Add a basic hidden trap mechanism

src/components.rs

@@ -199,6 +199,15 @@ pub struct ProvidesFood {}
 #[derive(Component, Debug, Serialize, Deserialize, Clone)]
 pub struct MagicMapper {}
 
+#[derive(Component, Debug, Serialize, Deserialize, Clone)]
+pub struct Hidden {}
+
+#[derive(Component, Debug, Serialize, Deserialize, Clone)]
+pub struct EntryTrigger {}
+
+#[derive(Component, Debug, Serialize, Deserialize, Clone)]
+pub struct EntityMoved {}
+
 // Serialization helper code. We need to implement ConvertSaveLoad for each type that contains an
 // Entity.
 

src/gui.rs

@@ -1,7 +1,7 @@
 use crate::components::{
     CombatStats, HungerClock, HungerState, InBackpack, Name, Player, Position, Viewshed,
 };
-use crate::{game_log::GameLog, rex_assets::RexAssets, Equipped, Map, RunState, State};
+use crate::{game_log::GameLog, rex_assets::RexAssets, Equipped, Hidden, Map, RunState, State};
 use rltk::{Point, Rltk, VirtualKeyCode, RGB};
 use specs::prelude::*;
 
@@ -98,6 +98,7 @@ fn draw_tooltips(ecs: &World, ctx: &mut Rltk) {
     let map = ecs.fetch::<Map>();
     let names = ecs.read_storage::<Name>();
     let positions = ecs.read_storage::<Position>();
+    let hidden = ecs.read_storage::<Hidden>();
 
     let mouse_pos = ctx.mouse_pos();
     if mouse_pos.0 >= map.width || mouse_pos.1 >= map.height {
@@ -105,7 +106,7 @@ fn draw_tooltips(ecs: &World, ctx: &mut Rltk) {
     }
     let mut tooltip: Vec<String> = Vec::new();
 
-    for (name, position) in (&names, &positions).join() {
+    for (name, position, _hidden) in (&names, &positions, !&hidden).join() {
         let idx = map.xy_idx(position.x, position.y);
         if position.x == mouse_pos.0 && position.y == mouse_pos.1 && map.visible_tiles[idx] {
             tooltip.push(name.name.to_string());

src/main.rs

@@ -19,6 +19,7 @@ mod rect;
 mod rex_assets;
 pub mod saveload_system;
 mod spawner;
+mod trigger_system;
 mod visibility_system;
 
 use crate::inventory_system::ItemRemoveSystem;
@@ -85,6 +86,9 @@ impl State {
         let mut mob = MonsterAI {};
         mob.run_now(&self.ecs);
 
+        let mut triggers = trigger_system::TriggerSystem {};
+        triggers.run_now(&self.ecs);
+
         let mut mapindex = MapIndexingSystem {};
         mapindex.run_now(&self.ecs);
 
@@ -129,17 +133,19 @@ impl GameState for State {
 
         match newrunstate {
             RunState::MainMenu { .. } => {}
+            RunState::GameOver { .. } => {}
             _ => {
                 // Draw the UI
                 draw_map(&self.ecs, ctx);
                 {
                     let positions = self.ecs.read_storage::<Position>();
                     let renderables = self.ecs.read_storage::<Renderable>();
+                    let hidden = self.ecs.read_storage::<Hidden>();
                     let map = self.ecs.fetch::<Map>();
 
-                    let mut data: Vec<_> = (&positions, &renderables).join().collect();
+                    let mut data: Vec<_> = (&positions, &renderables, !&hidden).join().collect();
                     data.sort_by(|&a, &b| b.1.render_order.cmp(&a.1.render_order));
-                    for (pos, render) in data.iter() {
+                    for (pos, render, _hidden) in data.iter() {
                         let idx = map.xy_idx(pos.x, pos.y);
 
