fix: always use tracing, provide timing info 2s in + every 60s first

.gitignore

@@ -1,2 +1,4 @@
 /target
-.idea
+/dist
+.idea
+*.dll

Cargo.lock

@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43f6cb1bf222025340178f382c426f13757b2960e89779dfcb319c32542a5a41"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -26,14 +35,129 @@ version = "0.2.147"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4668fb0ea861c1df094127ac5f1da3409a82116a4ba74fca2e58ef927159bb3"
 
+[[package]]
+name = "log"
+version = "0.4.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5e6163cb8c49088c2c36f57875e58ccd8c87c7427f7fbd50ea6710b2f3f2e8f"
+
+[[package]]
+name = "matchers"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8263075bb86c5a1b1427b5ae862e8889656f126e9f77c484496e8b47cf5c5558"
+dependencies = [
+ "regex-automata 0.1.10",
+]
+
+[[package]]
+name = "memchr"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
+
+[[package]]
+name = "nu-ansi-term"
+version = "0.46.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77a8165726e8236064dbb45459242600304b42a5ea24ee2948e18e023bf7ba84"
+dependencies = [
+ "overload",
+ "winapi",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
+
+[[package]]
+name = "overload"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
+
 [[package]]
 name = "pacman"
 version = "0.1.0"
 dependencies = [
  "lazy_static",
  "sdl2",
+ "spin_sleep",
+ "tracing",
+ "tracing-error",
+ "tracing-subscriber",
 ]
 
+[[package]]
+name = "pin-project-lite"
+version = "0.2.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8afb450f006bf6385ca15ef45d71d2288452bc3683ce2e2cacc0d18e4be60b58"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.66"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18fb31db3f9bddb2ea821cde30a9f70117e3f119938b5ee630b7403aa6e2ead9"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "regex"
+version = "1.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2eae68fc220f7cf2532e4494aded17545fce192d59cd996e0fe7887f4ceb575"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata 0.3.3",
+ "regex-syntax 0.7.4",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c230d73fb8d8c1b9c0b3135c5142a8acee3a0558fb8db5cf1cb65f8d7862132"
+dependencies = [
+ "regex-syntax 0.6.29",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39354c10dd07468c2e73926b23bb9c2caca74c5501e38a35da70406f1d923310"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax 0.7.4",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
+
+[[package]]
+name = "regex-syntax"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5ea92a5b6195c6ef2a0295ea818b312502c6fc94dde986c5553242e18fd4ce2"
+
 [[package]]
 name = "sdl2"
 version = "0.35.2"
@@ -57,8 +181,160 @@ dependencies = [
  "version-compare",
 ]
 
