From 697cd10958117de9c1ddaf92edcc64950e35fb07 Mon Sep 17 00:00:00 2001
From: "squi.dev" <me@squi.dev>
Date: Fri, 21 Aug 2026 19:00:36 +0200
Subject: [PATCH] maskset (untested version)

---
 src/lib.rs     |  2 ++
 src/maskset.rs | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 src/maskset.rs

diff --git a/src/lib.rs b/src/lib.rs
index aaad6f8..3c3797b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,3 +5,5 @@ extern crate alloc;
 
 pub mod blob;
 pub mod entity;
+
+pub mod maskset;
diff --git a/src/maskset.rs b/src/maskset.rs
new file mode 100644
index 0000000..b23d570
--- /dev/null
+++ b/src/maskset.rs
@@ -0,0 +1,42 @@
+use alloc::vec::Vec;
+
+#[repr(C)]
+pub struct Mask(pub u32, pub u32);
+
+pub struct MaskSet {
+    masks: Vec<Mask>,
+}
+
+impl MaskSet {
+    pub fn contains(&self, Mask(target, test): Mask) -> bool {
+        for Mask(idx, truth) in &self.masks {
+            if *idx == target && ((truth & test) == 1) {
+                return true;
+            }
+        }
+        false
+    }
+
+    pub fn insert(&mut self, Mask(target, value): Mask) {
+        for Mask(idx, truth) in &mut self.masks {
+            if *idx == target {
+                *truth |= value;
+                return;
+            }
+        }
+        self.masks.push(Mask(target, value));
+        self.masks.sort_by_key(|m| m.0);
+    }
+
+    pub fn remove(&mut self, Mask(target, test): Mask) {
+        for (i, Mask(idx, truth)) in self.masks.iter_mut().enumerate() {
+            if *idx == target && ((*truth & test) == 1) {
+                *truth ^= test;
+                if *truth == 0 {
+                    self.masks.remove(i);
+                }
+                return;
+            }
+        }
+    }
+}
-- 
2.51.2