                         if map.visible_tiles[idx] {
@@ -511,6 +517,9 @@ fn main() -> rltk::BError {
         HungerClock,
         ProvidesFood,
         MagicMapper,
+        Hidden,
+        EntryTrigger,
+        EntityMoved,
     );
 
     gs.ecs.insert(SimpleMarkerAllocator::<SerializeMe>::new());

src/monster_ai_system.rs

@@ -1,5 +1,5 @@
 use crate::components::{Confusion, Monster, Position, Viewshed, WantsToMelee};
-use crate::{particle_system::ParticleBuilder, Map, RunState};
+use crate::{particle_system::ParticleBuilder, EntityMoved, Map, RunState};
 use rltk::{Point, RGB};
 use specs::prelude::*;
 
@@ -19,6 +19,7 @@ impl<'a> System<'a> for MonsterAI {
         WriteStorage<'a, WantsToMelee>,
         WriteStorage<'a, Confusion>,
         WriteExpect<'a, ParticleBuilder>,
+        WriteStorage<'a, EntityMoved>,
     );
 
     fn run(&mut self, data: Self::SystemData) {
@@ -34,6 +35,7 @@ impl<'a> System<'a> for MonsterAI {
             mut wants_to_melee,
             mut confused,
             mut particle_builder,
+            mut entity_moved,
         ) = data;
 
         if *runstate != RunState::MonsterTurn {
@@ -91,6 +93,10 @@ impl<'a> System<'a> for MonsterAI {
                         pos.x = path.steps[1] as i32 % map.width;
                         pos.y = path.steps[1] as i32 / map.width;
 
+                        entity_moved
+                            .insert(entity, EntityMoved {})
+                            .expect("Unable to add EntityMoved flag to monster");
+
                         idx = map.xy_idx(pos.x, pos.y);
                         map.blocked[idx] = true;
                         viewshed.dirty = true;

src/player.rs

@@ -1,6 +1,6 @@
 use crate::components::{
-    CombatStats, HungerClock, HungerState, Item, Monster, Player, Position, Viewshed, WantsToMelee,
-    WantsToPickupItem,
+    CombatStats, EntityMoved, HungerClock, HungerState, Item, Monster, Player, Position, Viewshed,
+    WantsToMelee, WantsToPickupItem,
 };
 use crate::{game_log::GameLog, Map, RunState, State, TileType};
 use rltk::{Point, Rltk, VirtualKeyCode};
@@ -15,6 +15,7 @@ pub fn try_move_player(delta_x: i32, delta_y: i32, ecs: &mut World) {
     let combat_stats = ecs.read_storage::<CombatStats>();
     let map = ecs.fetch::<Map>();
     let mut wants_to_melee = ecs.write_storage::<WantsToMelee>();
+    let mut entity_moved = ecs.write_storage::<EntityMoved>();
 
     for (entity, _player, pos, viewshed) in
         (&entities, &players, &mut positions, &mut viewsheds).join()
@@ -45,6 +46,9 @@ pub fn try_move_player(delta_x: i32, delta_y: i32, ecs: &mut World) {
         if !map.blocked[destination_idx] {
             pos.x = min(79, max(0, pos.x + delta_x));
             pos.y = min(49, max(0, pos.y + delta_y));
+            entity_moved
+                .insert(entity, EntityMoved {})
+                .expect("Failed to add EntityMoved flag to player");
 
             viewshed.dirty = true;
             let mut ppos = ecs.write_resource::<Point>();

src/saveload_system.rs

@@ -79,6 +79,9 @@ pub fn save_game(ecs: &mut World) {
             HungerClock,
             ProvidesFood,
             MagicMapper,
+            Hidden,
+            EntryTrigger,
+            EntityMoved,
         );
     }
 
@@ -164,6 +167,9 @@ pub fn load_game(ecs: &mut World) {
             HungerClock,
             ProvidesFood,
             MagicMapper,
+            Hidden,
+            EntryTrigger,
+            EntityMoved,
         );
     }
 

src/spawner.rs

@@ -51,6 +51,7 @@ fn room_table(map_depth: i32) -> RandomTable {
         .add("Tower Shield", map_depth - 1)
         .add("Rations", 10)
         .add("Magic Mapping Scroll", 2)
+        .add("Bear Trap", 2)
 }
 