+[[package]]
+name = "sharded-slab"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "900fba806f70c630b0a382d0d825e17a0f19fcd059a2ade1ff237bcddf446b31"
+dependencies = [
+ "lazy_static",
+]
+
+[[package]]
+name = "smallvec"
+version = "1.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62bb4feee49fdd9f707ef802e22365a35de4b7b299de4763d44bfea899442ff9"
+
+[[package]]
+name = "spin_sleep"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cafa7900db085f4354dbc7025e25d7a839a14360ea13b5fc4fd717f2d3b23134"
+dependencies = [
+ "once_cell",
+ "winapi",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "718fa2415bcb8d8bd775917a1bf12a7931b6dfa890753378538118181e0cb398"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "thread_local"
+version = "1.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3fdd6f064ccff2d6567adcb3873ca630700f00b5ad3f060c25b5dcfd9a4ce152"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+]
+
+[[package]]
+name = "tracing"
+version = "0.1.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ce8c33a8d48bd45d624a6e523445fd21ec13d3653cd51f681abf67418f54eb8"
+dependencies = [
+ "cfg-if",
+ "pin-project-lite",
+ "tracing-attributes",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-attributes"
+version = "0.1.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f4f31f56159e98206da9efd823404b79b6ef3143b4a7ab76e67b1751b25a4ab"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "tracing-core"
+version = "0.1.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0955b8137a1df6f1a2e9a37d8a6656291ff0297c1a97c24e0d8425fe2312f79a"
+dependencies = [
+ "once_cell",
+ "valuable",
+]
+
+[[package]]
+name = "tracing-error"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d686ec1c0f384b1277f097b2f279a2ecc11afe8c133c1aabf036a27cb4cd206e"
+dependencies = [
+ "tracing",
+ "tracing-subscriber",
+]
+
+[[package]]
+name = "tracing-log"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ddad33d2d10b1ed7eb9d1f518a5674713876e97e5bb9b7345a7984fbb4f922"
+dependencies = [
+ "lazy_static",
+ "log",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-subscriber"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30a651bc37f915e81f087d86e62a18eec5f79550c7faff886f7090b4ea757c77"
+dependencies = [
+ "matchers",
+ "nu-ansi-term",
+ "once_cell",
+ "regex",
+ "sharded-slab",
+ "smallvec",
+ "thread_local",
+ "tracing",
+ "tracing-core",
+ "tracing-log",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "301abaae475aa91687eb82514b328ab47a211a533026cb25fc3e519b86adfc3c"
+
+[[package]]
+name = "valuable"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "830b7e5d4d90034032940e4ace0d9a9a057e7a45cd94e6c007832e39edb82f6d"
+
 [[package]]
 name = "version-compare"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "579a42fc0b8e0c63b76519a339be31bed574929511fa53c1a3acae26eb258f29"
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

Cargo.toml

@@ -8,3 +8,7 @@ edition = "2021"
 [dependencies]
 lazy_static = "1.4.0"
 sdl2 = { version = "0.35", features = ["image", "ttf", "mixer"] }
+spin_sleep = "1.1.1"
+tracing = { version = "0.1.37", features = ["max_level_debug", "release_max_level_warn"]}
+tracing-error = "0.2.0"
+tracing-subscriber = {version = "0.3.17", features = ["env-filter"]}

README.md

@@ -49,6 +49,16 @@ The latest releases can be found here:
 
 Download each for your architecture, and locate the appropriately named DLL within. Move said DLL to root of this project.
 
+In total, you should have the following DLLs in the root of the project:
+
+- SDL2.dll
+- SDL2_mixer.dll
+- SDL2_ttf.dll
+- SDL2_image.dll
+- libpngX-X.dll
+    - Not sure on what specific version is to be used, or if naming matters. `libpng16-16.dll` is what I had used.
+- zlib1.dll
+
 ## Building
 
 To build the project, run the following command:

src/animation.rs

@@ -38,11 +38,13 @@ impl<'a> AnimatedTexture<'a> {
         }
     }
 
+    // Get the current frame number
     fn current_frame(&self) -> u32 {
         self.ticker / self.ticks_per_frame
     }
 
-    fn next_frame(&mut self) {
+    // Move to the next frame. If we are at the end of the animation, reverse the direction
+    pub fn tick(&mut self) {
         if self.reversed {
             self.ticker -= 1;
 
@@ -58,9 +60,14 @@ impl<'a> AnimatedTexture<'a> {
         }
     }
 
-    fn get_frame_rect(&self) -> Rect {
+    // Calculate the frame rect (portion of the texture to render) for the given frame.
+    fn get_frame_rect(&self, frame: u32) -> Rect {
+        if frame >= self.frame_count {
+            panic!("Frame {} is out of bounds for this texture", frame);
+        }
+
         Rect::new(
-            self.current_frame() as i32 * self.frame_width as i32,
+            frame as i32 * self.frame_width as i32,
             0,
             self.frame_width,
             self.frame_height,
@@ -73,7 +80,18 @@ impl<'a> AnimatedTexture<'a> {
         position: (i32, i32),
         direction: Direction,
     ) {
-        let frame_rect = self.get_frame_rect();
+        self.render_static(canvas, position, direction, Some(self.current_frame()));
+        self.tick();
+    }
+    
+    pub fn render_static(
+        &mut self,
+        canvas: &mut Canvas<Window>,
+        position: (i32, i32),
+        direction: Direction,
+        frame: Option<u32>,
+    ) {
+        let frame_rect = self.get_frame_rect(frame.unwrap_or(self.current_frame()));
         let position_rect = Rect::new(
             position.0 + self.offset.0,
             position.1 + self.offset.1,
@@ -92,7 +110,5 @@ impl<'a> AnimatedTexture<'a> {
                 false,
             )
             .expect("Could not render texture on canvas");
-
-        self.next_frame();
     }
 }

