should be drawn.
 #[builder(name = Builder, derives = (Debug, Default, Clone))]
@@ -47,3 +51,34 @@ pub enum PolygonModeFace
     #[default]
     FrontAndBack,
 }
+
+/// Metadata for how a object should be drawn together with other objects.
+#[derive(Debug, Clone, Component)]
+pub struct DrawingBundled
+{
+    pub bundle_id: DrawingBundleId,
+    pub order: usize,
+}
+
+/// The ID of a object drawing bundle.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct DrawingBundleId
+{
+    inner: usize,
+}
+
+impl DrawingBundleId
+{
+    /// Creates a new unique bundle ID.
+    pub fn new() -> Self
+    {
+        Self {
+            inner: CURRENT_BUNDLE_ID.fetch_add(1, Ordering::Relaxed),
+        }
+    }
+
+    pub fn inner(&self) -> usize
+    {
+        self.inner
+    }
+}