 /// fills a room with stuff!
@@ -101,6 +102,7 @@ pub fn spawn_room(ecs: &mut World, room: &Rect, map_depth: i32) {
             "Tower Shield" => tower_shield(ecs, x, y),
             "Rations" => rations(ecs, x, y),
             "Magic Mapping Scroll" => magic_mapping_scroll(ecs, x, y),
+            "Bear Trap" => bear_trap(ecs, x, y),
             _ => {}
         }
     }
@@ -318,3 +320,20 @@ fn magic_mapping_scroll(ecs: &mut World, x: i32, y: i32) {
         .marked::<SimpleMarker<SerializeMe>>()
         .build();
 }
+
+fn bear_trap(ecs: &mut World, x: i32, y: i32) {
+    ecs.create_entity()
+        .with(Position { x, y })
+        .with(Renderable {
+            glyph: rltk::to_cp437('^'),
+            fg: RGB::named(rltk::RED),
+            bg: RGB::named(rltk::BLACK),
+            render_order: 2,
+        })
+        .with(Name::from("Bear Trap"))
+        .with(Hidden {})
+        .with(EntryTrigger {})
+        .with(InflictsDamage { damage: 6 })
+        .marked::<SimpleMarker<SerializeMe>>()
+        .build();
+}

src/trigger_system.rs

@@ -0,0 +1,84 @@
+use crate::components::{
+    EntityMoved, EntryTrigger, Hidden, InflictsDamage, Name, Position, SufferDamage,
+};
+use crate::{game_log::GameLog, particle_system::ParticleBuilder, Map};
+use specs::prelude::*;
+
+pub struct TriggerSystem {}
+
+impl<'a> System<'a> for TriggerSystem {
+    #[allow(clippy::type_complexity)]
+    type SystemData = (
+        ReadExpect<'a, Map>,
+        WriteStorage<'a, EntityMoved>,
+        ReadStorage<'a, Position>,
+        ReadStorage<'a, EntryTrigger>,
+        WriteStorage<'a, Hidden>,
+        ReadStorage<'a, Name>,
+        Entities<'a>,
+        WriteExpect<'a, GameLog>,
+        ReadStorage<'a, InflictsDamage>,
+        WriteExpect<'a, ParticleBuilder>,
+        WriteStorage<'a, SufferDamage>,
+    );
+
+    fn run(&mut self, data: Self::SystemData) {
+        let (
+            map,
+            mut entity_moved,
+            position,
+            entry_trigger,
+            mut hidden,
+            names,
+            entities,
+            mut log,
+            inflicts_damage,
+            mut particle_builder,
+            mut inflict_damage,
+        ) = data;
+
+        // Iterate the entities that moved and their final position
+        for (entity, mut _entity_moved, pos) in (&entities, &mut entity_moved, &position).join() {
+            let idx = map.xy_idx(pos.x, pos.y);
+
+            for entity_id in map.tile_content[idx].iter() {
+                // Do not bother to check yourself for being a trap!
+                if entity != *entity_id {
+                    match entry_trigger.get(*entity_id) {
+                        None => {}
+                        Some(_trigger) => {
+                            // We triggered it
+                            if let Some(name) = names.get(*entity_id) {
+                                log.append(format!("{} triggers!", &name.name));
+                            }
+
+                            // The trap is no longer hidden
+                            hidden.remove(*entity_id);
+
+                            // If the trap is damage inflicting, do it
+                            if let Some(damage) = inflicts_damage.get(*entity_id) {
+                                particle_builder.request(
+                                    pos.x,
+                                    pos.y,
+                                    rltk::RGB::named(rltk::ORANGE),
+                                    rltk::RGB::named(rltk::BLACK),
+                                    rltk::to_cp437('‼'),
+                                    200.0,
+                                );
+
+                                SufferDamage::new_damage(
+                                    &mut inflict_damage,
+                                    entity,
+                                    damage.damage,
+                                );
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        // Remove all entity movement markers
+        entity_moved.clear();
+    }
+}