src/direction.rs

@@ -1,3 +1,5 @@
+use sdl2::keyboard::Keycode;
+
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub enum Direction {
     Up,
@@ -15,4 +17,27 @@ impl Direction {
             Direction::Up => 270f64,
         }
     }
+
+    pub fn offset(&self) -> (i32, i32) {
+        match self {
+            Direction::Right => (1, 0),
+            Direction::Down => (0, 1),
+            Direction::Left => (-1, 0),
+            Direction::Up => (0, -1),
+        }
+    }
+
+    pub fn from_keycode(keycode: Keycode) -> Option<Direction> {
+        match keycode {
+            Keycode::D => Some(Direction::Right),
+            Keycode::Right => Some(Direction::Right),
+            Keycode::A => Some(Direction::Left),
+            Keycode::Left => Some(Direction::Left),
+            Keycode::W => Some(Direction::Up),
+            Keycode::Up => Some(Direction::Up),
+            Keycode::S => Some(Direction::Down),
+            Keycode::Down => Some(Direction::Down),
+            _ => None,
+        }
+    }
 }

src/game.rs

@@ -1,13 +1,13 @@
 use sdl2::image::LoadTexture;
 use sdl2::keyboard::Keycode;
-use sdl2::render::{TextureCreator, Texture};
+use sdl2::render::{Texture, TextureCreator};
 use sdl2::video::WindowContext;
 use sdl2::{pixels::Color, render::Canvas, video::Window};
 
 use crate::constants::{MapTile, BOARD, BOARD_HEIGHT, BOARD_WIDTH};
 use crate::direction::Direction;
 use crate::entity::Entity;
-use crate::pacman::{Pacman};
+use crate::pacman::Pacman;
 
 pub struct Game<'a> {
     canvas: &'a mut Canvas<Window>,
@@ -24,7 +24,7 @@ impl Game<'_> {
         let pacman_atlas = texture_creator
             .load_texture("assets/32/pacman.png")
             .expect("Could not load pacman texture");
-        let pacman = Pacman::new(None, pacman_atlas);
+        let pacman = Pacman::new(Some(Game::cell_to_pixel((1, 4))), pacman_atlas);
 
         Game {
             canvas,
@@ -36,6 +36,10 @@ impl Game<'_> {
         }
     }
 
+    pub fn cell_to_pixel(cell: (u32, u32)) -> (i32, i32) {
+        ((cell.0 as i32 * 24), ((cell.1) as i32 * 24))
+    }
+
     pub fn keyboard_event(&mut self, keycode: Keycode) {
         match keycode {
             Keycode::D => {
@@ -65,7 +69,7 @@ impl Game<'_> {
         // Clear the screen (black)
         self.canvas.set_draw_color(Color::RGB(0, 0, 0));
         self.canvas.clear();
-        
+
         self.canvas
             .copy(&self.map_texture, None, None)
             .expect("Could not render texture on canvas");
@@ -75,25 +79,46 @@ impl Game<'_> {
 
