1 files changed, 87 insertions, 0 deletions
diff --git a/src/sim/cell.rs b/src/sim/cell.rs
new file mode 100644
index 0000000..5a9fc1f
--- /dev/null
+++ b/src/sim/cell.rs
@@ -0,0 +1,87 @@
+use crate::{config::SETTLED_THRESOHLD, content::materials::MaterialId};
+
+#[derive(Clone, Copy)]
+pub struct Cell {
+    pub material: MaterialId,
+    pub flags: u8,
+    pub data: u16,
+}
+
+impl Cell {
+    // only update the cell if this matches the parity of the seqno
+    const FLAG_PARITY: u8 = 0b0000_0001;
+    // is this cell owned by an entity?
+    const FLAG_ENTITY_INTEGRATED: u8 = 0b0000_0010;
+    // how close is the cell to settling?
+    const MASK_SETTLED: u8 = 0b0001_1100;
+
+    #[inline]
+    pub fn parity(self) -> u8 {
+        self.flags & Self::FLAG_PARITY
+    }
+    #[inline]
+    pub fn flip_parity(&mut self) {
+        self.flags ^= Self::FLAG_PARITY;
+    }
+    #[inline]
+    pub fn match_parity(&mut self, seqno: u64) {
+        let parity = !seqno.is_multiple_of(2);
+        if parity {
+            self.flags |= Self::FLAG_PARITY;
+        } else {
+            self.flags &= !Self::FLAG_PARITY
+        }
+    }
+
+    #[inline]
+    pub fn entity_integrated(self) -> bool {
+        (self.flags & Self::FLAG_ENTITY_INTEGRATED) == Self::FLAG_ENTITY_INTEGRATED
+    }
+    #[inline]
+    pub fn set_entity_integrated(&mut self, entity_integrated: bool) {
+        if entity_integrated {
+            self.flags |= Self::FLAG_ENTITY_INTEGRATED
+        } else {
+            self.flags &= !Self::FLAG_ENTITY_INTEGRATED
+        }
+    }
+
+    #[inline]
+    pub fn settled(self) -> u8 {
+        (self.flags & Self::MASK_SETTLED) >> 2
+    }
+    #[inline]
+    fn set_settled(&mut self, settled: u8) {
+        debug_assert!(settled <= 7);
+        self.flags = (settled << 2) | (self.flags & !Self::MASK_SETTLED);
+    }
+    #[inline]
+    pub fn reset_settled(&mut self) {
+        self.flags &= !Self::MASK_SETTLED;
+    }
+
+    #[inline]
+    pub fn increment_settled(&mut self) {
+        let s = self.settled();
+        if s < SETTLED_THRESOHLD {
+            self.set_settled(s + 1);
+        }
+    }
+}
+
+impl Cell {
+    pub fn void() -> Cell {
+        Cell {
+            material: MaterialId::Void,
+            flags: 0,
+            data: 0,
+        }
+    }
+    pub fn from_material(material: MaterialId) -> Cell {
+        Cell {
+            material,
+            flags: 0,
+            data: 0,
+        }
+    }
+}