Some examples of documentation (#338)

crates/bevy_ecs/hecs/src/query.rs

@@ -240,7 +240,9 @@ impl<'a, T: Component> Fetch<'a> for FetchMut<T> {
     }
 }
 
-#[allow(missing_docs)]
+/// Query transformer that skips entities that have a `T` component that has
+/// not been mutated since the last pass of the system. This does not include
+/// components that were added in since the last pass.
 pub struct Mutated<'a, T> {
     value: &'a T,
 }
@@ -368,7 +370,8 @@ impl<'a, T: Component> Fetch<'a> for FetchAdded<T> {
     }
 }
 
-#[allow(missing_docs)]
+/// Query transformer skipping entities that have not been either mutated or added
+/// since the last pass of the system
 pub struct Changed<'a, T> {
     value: &'a T,
 }

crates/bevy_sprite/src/entity.rs

@@ -63,10 +63,15 @@ impl Default for SpriteComponents {
     }
 }
 
+/// A Bundle of components for drawing a single sprite from a sprite sheet (also referred
+/// to as a `TextureAtlas`)
 #[derive(Bundle)]
 pub struct SpriteSheetComponents {
+    /// The specific sprite from the texture atlas to be drawn
     pub sprite: TextureAtlasSprite,
+    /// A handle to the texture atlas that holds the sprite images
     pub texture_atlas: Handle<TextureAtlas>,
+    /// Data pertaining to how the sprite is drawn on the screen
     pub draw: Draw,
     pub render_pipelines: RenderPipelines,
     pub main_pass: MainPass,

crates/bevy_sprite/src/texture_atlas.rs

@@ -9,11 +9,14 @@ use bevy_render::{
 };
 use std::collections::HashMap;
 
+/// An atlas containing multiple textures (like a spritesheet or a tilemap)
 #[derive(RenderResources)]
 pub struct TextureAtlas {
+    /// The handle to the texture in which the sprites are stored
     pub texture: Handle<Texture>,
     // TODO: add support to Uniforms derive to write dimensions and sprites to the same buffer
     pub size: Vec2,
+    /// The specific areas of the atlas where each texture can be found
     #[render_resources(buffer)]
     pub textures: Vec<Rect>,
     #[render_resources(ignore)]
@@ -48,6 +51,8 @@ impl TextureAtlasSprite {
 }
 
 impl TextureAtlas {
+    /// Create a new `TextureAtlas` that has a texture, but does not have
+    /// any individual sprites specified
     pub fn new_empty(texture: Handle<Texture>, dimensions: Vec2) -> Self {
         Self {
             texture,
@@ -57,6 +62,8 @@ impl TextureAtlas {
         }
     }
 
+    /// Generate a `TextureAtlas` by splitting a texture into a grid where each
+    /// cell of the grid is one of the textures in the atlas
     pub fn from_grid(
         texture: Handle<Texture>,
         size: Vec2,
@@ -85,10 +92,17 @@ impl TextureAtlas {
         }
     }
 
+    /// Add a sprite to the list of textures in the `TextureAtlas`
+    ///
+    /// # Arguments
+    ///
+    /// * `rect` - The section of the atlas that contains the texture to be added,
+    /// from the top-left corner of the texture to the bottom-right corner
     pub fn add_texture(&mut self, rect: Rect) {
         self.textures.push(rect);
     }
 
+    /// How many textures are in the `TextureAtlas`
     pub fn len(&self) -> usize {
         self.textures.len()
     }