improved canvas display and added controls

src/main.rs

@@ -17,12 +17,14 @@ fn deserialize(str: &str) -> Vec<Pos> {
     let mut pos = pos!(0, 0);
     for c in str.chars() {
         match c {
-            '#' => {
+            ' ' => {
+                pos.x += 1;
+            }
+            '\n' => pos = pos!(0, pos.y + 1),
+            _ => {
                 result.push(pos);
                 pos.x += 1
             }
-            '\n' => pos = pos!(0, pos.y + 1),
-            _ => pos.x += 1,
         }
     }
     result

src/sim.rs

@@ -33,24 +33,22 @@ where
     fn possible_change_pos(&self) -> impl Iterator<Item = Pos> + '_ {
         self.actives()
             .into_iter()
-            .map(|p| self.get_neighbors(p))
-            .flatten()
+            .flat_map(|p| self.get_neighbors(p))
     }
 
     pub fn get_neighbors(&self, pos: Pos) -> impl Iterator<Item = Pos> + '_ {
         (-1..=1)
-            .map(|x| (-1..=1).map(move |y| pos!(x, y)))
-            .flatten()
+            .flat_map(|x| (-1..=1).map(move |y| pos!(x, y)))
             .map(move |p| pos + p)
     }
 
     pub fn is_cell_alive(&self, pos: Pos) -> bool {
-        self.get(pos.clone()).is_active()
+        self.get(pos).is_active()
     }
 
     pub fn get_neighbor_count(&self, pos: Pos) -> usize {
         self.get_neighbors(pos)
-            .filter(|pos| self.is_cell_alive(pos.clone()))
+            .filter(|pos| self.is_cell_alive(*pos))
             .count()
     }
 
@@ -64,6 +62,8 @@ where
     W: World,
 {
     Snapshot(mpsc::Sender<W>),
+    SetDelay(u64),
+    Delay(mpsc::Sender<usize>),
 }
 
 pub struct SimHandle<W>
@@ -86,6 +86,16 @@ where
         self.sender.send(SimCmd::Snapshot(sender)).unwrap();
         receiver.recv().unwrap()
     }
+
+    pub fn delay(&self) -> usize {
+        let (sender, receiver) = mpsc::channel();
+        self.sender.send(SimCmd::Delay(sender)).unwrap();
+        receiver.recv().unwrap()
+    }
+
+    pub fn set_delay(&self, delay_ms: u64) {
+        self.sender.send(SimCmd::SetDelay(delay_ms)).unwrap();
+    }
 }
 
 #[derive(Debug)]
@@ -124,23 +134,25 @@ where
 }
 
 const EVT_CHECK_TIMEOUT: Duration = Duration::from_millis(10);
-const SIM_TICK_INTERVAL: Duration = Duration::from_millis(200);
 
 fn sim_loop<W>(receiver: mpsc::Receiver<SimCmd<W>>, state: State<W>)
 where
     W: World,
 {
+    let mut tick_interval = Duration::from_millis(200);
     let mut current_state = state;
     let mut last_update = SystemTime::now();
 
     loop {
-        if let Some(cmd) = receiver.try_recv().ok() {
+        if let Ok(cmd) = receiver.try_recv() {
             match cmd {
                 SimCmd::Snapshot(sender) => sender.send(current_state.snapshot()).unwrap(),
+                SimCmd::SetDelay(delay) => tick_interval = Duration::from_millis(delay),
+                SimCmd::Delay(sender) => sender.send(tick_interval.as_millis() as usize).unwrap(),
             }
         }
 
-        if SystemTime::now().duration_since(last_update).unwrap() > SIM_TICK_INTERVAL {
+        if SystemTime::now().duration_since(last_update).unwrap() > tick_interval {
             let old_state = current_state;
             let mut new_state: State<W> = State::default();
 
