Make single-activation traps work

src/components.rs

@@ -208,6 +208,9 @@ pub struct EntryTrigger {}
 #[derive(Component, Debug, Serialize, Deserialize, Clone)]
 pub struct EntityMoved {}
 
+#[derive(Component, Debug, Serialize, Deserialize, Clone)]
+pub struct SingleActivation {}
+
 // Serialization helper code. We need to implement ConvertSaveLoad for each type that contains an
 // Entity.
 

src/main.rs

@@ -520,6 +520,7 @@ fn main() -> rltk::BError {
         Hidden,
         EntryTrigger,
         EntityMoved,
+        SingleActivation,
     );
 
     gs.ecs.insert(SimpleMarkerAllocator::<SerializeMe>::new());

src/saveload_system.rs

@@ -82,6 +82,7 @@ pub fn save_game(ecs: &mut World) {
             Hidden,
             EntryTrigger,
             EntityMoved,
+            SingleActivation,
         );
     }
 
@@ -170,6 +171,7 @@ pub fn load_game(ecs: &mut World) {
             Hidden,
             EntryTrigger,
             EntityMoved,
+            SingleActivation,
         );
     }
 

src/spawner.rs

@@ -334,6 +334,7 @@ fn bear_trap(ecs: &mut World, x: i32, y: i32) {
         .with(Hidden {})
         .with(EntryTrigger {})
         .with(InflictsDamage { damage: 6 })
+        .with(SingleActivation {})
         .marked::<SimpleMarker<SerializeMe>>()
         .build();
 }

src/trigger_system.rs

@@ -1,5 +1,6 @@
 use crate::components::{
-    EntityMoved, EntryTrigger, Hidden, InflictsDamage, Name, Position, SufferDamage,
+    EntityMoved, EntryTrigger, Hidden, InflictsDamage, Name, Position, SingleActivation,
+    SufferDamage,
 };
 use crate::{game_log::GameLog, particle_system::ParticleBuilder, Map};
 use specs::prelude::*;
@@ -20,6 +21,7 @@ impl<'a> System<'a> for TriggerSystem {
         ReadStorage<'a, InflictsDamage>,
         WriteExpect<'a, ParticleBuilder>,
         WriteStorage<'a, SufferDamage>,
+        ReadStorage<'a, SingleActivation>,
     );
 
     fn run(&mut self, data: Self::SystemData) {
@@ -35,9 +37,11 @@ impl<'a> System<'a> for TriggerSystem {
             inflicts_damage,
             mut particle_builder,
             mut inflict_damage,
+            single_activation,
         ) = data;
 
         // Iterate the entities that moved and their final position
+        let mut remove_entities: Vec<Entity> = Vec::new();
         for (entity, mut _entity_moved, pos) in (&entities, &mut entity_moved, &position).join() {
             let idx = map.xy_idx(pos.x, pos.y);
 
@@ -72,12 +76,24 @@ impl<'a> System<'a> for TriggerSystem {
                                     damage.damage,
                                 );
                             }
+
+                            // If it is single activation, it needs to be removed
+                            if let Some(_sa) = single_activation.get(*entity_id) {
+                                remove_entities.push(*entity_id);
+                            }
                         }
                     }
                 }
             }
         }
 
+        // Remove any single activation traps
+        for trap in remove_entities.iter() {
+            entities
+                .delete(*trap)
+                .expect("Unable to remove single activation entity");
+        }
+
         // Remove all entity movement markers
         entity_moved.clear();
     }