         // Draw a grid
         if self.debug {
-        for x in 0..BOARD_WIDTH {
-            for y in 0..BOARD_HEIGHT {
-                let tile = BOARD[x as usize][y as usize];
-                let color = match tile {
-                    MapTile::Empty => None,
-                    MapTile::Wall => Some(Color::BLUE),
-                    MapTile::Pellet => Some(Color::RED),
-                    MapTile::PowerPellet => Some(Color::MAGENTA),
-                    MapTile::StartingPosition(_) => Some(Color::GREEN),
-                };
+            for x in 0..BOARD_WIDTH {
+                for y in 0..BOARD_HEIGHT {
+                    let tile = BOARD[x as usize][y as usize];
+                    let mut color = None;
 
-                if let Some(color) = color {
-                    self.canvas.set_draw_color(color);
-                    self.canvas
-                        .draw_rect(sdl2::rect::Rect::new(x as i32 * 24, y as i32 * 24, 24, 24))
-                        .expect("Could not draw rectangle");
+                    if (x, y) == self.pacman.cell_position() {
+                        self.draw_cell((x, y), Color::CYAN);
+                    } else {
+                        color = match tile {
+                            MapTile::Empty => None,
+                            MapTile::Wall => Some(Color::BLUE),
+                            MapTile::Pellet => Some(Color::RED),
+                            MapTile::PowerPellet => Some(Color::MAGENTA),
+                            MapTile::StartingPosition(_) => Some(Color::GREEN),
+                        };
+                    }
+
+                    if let Some(color) = color {
+                        self.draw_cell((x, y), color);
+                    }
                 }
             }
+
+            // Draw the next cell
+            let next_cell = self.pacman.next_cell(None);
+            self.draw_cell((next_cell.0 as u32, next_cell.1 as u32), Color::YELLOW);
         }
-        }
+
+        self.canvas.present();
+    }
+
+    fn draw_cell(&mut self, cell: (u32, u32), color: Color) {
+        self.canvas.set_draw_color(color);
+        self.canvas
+            .draw_rect(sdl2::rect::Rect::new(
+                cell.0 as i32 * 24,
+                cell.1 as i32 * 24,
+                24,
+                24,
+            ))
+            .expect("Could not draw rectangle");
     }
 }

src/helper.rs

@@ -0,0 +1,15 @@
+pub fn is_adjacent(a: (u32, u32), b: (u32, u32), diagonal: bool) -> bool {
+    let (ax, ay) = a;
+    let (bx, by) = b;
+    if diagonal {
+        (ax == bx && (ay == by + 1 || ay == by - 1))
+            || (ay == by && (ax == bx + 1 || ax == bx - 1))
+            || (ax == bx + 1 && ay == by + 1)
+            || (ax == bx + 1 && ay == by - 1)
+            || (ax == bx - 1 && ay == by + 1)
+            || (ax == bx - 1 && ay == by - 1)
+    } else {
+        (ax == bx && (ay == by + 1 || ay == by - 1))
+            || (ay == by && (ax == bx + 1 || ax == bx - 1))
+    }
+}

src/main.rs

@@ -1,25 +1,40 @@
 use crate::constants::{WINDOW_HEIGHT, WINDOW_WIDTH};
 use crate::game::Game;
+use tracing::{event};
 use sdl2::event::{Event};
 use sdl2::keyboard::Keycode;
-use sdl2::pixels::Color;
-use sdl2::render::{Canvas, Texture};
 use std::time::{Duration, Instant};
+use spin_sleep::sleep;
+use tracing_error::ErrorLayer;
+use tracing_subscriber::layer::SubscriberExt;
 
 #[cfg(target_os = "emscripten")]
 pub mod emscripten;
 
+mod animation;
 mod constants;
 mod direction;
+mod entity;
 mod game;
 mod pacman;
-mod entity;
-mod animation;
+mod modulation;
+mod map;
+
+#[cfg(target_os = "emscripten")]
+mod emscripten;
 
 pub fn main() {
     let sdl_context = sdl2::init().unwrap();
     let video_subsystem = sdl_context.video().unwrap();
 
