ensuring we remove entities from the SpatialMap when they die

src/damage_system.rs

@@ -56,6 +56,10 @@ impl<'a> System<'a> for DamageSystem {
                     if let Some(xp_value) = gives_xp {
                         xp_gain += xp_value.amount;
                     }
+                    if let Some(pos) = pos {
+                        let idx = map.xy_idx(pos.x, pos.y);
+                        crate::spatial::remove_entity(entity, idx);
+                    }
                 }
             }
         }

src/map_indexing_system.rs

@@ -1,19 +1,33 @@
-use super::{spatial, BlocksTile, Map, Position};
+use super::{spatial, BlocksTile, Map, Pools, Position};
 use specs::prelude::*;
 
 pub struct MapIndexingSystem {}
 
 impl<'a> System<'a> for MapIndexingSystem {
-    type SystemData = (ReadExpect<'a, Map>, ReadStorage<'a, Position>, ReadStorage<'a, BlocksTile>, Entities<'a>);
+    type SystemData = (
+        ReadExpect<'a, Map>,
+        ReadStorage<'a, Position>,
+        ReadStorage<'a, BlocksTile>,
+        Entities<'a>,
+        ReadStorage<'a, Pools>,
+    );
 
     fn run(&mut self, data: Self::SystemData) {
-        let (map, position, blockers, entities) = data;
+        let (map, position, blockers, entities, pools) = data;
 
         spatial::clear();
         spatial::populate_blocked_from_map(&*map);
         for (entity, position) in (&entities, &position).join() {
-            let idx = map.xy_idx(position.x, position.y);
-            spatial::index_entity(entity, idx, blockers.get(entity).is_some());
+            let mut alive = true;
+            if let Some(pools) = pools.get(entity) {
+                if pools.hit_points.current < 1 {
+                    alive = false;
+                }
+            }
+            if alive {
+                let idx = map.xy_idx(position.x, position.y);
+                spatial::index_entity(entity, idx, blockers.get(entity).is_some());
+            }
         }
     }
 }

src/spatial/mod.rs

@@ -56,6 +56,19 @@ pub fn index_entity(entity: Entity, idx: usize, blocks_tile: bool) {
     }
 }
 
+/// Removes an entity from SpatialMap tilecontent.
+pub fn remove_entity(entity: Entity, idx: usize) {
+    let mut lock = SPATIAL_MAP.lock().unwrap();
+    lock.tile_content[idx].retain(|(e, _)| *e != entity);
+    let mut from_blocked = false;
+    lock.tile_content[idx].iter().for_each(|(_, blocks)| {
+        if *blocks {
+            from_blocked = true;
+        }
+    });
+    lock.blocked[idx].1 = from_blocked;
+}
+
 /// Returns is_empty on a given tile content idx.
 pub fn has_tile_content(idx: usize) -> bool {
     let lock = SPATIAL_MAP.lock().unwrap();