monsters move and attack the player

src/game.rs

@@ -179,11 +179,11 @@ impl Game {
         }
     }
     /// updates the player's current level. This will remove collected artifacts and dead monsters.
-    pub fn update_level(&mut self) {
+    pub fn update_level(&mut self, ticks: u128) {
         let player_pos = &self.player.get_immutable_position();
         let player_level = player_pos.get_level();
         let level = &mut self.levels[player_level];
-        level.update();
+        level.update(ticks, &mut self.player);
     }
 }
 

src/level.rs

@@ -9,6 +9,8 @@ use crate::monster::Monster;
 use crate::player::Player;
 use crate::position::HasPosition;
 use crate::position::Position;
+use rand::Rng;
+use rand::rngs::ThreadRng;
 
 pub const LEVEL_WIDTH: usize = 50;
 pub const LEVEL_HEIGHT: usize = 25;
@@ -34,6 +36,7 @@ pub struct Level {
     pub(crate) start: (usize, usize),
     /// the position of the end in the level (either stair down or end point)
     pub(crate) end: (usize, usize),
+    pub(crate) rng: ThreadRng,
 }
 
 impl Level {
@@ -108,7 +111,7 @@ impl Level {
             }
         }
     }
-    pub fn update(&mut self) {
+    pub fn update(&mut self, ticks: u128, player: &mut Player) {
         for (index, a) in &mut self.artifacts.iter().enumerate() {
             if a.was_collected() {
                 self.artifacts.remove(index);
@@ -122,17 +125,43 @@ impl Level {
             }
         }
         for index in 0..self.monsters.len() {
-            if self.can_monster_move(self.monsters[index].as_ref(), 0, 1) {
-                self.monsters[index].get_position().change(0, 1);
-            } else if self.can_monster_move(self.monsters[index].as_ref(), 0, -1) {
-                self.monsters[index].get_position().change(0, -1);
+            if ticks % self.monsters[index].get_ticks_between_steps() != 0 {
+                continue;
+            }
+            loop {
+                // calculate the direction the monster will try to walk
+                let (dx, dy) = match self.rng.gen_range(0..5) {
+                    1 => { (1, 0) }
+                    2 => { (-1, 0) }
+                    3 => { (0, 1) }
+                    4 => { (0, -1) }
+                    _ => { (0, 0) }
+                };
+                if self.can_monster_move(self.monsters[index].as_ref(), dx, dy) {
+                    let (new_x, new_y) = self.monsters[index].get_position().change(dx, dy);
+                    if player.get_immutable_position().get_x() == new_x && player.get_immutable_position().get_y() == new_y {
+                        self.monsters[index].decrease_life(1);
+                        player.change_life(-1);
+                    }
+                    break;
+                }
             }
         }
     }
+
     pub fn can_monster_move(&self, agent: &dyn Monster, dx: i16, dy: i16) -> bool {
         let agent_pos = agent.get_immutable_position();
         let new_x: usize = (agent_pos.get_x() as i16 + dx) as usize;
         let new_y: usize = (agent_pos.get_y() as i16 + dy) as usize;
+
+        if new_x < 0 || new_y < 0 || new_x >= LEVEL_WIDTH || new_y >= LEVEL_HEIGHT {
+            return false;
+        }
+
+        for index in 0..self.monsters.len() {
+            let pos = self.monsters[index].get_immutable_position();
+            if pos.get_x() == new_x && pos.get_y() == new_y { return false; }
+        }
         self.structure[new_x][new_y] != StructureElement::Wall
     }
     pub fn can_player_move(&self, agent: &Player, dx: i16, dy: i16) -> bool {
@@ -157,6 +186,7 @@ impl Level {
             artifacts: Vec::with_capacity(10),
             start: (0, 0),
             end: (0, 0),
+            rng: rand::thread_rng(),
         }
     }
     #[cfg(test)]

src/level_generator.rs

@@ -344,6 +344,7 @@ impl LevelGenerator {
             artifacts,
             start: (start_x, start_y),
             end: (end_x, end_y),
+            rng: rand::thread_rng(),
         }
     }
 }

src/main.rs

@@ -1,5 +1,6 @@
 use std::io::Result;
 use std::io::stdout;
+use std::time::Instant;
 
 use crossterm::{
     event::{self, KeyCode, KeyEventKind},
@@ -30,6 +31,9 @@ mod level_generator;
 mod artifacts;
 mod monster;
 
