refactor: move DIRECTIONS constant into direction, add as_u8() const fn for array indexing

src/entity/pacman.rs

@@ -1,3 +1,9 @@
+//! Pac-Man entity implementation.
+//!
+//! This module contains the main player character logic, including movement,
+//! animation, and rendering. Pac-Man moves through the game graph using
+//! a traverser and displays directional animated textures.
+
 use glam::{UVec2, Vec2};
 
 use crate::constants::BOARD_PIXEL_OFFSET;
@@ -11,21 +17,34 @@ use sdl2::keyboard::Keycode;
 use sdl2::render::{Canvas, RenderTarget};
 use std::collections::HashMap;
 
+/// Determines if Pac-Man can traverse a given edge.
+///
+/// Pac-Man can only move through edges that allow all entities.
 fn can_pacman_traverse(edge: Edge) -> bool {
     matches!(edge.permissions, EdgePermissions::All)
 }
 
+/// The main player character entity.
+///
+/// Pac-Man moves through the game world using a graph-based navigation system
+/// and displays directional animated sprites based on movement state.
 pub struct Pacman {
+    /// Handles movement through the game graph
     pub traverser: Traverser,
+    /// Manages directional animated textures for different movement states
     texture: DirectionalAnimatedTexture,
 }
 
 impl Pacman {
+    /// Creates a new Pac-Man instance at the specified starting node.
+    ///
+    /// Sets up animated textures for all four directions with moving and stopped states.
+    /// The moving animation cycles through open mouth, closed mouth, and full sprites.
     pub fn new(graph: &Graph, start_node: NodeId, atlas: &SpriteAtlas) -> Self {
         let mut textures = HashMap::new();
         let mut stopped_textures = HashMap::new();
 
-        for &direction in &[Direction::Up, Direction::Down, Direction::Left, Direction::Right] {
+        for direction in Direction::DIRECTIONS {
             let moving_prefix = match direction {
                 Direction::Up => "pacman/up",
                 Direction::Down => "pacman/down",
@@ -56,11 +75,19 @@ impl Pacman {
         }
     }
 
+    /// Updates Pac-Man's position and animation state.
+    ///
+    /// Advances movement through the graph and updates texture animation.
+    /// Movement speed is scaled by 60 FPS and a 1.125 multiplier.
     pub fn tick(&mut self, dt: f32, graph: &Graph) {
         self.traverser.advance(graph, dt * 60.0 * 1.125, &can_pacman_traverse);
         self.texture.tick(dt);
     }
 
+    /// Handles keyboard input to change Pac-Man's direction.
+    ///
+    /// Maps arrow keys to directions and queues the direction change
+    /// for the next valid intersection.
     pub fn handle_key(&mut self, keycode: Keycode) {
         let direction = match keycode {
             Keycode::Up => Some(Direction::Up),
@@ -75,6 +102,9 @@ impl Pacman {
         }
     }
 
+    /// Calculates the current pixel position in the game world.
+    ///
+    /// Interpolates between nodes when moving between them.
     fn get_pixel_pos(&self, graph: &Graph) -> Vec2 {
         match self.traverser.position {
             Position::AtNode(node_id) => graph.get_node(node_id).unwrap().position,
@@ -86,6 +116,10 @@ impl Pacman {
         }
     }
 
+    /// Renders Pac-Man to the canvas.
+    ///
+    /// Calculates screen position, determines if Pac-Man is stopped,
+    /// and renders the appropriate directional texture.
     pub fn render<T: RenderTarget>(&self, canvas: &mut Canvas<T>, atlas: &mut SpriteAtlas, graph: &Graph) {
         let pixel_pos = self.get_pixel_pos(graph).round().as_ivec2() + BOARD_PIXEL_OFFSET.as_ivec2();
         let dest = centered_with_size(pixel_pos, UVec2::new(16, 16));