@@ -148,7 +160,7 @@ where
                 let is_active = old_state.is_cell_alive(pos);
                 let neighbor_count = old_state.get_neighbor_count(pos);
                 match (is_active, neighbor_count) {
-                    (true, count) if count < 3 || count > 4 => (),   // die
+                    (true, count) if !(3..=4).contains(&count) => (), // die
                     (true, _) => new_state.set(pos, Cell::active()),  // stay
                     (false, 3) => new_state.set(pos, Cell::active()), // becomes alive
                     _ => (),                                          // stays dead

src/utils.rs

@@ -9,7 +9,7 @@ pub struct Pos {
 #[macro_export]
 macro_rules! pos {
     ($x:expr, $y:expr) => {
-        crate::Pos { x: $x, y: $y }
+        Pos { x: $x, y: $y }
     };
 }
 

src/view.rs

@@ -1,11 +1,14 @@
 use std::{
-    io::{stdin, stdout, Write},
+    io::{stdin, stdout},
     process::exit,
     sync::mpsc,
     thread::{self, JoinHandle},
     time::Duration,
 };
 
+pub use canvas::Canvas;
+mod canvas;
+
 use termion::{event::Key, input::TermRead, raw::IntoRawMode};
 
 use crate::{pos, Pos, SimHandle, World};
@@ -52,6 +55,8 @@ fn input_loop(sender: mpsc::Sender<InputCmd>) {
             Key::Down => InputCmd::Move(Dir::Down),
             Key::Left => InputCmd::Move(Dir::Left),
             Key::Right => InputCmd::Move(Dir::Right),
+            Key::Char('+') => InputCmd::Accelerate,
+            Key::Char('-') => InputCmd::Decelerate,
             _ => continue,
         };
 
@@ -62,6 +67,7 @@ fn input_loop(sender: mpsc::Sender<InputCmd>) {
 
 const VIEW_REFRESH_INTERVAL: Duration = Duration::from_millis(100);
 
+#[allow(unreachable_code)]
 fn view_loop<W>(handle: SimHandle<W>)
 where
     W: World,
@@ -69,52 +75,89 @@ where
     let (sender, receiver) = mpsc::channel();
     let _input_handle = thread::spawn(|| input_loop(sender));
 
-    let mut view_origin = pos!(0, 0);
+    let (x, y) = termion::terminal_size().unwrap();
+    let mut delay = 200u64;
+    let mut view_origin = pos!(-(x as i32) / 2, -(y as i32));
     loop {
-        handle_inputs(&receiver, &mut view_origin);
-        let world = handle.snapshot();
-        display_world(view_origin, world);
-        thread::sleep(VIEW_REFRESH_INTERVAL);
+        handle_inputs(&receiver, &mut view_origin, &mut delay);
+        handle.set_delay(delay);
+
+        let mut canvas = Canvas::from_screen();
+        grid_layer(&mut canvas, view_origin);
+        world_layer(&mut canvas, handle.snapshot(), view_origin);
+        title_layer(&mut canvas, handle.delay());
+        canvas.display();
     }
     drop(handle);
 }
 
-fn handle_inputs(receiver: &mpsc::Receiver<InputCmd>, view_origin: &mut Pos) {
-    if let Some(cmd) = receiver.try_recv().ok() {
+const MOVEMENT_STEP: i32 = 3;
+
+fn handle_inputs(receiver: &mpsc::Receiver<InputCmd>, view_origin: &mut Pos, delay: &mut u64) {
+    if let Ok(cmd) = receiver.recv_timeout(VIEW_REFRESH_INTERVAL) {
         match cmd {
-            InputCmd::Exit => exit(0),
+            InputCmd::Exit => {
+                println!("{}{}", termion::clear::All, termion::cursor::Goto(1, 1));
+                exit(0);
+            }
             InputCmd::Move(direction) => {
                 *view_origin = *view_origin
                     + match direction {
-                        Dir::Up => pos!(0, -4),
-                        Dir::Down => pos!(0, 4),
-                        Dir::Left => pos!(-4, 0),
-                        Dir::Right => pos!(4, 0),
+                        Dir::Up => pos!(0, -MOVEMENT_STEP),
+                        Dir::Down => pos!(0, MOVEMENT_STEP),
+                        Dir::Left => pos!(-2 * MOVEMENT_STEP, 0),
+                        Dir::Right => pos!(2 * MOVEMENT_STEP, 0),
                     }
             }
-            InputCmd::Accelerate => todo!(),
-            InputCmd::Decelerate => todo!(),
+            InputCmd::Accelerate => *delay -= 100,
+            InputCmd::Decelerate => *delay += 100,
         }
     }
 }
 