+/// length of a game frame in ms
+pub const FRAME_LENGTH: u64 = 100;
+
 //
 fn main() -> Result<()> {
     let mut game = Game::new(Player::new(realname().as_str(), 10));
@@ -39,6 +43,8 @@ fn main() -> Result<()> {
     let mut terminal = Terminal::new(CrosstermBackend::new(stdout()))?;
     terminal.clear()?;
 
+    let start_time = Instant::now();
+    let mut ticks = 0;
     loop {
         terminal.draw(|frame| {
             let mut area = frame.size();
@@ -57,7 +63,7 @@ fn main() -> Result<()> {
                     .block(block)
                     .wrap(Wrap { trim: true });
                 frame.render_widget(paragraph, area);
-                return
+                return;
             }
 
             if area.width > 80 {
@@ -96,7 +102,7 @@ fn main() -> Result<()> {
                 stats_area,
             );
         })?;
-        if event::poll(std::time::Duration::from_millis(100))? {
+        if event::poll(std::time::Duration::from_millis(FRAME_LENGTH))? {
             if let event::Event::Key(key) = event::read()? {
                 if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
                     break;
@@ -117,11 +123,13 @@ fn main() -> Result<()> {
                 }
             }
         }
-        game.update_level();
+        game.update_level(ticks);
         if game.get_game_state() != GameState::RUNNING {
             break;
         }
+        ticks += 1;
     }
+    let playtime = start_time.elapsed();
     loop {
         let _ = terminal.draw(|frame| {
             let mut area = frame.size();
@@ -151,6 +159,7 @@ fn main() -> Result<()> {
             };
             text += format!("\nYou gained {} experience.", game.get_player().get_experience()).as_str();
             text += format!("\nYou collected {} gold.", game.get_player().get_gold()).as_str();
+            text += format!("\nYou played {} seconds.", playtime.as_secs()).as_str();
             let paragraph = Paragraph::new(text).block(block).wrap(Wrap { trim: true });
             frame.render_widget(paragraph, area);
         });

src/monster.rs

@@ -8,8 +8,7 @@ pub trait Monster: HasPosition {
     fn decrease_life(&mut self, by: usize);
     // fn get_immutable_position(&self) -> &Position;
     fn get_experience_gain(&self) -> usize;
-    // #[cfg(test)]
-    // fn get_position(&mut self) -> &mut Position;
+    fn get_ticks_between_steps(&self) -> u128;
     #[cfg(test)]
     fn get_life(&self) -> usize;
 }
@@ -23,6 +22,8 @@ macro_rules! default_monster {
             fn decrease_life(&mut self, by: usize) {
                 self.life = self.life.saturating_sub(by);
             }
+            fn get_ticks_between_steps(&self) -> u128 { self.ticks_between_steps }
+
             #[cfg(test)]
             fn get_life(&self) -> usize { self.life }
         }
@@ -43,6 +44,7 @@ pub struct Rat {
     symbol: String,
     color: Color,
     experience_gain: usize,
+    ticks_between_steps: u128,
 }
 
 impl Rat {
@@ -53,6 +55,7 @@ impl Rat {
             symbol: String::from("R"),
             color: Color::Black,
             experience_gain: 5,
+            ticks_between_steps: 5,
         }
     }
 }
@@ -64,6 +67,7 @@ pub struct Orc {
     symbol: String,
     color: Color,
     experience_gain: usize,
+    ticks_between_steps: u128,
 }
 
 impl Orc {
@@ -74,6 +78,7 @@ impl Orc {
             symbol: String::from("O"),
             color: Color::DarkGray,
             experience_gain: 10,
+            ticks_between_steps: 10,
         }
     }
 }