docs: document many major functions, types, enums for important functionality

src/texture/animated.rs

@@ -1,11 +1,19 @@
 use crate::error::{AnimatedTextureError, GameError, GameResult, TextureError};
 use crate::texture::sprite::AtlasTile;
 
+/// Frame-based animation system for cycling through multiple sprite tiles.
+///
+/// Manages automatic frame progression based on elapsed time.
+/// Uses a time banking system to ensure consistent animation speed regardless of frame rate variations.
 #[derive(Debug, Clone)]
 pub struct AnimatedTexture {
+    /// Sequence of sprite tiles that make up the animation frames
     tiles: Vec<AtlasTile>,
+    /// Duration each frame should be displayed (in seconds)
     frame_duration: f32,
+    /// Index of the currently active frame in the tiles vector
     current_frame: usize,
+    /// Accumulated time since the last frame change (for smooth timing)
     time_bank: f32,
 }
 
@@ -25,6 +33,16 @@ impl AnimatedTexture {
         })
     }
 
+    /// Advances the animation by the specified time delta with automatic frame cycling.
+    ///
+    /// Accumulates time in the time bank and progresses through frames when enough
+    /// time has elapsed. Supports frame rates independent of game frame rate by
+    /// potentially advancing multiple frames in a single call if `dt` is large.
+    /// Animation loops automatically when reaching the final frame.
+    ///
+    /// # Arguments
+    ///
+    /// * `dt` - Time elapsed since the last tick (typically frame delta time)
     pub fn tick(&mut self, dt: f32) {
         self.time_bank += dt;
         while self.time_bank >= self.frame_duration {