Complete Chapter 2.5

src/components.rs

@@ -24,3 +24,11 @@ pub struct Viewshed {
     pub range: i32,
     pub dirty: bool,
 }
+
+#[derive(Component)]
+pub struct Monster {}
+
+#[derive(Component)]
+pub struct Name {
+    pub name: String,
+}

src/main.rs

@@ -1,4 +1,4 @@
-use rltk::{GameState, Rltk, RGB};
+use rltk::{GameState, Point, Rltk, RGB};
 use specs::prelude::*;
 
 mod components;
@@ -10,11 +10,20 @@ use player::*;
 mod rect;
 mod visibility_system;
 use visibility_system::VisibilitySystem;
+mod monster_ai_system;
+use monster_ai_system::*;
 
 pub use rect::Rect;
 
+#[derive(PartialEq, Copy, Clone)]
+pub enum RunState {
+    Paused,
+    Running,
+}
+
 pub struct State {
-    ecs: World,
+    pub ecs: World,
+    pub runstate: RunState,
 }
 
 impl State {
@@ -22,6 +31,9 @@ impl State {
         let mut vis = VisibilitySystem {};
         vis.run_now(&self.ecs);
 
+        let mut mob = MonsterAI {};
+        mob.run_now(&self.ecs);
+
         self.ecs.maintain();
     }
 }
@@ -30,8 +42,12 @@ impl GameState for State {
     fn tick(&mut self, ctx: &mut Rltk) {
         ctx.cls();
 
-        player_input(self, ctx);
-        self.run_systems();
+        if self.runstate == RunState::Running {
+            self.run_systems();
+            self.runstate = RunState::Paused;
+        } else {
+            self.runstate = player_input(self, ctx);
+        }
 
         draw_map(&self.ecs, ctx);
 
@@ -55,23 +71,44 @@ fn main() -> rltk::BError {
         .with_title("Roguelike Tutorial")
         .build()?;
 
-    let mut gs = State { ecs: World::new() };
+    let mut gs = State {
+        ecs: World::new(),
+        runstate: RunState::Running,
+    };
 
     gs.ecs.register::<Position>();
     gs.ecs.register::<Renderable>();
     gs.ecs.register::<Player>();
     gs.ecs.register::<Viewshed>();
+    gs.ecs.register::<Monster>();
+    gs.ecs.register::<Name>();
 
     let map: Map = Map::new_map_rooms_and_corridors();
     let (player_x, player_y) = map.rooms[0].center();
 
-    for room in map.rooms.iter().skip(1) {
+    let mut rng = rltk::RandomNumberGenerator::new();
+    for (i, room) in map.rooms.iter().skip(1).enumerate() {
         let (x, y) = room.center();
+
+        let glyph: rltk::FontCharType;
+        let name: String;
+        let roll = rng.roll_dice(1, 2);
+        match roll {
+            1 => {
+                glyph = rltk::to_cp437('g');
+                name = "Goblin".to_string();
+            }
+            _ => {
+                glyph = rltk::to_cp437('o');
+                name = "Orc".to_string();
+            }
+        }
+
         gs.ecs
             .create_entity()
             .with(Position { x, y })
             .with(Renderable {
-                glyph: rltk::to_cp437('g'),
+                glyph,
                 fg: RGB::named(rltk::RED),
                 bg: RGB::named(rltk::BLACK),
             })
@@ -80,6 +117,10 @@ fn main() -> rltk::BError {
                 range: 8,
                 dirty: true,
             })
+            .with(Monster {})
+            .with(Name {
+                name: format!("{} #{}", &name, i),
+            })
             .build();
     }
 
@@ -100,9 +141,13 @@ fn main() -> rltk::BError {
             range: 8,
             dirty: true,
         })
+        .with(Name {
+            name: "Player".to_string(),
+        })
         .build();
 
     gs.ecs.insert(map);
+    gs.ecs.insert(Point::new(player_x, player_y));
 
     rltk::main_loop(context, gs)
 }

src/monster_ai_system.rs

@@ -0,0 +1,24 @@
+use super::{Monster, Name, Viewshed};
+use rltk::{console, Point};
+use specs::prelude::*;
+
+pub struct MonsterAI {}
+
+impl<'a> System<'a> for MonsterAI {
+    type SystemData = (
+        ReadExpect<'a, Point>,
+        ReadStorage<'a, Viewshed>,
+        ReadStorage<'a, Monster>,
+        ReadStorage<'a, Name>,
+    );
+
+    fn run(&mut self, data: Self::SystemData) {
+        let (player_pos, viewshed, monster, name) = data;
+
+        for (viewshed, _monster, name) in (&viewshed, &monster, &name).join() {
+            if viewshed.visible_tiles.contains(&*player_pos) {
+                console::log(format!("{} shouts insults", name.name));
+            }
+        }
+    }
+}

src/player.rs

@@ -1,5 +1,6 @@
 use super::{Map, Player, Position, State, TileType, Viewshed};
-use rltk::{Rltk, VirtualKeyCode};
+use crate::RunState;
+use rltk::{Point, Rltk, VirtualKeyCode};
 use specs::prelude::*;
 use std::cmp::{max, min};
 
@@ -15,15 +16,19 @@ pub fn try_move_player(delta_x: i32, delta_y: i32, ecs: &mut World) {
             pos.x = min(79, max(0, pos.x + delta_x));
             pos.y = min(49, max(0, pos.y + delta_y));
 
+            let mut ppos = ecs.write_resource::<Point>();
+            ppos.x = pos.x;
+            ppos.y = pos.y;
+
             viewshed.dirty = true;
         }
     }
 }
 
-pub fn player_input(gs: &mut State, ctx: &mut Rltk) {
+pub fn player_input(gs: &mut State, ctx: &mut Rltk) -> RunState {
     // Player movement
     match ctx.key {
-        None => {} // Nothing happened
+        None => return RunState::Paused, // Nothing happened
         Some(key) => match key {
             VirtualKeyCode::Left | VirtualKeyCode::Numpad4 | VirtualKeyCode::H => {
                 try_move_player(-1, 0, &mut gs.ecs)
@@ -41,7 +46,9 @@ pub fn player_input(gs: &mut State, ctx: &mut Rltk) {
                 try_move_player(0, 1, &mut gs.ecs)
             }
 
-            _ => {}
+            _ => return RunState::Paused,
         },
     }
+
+    RunState::Running
 }