+    // Setup tracing
+    let subscriber = tracing_subscriber::fmt()
+        .with_max_level(tracing::Level::DEBUG)
+        .finish()
+        .with(ErrorLayer::default());
+
+    tracing::subscriber::set_global_default(subscriber).expect("Could not set global default");
+
     let window = video_subsystem
         .window("Pac-Man", WINDOW_WIDTH, WINDOW_HEIGHT)
         .position_centered()
@@ -43,11 +58,18 @@ pub fn main() {
         .event_pump()
         .expect("Could not get SDL EventPump");
 
+    // Initial draw and tick
     game.draw();
     game.tick();
 
-    let loop_time = Duration::from_millis(1000 / 60);
+    let loop_time = Duration::from_secs(1) / 60;
+    let mut tick_no = 0u32;
 
+    // The start of a period of time over which we average the frame time.
+    let mut last_averaging_time = Instant::now();
+    let mut sleep_time = Duration::ZERO;
+
+    event!(tracing::Level::INFO, "Starting game loop ({:.3}ms)", loop_time.as_secs_f32() * 1000.0);
     let mut main_loop = || {
         let start = Instant::now();
 
@@ -58,10 +80,13 @@ pub fn main() {
                 | Event::KeyDown {
                     keycode: Some(Keycode::Escape) | Some(Keycode::Q),
                     ..
-                } => return false,
-                Event::KeyDown { keycode , .. } => {
-                    game.keyboard_event(keycode.unwrap());
+                } => {
+                    event!(tracing::Level::INFO, "Exit requested. Exiting...");
+                    return false
                 },
+                Event::KeyDown { keycode, .. } => {
+                    game.keyboard_event(keycode.unwrap());
+                }
                 _ => {}
             }
         }
@@ -70,9 +95,34 @@ pub fn main() {
         game.draw();
 
         if start.elapsed() < loop_time {
-            ::std::thread::sleep(loop_time - start.elapsed());
+            let time = loop_time - start.elapsed();
+            sleep(time);
+            sleep_time += time;
         } else {
-            println!("Game loop behind schedule by: {:?}", start.elapsed() - loop_time);
+            event!(
+                tracing::Level::WARN,
+                "Game loop behind schedule by: {:?}",
+                start.elapsed() - loop_time
+            );
+        }
+
+        tick_no += 1;
+
+        if tick_no % (60 * 60) == 0 || tick_no == (60 * 2) {
+            let average_fps = (tick_no % (60 * 60)) as f32 / last_averaging_time.elapsed().as_secs_f32();
+            let average_sleep = sleep_time / tick_no;
+            let average_process = loop_time - average_sleep;
+
+            event!(
+                tracing::Level::DEBUG,
+                "Timing Averages [fps={}] [sleep={:?}] [process={:?}]",
+                average_fps,
+                average_sleep,
+                average_process    
+            );
+
+            sleep_time = Duration::ZERO;
+            last_averaging_time = Instant::now();
         }
 
