feat: wall collisions

src/direction.rs

@@ -15,4 +15,13 @@ 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),
+        }
+    }
 }

src/entity.rs

@@ -5,6 +5,7 @@ pub trait Entity {
     fn position(&self) -> (i32, i32);
     // Returns the cell position of the entity (XY position within the grid)
     fn cell_position(&self) -> (u32, u32);
+    fn internal_position(&self) -> (u32, u32);
     // Tick the entity (move it, perform collision checks, etc) 
     fn tick(&mut self);
 }

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,
@@ -36,19 +36,23 @@ 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 => {
-                self.pacman.direction = Direction::Right;
+                self.pacman.next_direction = Some(Direction::Right);
             }
             Keycode::A => {
-                self.pacman.direction = Direction::Left;
+                self.pacman.next_direction = Some(Direction::Left);
             }
             Keycode::W => {
-                self.pacman.direction = Direction::Up;
+                self.pacman.next_direction = Some(Direction::Up);
             }
             Keycode::S => {
-                self.pacman.direction = Direction::Down;
+                self.pacman.next_direction = Some(Direction::Down);
             }
             Keycode::Space => {
                 self.debug = !self.debug;
@@ -78,22 +82,39 @@ impl Game<'_> {
             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 {
+                    let mut color = None;
+
+                    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);
+                    }
+                }
+            }
+        }
+
+        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(x as i32 * 24, y as i32 * 24, 24, 24))
+            .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

@@ -1,20 +1,22 @@
 use crate::constants::{WINDOW_HEIGHT, WINDOW_WIDTH};
 use crate::game::Game;
-use sdl2::event::{Event};
+use sdl2::event::Event;
 use sdl2::keyboard::Keycode;
-use sdl2::pixels::Color;
-use sdl2::render::{Canvas, Texture};
 use std::time::{Duration, Instant};
 
 #[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;
+
+#[cfg(target_os = "emscripten")]
+mod emscripten;
 
 pub fn main() {
     let sdl_context = sdl2::init().unwrap();
@@ -59,9 +61,9 @@ pub fn main() {
                     keycode: Some(Keycode::Escape) | Some(Keycode::Q),
                     ..
                 } => return false,
-                Event::KeyDown { keycode , .. } => {
+                Event::KeyDown { keycode, .. } => {
                     game.keyboard_event(keycode.unwrap());
-                },
+                }
                 _ => {}
             }
         }
@@ -72,7 +74,10 @@ pub fn main() {
         if start.elapsed() < loop_time {
             ::std::thread::sleep(loop_time - start.elapsed());
         } else {
-            println!("Game loop behind schedule by: {:?}", start.elapsed() - loop_time);
+            println!(
+                "Game loop behind schedule by: {:?}",
+                start.elapsed() - loop_time
+            );
         }
 
         true

src/modulation.rs

@@ -0,0 +1,26 @@
+pub struct SpeedModulator {
+    tick_count: u32,
+    ticks_left: u32,
+}
+
+impl SpeedModulator {
+    pub fn new(percent: f32) -> Self {
+        let ticks_required: u32 = (1f32 / (1f32 - percent)).round() as u32;
+
+        SpeedModulator {
+            tick_count: ticks_required,
+            ticks_left: ticks_required,
+        }
+    }
+
+    pub fn next(&mut self) -> bool {
+        self.ticks_left -= 1;
+
+        if self.ticks_left == 0 {
+            self.ticks_left = self.tick_count;
+            false
+        } else {
+            true
+        }
+    }
+}

src/pacman.rs

@@ -3,13 +3,20 @@ use sdl2::{
     video::Window,
 };
 
-use crate::{animation::AnimatedTexture, direction::Direction, entity::Entity};
+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>,
 }
 
@@ -18,14 +25,23 @@ impl Pacman<'_> {
         Pacman {
             position: starting_position.unwrap_or((0i32, 0i32)),
             direction: Direction::Right,
+            next_direction: None,
             speed: 2,
-            sprite: AnimatedTexture::new(atlas, 4, 3, 32, 32),
+            stopped: false,
+            modulation: SpeedModulator::new(0.9333),
+            sprite: AnimatedTexture::new(atlas, 4, 3, 32, 32, Some((-4, -4))),
         }
     }
 
     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<'_> {
@@ -41,10 +57,24 @@ impl Entity for Pacman<'_> {
 
     fn cell_position(&self) -> (u32, u32) {
         let (x, y) = self.position();
-        (x as u32 / 24, y as u32 / 24)
+        (x as u32 / CELL_SIZE, y as u32 / CELL_SIZE)
+    }
+
+    fn internal_position(&self) -> (u32, u32) {
+        let (x, y) = self.position();
+        (x as u32 % CELL_SIZE, y as u32 % CELL_SIZE)
     }
 
     fn tick(&mut self) {
+        let can_change = self.internal_position() == (0, 0);
+        if can_change {
+            if let Some(direction) = self.next_direction {
+                self.direction = direction;
+                self.next_direction = None;
+            }
+        }
+
+        if !self.stopped && self.modulation.next() {
             let speed = self.speed as i32;
             match self.direction {
                 Direction::Right => {
@@ -61,4 +91,10 @@ impl Entity for Pacman<'_> {
                 }
             }
         }
+
+        let next = self.next_cell();
+        if BOARD[next.1 as usize][next.0 as usize] == MapTile::Wall {
+            self.stopped = true;
+        }
+    }
 }