-fn display_world<W>(view_origin: Pos, world: W)
+fn grid_layer(canvas: &mut Canvas, view_origin: Pos) {
+    canvas.layer(|local_pos| {
+        let Pos { x, y } = local_pos + view_origin;
+        match (x % 16 == 0, y % 8 == 0) {
+            (true, true) => Some('┼'),
+            (true, _) => Some('│'),
+            (_, true) => Some('─'),
+            _ => None,
+        }
+    })
+}
+
+fn world_layer<W>(canvas: &mut Canvas, world: W, view_origin: Pos)
 where
     W: World,
 {
-    let (width, height) = termion::terminal_size().unwrap();
-    let mut result = String::new();
+    canvas.layer(|mut local_pos| {
+        local_pos.y *= 2;
+        let pos_top = local_pos + view_origin;
+        let top = world.get(pos_top).is_active();
+        let pos_bottom = pos_top + pos!(0, 1);
+        let bottom = world.get(pos_bottom).is_active();
 
-    for ly in 0..(height) {
-        let next_line = termion::cursor::Goto(1, ly + 1);
-        result += &format!("{next_line}");
-        for lx in 0..width {
-            let pos = view_origin + pos!(lx as i32, ly as i32);
-            let char = &if world.get(pos).is_active() { "#" } else { " " };
-            result += char
+        match (top, bottom) {
+            (true, true) => Some('█'),
+            (true, _) => Some('▀'),
+            (_, true) => Some('▄'),
+            _ => None,
         }
+    });
 }
-    let clear = termion::clear::All;
-    print!("{clear}{result}");
-    stdout().flush().unwrap();
+
+#[allow(clippy::useless_format)]
+fn title_layer(canvas: &mut Canvas, de: usize) {
+    let table = [
+        format!("│   <golrs>   | [+]: speed up  │"),
+        format!("│ delay:      | [-]: slow down │"),
+        format!("│  {de:>7} ms | [q]: quit      │"),
+        format!("└──────────────────────────────┘"),
+    ];
+    canvas.layer(|Pos { x, y }| {
+        table
+            .get(y as usize)
+            .and_then(|line| line.chars().nth(x as usize))
+    })
 }

src/view/canvas.rs

@@ -0,0 +1,54 @@
+use std::io::{stdout, Write};
+
+use crate::{pos, Pos};
+
+pub struct Canvas {
+    lines: Vec<String>,
+    width: usize,
+    height: usize,
+}
+
+impl Canvas {
+    pub fn from_screen() -> Self {
+        let (width, height) = termion::terminal_size().unwrap();
+        Self::new(width as usize, (height - 1) as usize)
+    }
+
+    pub fn new(width: usize, height: usize) -> Self {
+        let lines = (0..height)
+            .map(|_| (0..width).map(|_| ' '.to_string()).collect::<String>())
+            .collect();
+        Self {
+            height,
+            lines,
+            width,
+        }
+    }
+
+    pub fn layer(&mut self, f: impl Fn(Pos) -> Option<char>) {
+        for y in 0..self.height {
+            for x in 0..self.width {
+                if let Some(char) = f(pos!(x as i32, y as i32)) {
+                    let line = &mut self.lines[y];
+                    line.replace_range(
+                        line.char_indices()
+                            .nth(x)
+                            .map(|(pos, ch)| (pos..pos + ch.len_utf8()))
+                            .unwrap(),
+                        &format!("{char}"),
+                    );
+                }
+            }
+        }
+    }
+
+    pub fn display(&self) {
+        let clear = termion::clear::All;
+        print!("{clear}");
+        for (index, line) in self.lines.iter().enumerate() {
+            let goto = termion::cursor::Goto(1, index as u16 + 1);
+            println!("{goto}{line}");
+        }
+        stdout().flush().unwrap();
+    }
+}

src/world.rs

@@ -1,6 +1,6 @@
 use crate::Pos;
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Default, Clone, PartialEq, Eq)]
 pub struct Cell {
     active: bool,
 }
@@ -19,12 +19,6 @@ impl Cell {
     }
 }
 
-impl Default for Cell {
-    fn default() -> Self {
-        Cell { active: false }
-    }
-}
-
 pub trait World: Default + Clone + Send + 'static {
     fn get(&self, pos: Pos) -> Cell;
     fn set(&mut self, pos: Pos, cell: Cell);