         true

src/modulation.rs

@@ -0,0 +1,48 @@
+/// A tick modulator allows you to slow down operations by a percentage.
+/// 
+/// Unfortunately, switching to floating point numbers for entities can induce floating point errors, slow down calculations
+/// and make the game less deterministic. This is why we use a speed modulator instead.
+/// Additionally, with small integers, lowering the speed by a percentage is not possible. For example, if we have a speed of 2,
+/// and we want to slow it down by 10%, we would need to slow it down by 0.2. However, since we are using integers, we can't.
+/// The only amount you can slow it down by is 1, which is 50% of the speed.
+/// 
+/// The basic principle of the Speed Modulator is to instead 'skip' movement ticks every now and then.
+/// At 60 ticks per second, skips could happen several times per second, or once every few seconds.
+/// Whatever it be, as long as the tick rate is high enough, the human eye will not be able to tell the difference.
+/// 
+/// For example, if we want to slow down the speed by 10%, we would need to skip every 10th tick.
+pub trait TickModulator {
+    fn new(percent: f32) -> Self;
+    fn next(&mut self) -> bool;
+}
+
+pub struct SimpleTickModulator {
+    tick_count: u32,
+    ticks_left: u32,
+}
+
+// TODO: Add tests
+// TODO: Look into average precision, binary code modulation strategy
+impl TickModulator for SimpleTickModulator {
+    fn new(percent: f32) -> Self {
+        let ticks_required: u32 = (1f32 / (1f32 - percent)).round() as u32;
+
+        SimpleTickModulator {
+            tick_count: ticks_required,
+            ticks_left: ticks_required,
+        }
+    }
+
+    fn next(&mut self) -> bool {
+        self.ticks_left -= 1;
+
+        // Return whether or not we should skip this tick
+        if self.ticks_left == 0 {
+            // We've reached the tick to skip, reset the counter
+            self.ticks_left = self.tick_count;
+            false
+        } else {
+            true
+        }
+    }
+}

src/pacman.rs

@@ -3,14 +3,20 @@ use sdl2::{
     video::Window,
 };
 
-use crate::{animation::AnimatedTexture, direction::Direction, entity::Entity, constants::CELL_SIZE};
+use crate::{
+    constants::{BOARD, MapTile},
+    animation::AnimatedTexture, constants::CELL_SIZE, direction::Direction, entity::Entity,
+    modulation::SpeedModulator,
+};
 
 pub struct Pacman<'a> {
     // Absolute position on the board (precise)
     pub position: (i32, i32),
     pub direction: Direction,
     pub next_direction: Option<Direction>,
+    pub stopped: bool,
     speed: u32,
+    modulation: SpeedModulator,
     sprite: AnimatedTexture<'a>,
 }
 
@@ -21,6 +27,8 @@ impl Pacman<'_> {
             direction: Direction::Right,
             next_direction: None,
             speed: 2,
+            stopped: false,
+            modulation: SpeedModulator::new(0.9333),
             sprite: AnimatedTexture::new(atlas, 4, 3, 32, 32, Some((-4, -4))),
         }
     }
@@ -28,6 +36,12 @@ impl Pacman<'_> {
     pub fn render(&mut self, canvas: &mut Canvas<Window>) {
         self.sprite.render(canvas, self.position, self.direction);
     }
+
+    fn next_cell(&self) -> (i32, i32) {
+        let (x, y) = self.direction.offset();
+        let cell = self.cell_position();
+        (cell.0 as i32 + x, cell.1 as i32 + y)
+    }
 }
 
 impl Entity for Pacman<'_> {
@@ -53,28 +67,34 @@ impl Entity for Pacman<'_> {
 
     fn tick(&mut self) {
         let can_change = self.internal_position() == (0, 0);
-        println!("{:?} ({:?})", self.internal_position(), can_change);
         if can_change {
             if let Some(direction) = self.next_direction {
                 self.direction = direction;
                 self.next_direction = None;
             }
         }
-        
-        let speed = self.speed as i32;
-        match self.direction {
-            Direction::Right => {
-                self.position.0 += speed;
-            }
-            Direction::Left => {
-                self.position.0 -= speed;
-            }
-            Direction::Up => {
-                self.position.1 -= speed;
-            }
-            Direction::Down => {
-                self.position.1 += speed;
+
+        if !self.stopped && self.modulation.next() {
+            let speed = self.speed as i32;
+            match self.direction {
+                Direction::Right => {
+                    self.position.0 += speed;
+                }
+                Direction::Left => {
+                    self.position.0 -= speed;
+                }
+                Direction::Up => {
+                    self.position.1 -= speed;
+                }
+                Direction::Down => {
+                    self.position.1 += speed;
+                }
             }
         }
+
+        let next = self.next_cell();
+        if BOARD[next.1 as usize][next.0 as usize] == MapTile::Wall {
+            self.stopped = true;
+        }
     }
 }