Fix clippy warnings and make macro for error types

src/lib.rs

@@ -83,6 +83,14 @@
 //! }
 //! ```
 
+#![warn(clippy::pedantic)]
+#![allow(
+    clippy::similar_names,
+    clippy::needless_doctest_main,
+    clippy::module_name_repetitions,
+    clippy::missing_errors_doc
+)]
+
 pub mod physics;
 pub mod vec2;
 
@@ -100,7 +108,7 @@ use sdl2::{
     render::{Canvas, TextureCreator, TextureValueError},
     rwops::RWops,
     surface::Surface,
-    ttf::{FontError, Sdl2TtfContext},
+    ttf::{FontError, InitError, Sdl2TtfContext},
     video::{Window, WindowBuildError, WindowContext},
     EventPump, IntegerOrSdlError,
 };
@@ -125,37 +133,33 @@ macro_rules! cloned {
     }
 }
 
+macro_rules! error_from_format {
+    ($($t:ty),+) => {
+        $(
+        impl From<$t> for CatboxError {
+            fn from(e: $t) -> Self {
+                CatboxError(format!("{}", e))
+            }
+        }
+        )+
+    };
+}
+
 #[derive(Debug)]
 pub struct CatboxError(String);
 
-impl From<WindowBuildError> for CatboxError {
-    fn from(e: WindowBuildError) -> Self {
-        CatboxError(format!("{}", e))
-    }
-}
-
 impl From<String> for CatboxError {
     fn from(e: String) -> Self {
         CatboxError(e)
     }
 }
 
-impl From<IntegerOrSdlError> for CatboxError {
-    fn from(e: IntegerOrSdlError) -> Self {
-        CatboxError(format!("{}", e))
-    }
-}
-
-impl From<TextureValueError> for CatboxError {
-    fn from(e: TextureValueError) -> Self {
-        CatboxError(format!("{}", e))
-    }
-}
-
-impl From<FontError> for CatboxError {
-    fn from(e: FontError) -> Self {
-        CatboxError(format!("{}", e))
-    }
+error_from_format! {
+    WindowBuildError,
+    IntegerOrSdlError,
+    TextureValueError,
+    FontError,
+    InitError
 }
 
 pub type Result<T> = std::result::Result<T, CatboxError>;
@@ -301,6 +305,7 @@ impl Sprite {
     /// # let s = Sprite::new("duck.png", 500, 400).unwrap();
     /// let angle = s.angle();
     /// ```
+    #[must_use]
     pub fn angle(&self) -> f64 {
         self.angle
     }
@@ -312,6 +317,7 @@ impl Sprite {
     /// # let s = Sprite::new("duck.png", 500, 400).unwrap();
     /// let (x, y) = s.position().into();
     /// ```
+    #[must_use]
     pub fn position(&self) -> Vec2Int {
         self.rect.center().into()
     }
@@ -321,6 +327,7 @@ impl Sprite {
 ///
 /// Technically, this is a thin wrapper around a simple [`Vec`] of sprites,
 /// although with some convenience methods.
+#[derive(Default)]
 pub struct SpriteCollection {
     v: Vec<Sprite>,
 }
@@ -333,6 +340,7 @@ impl SpriteCollection {
     /// # use cat_box::*;
     /// let sprites = SpriteCollection::new();
     /// ```
+    #[must_use]
     pub fn new() -> Self {
         Self { v: Vec::new() }
     }
@@ -344,6 +352,7 @@ impl SpriteCollection {
     /// # use cat_box::*;
     /// let sprites = SpriteCollection::with_capacity(10);
     /// ```
+    #[must_use]
     pub fn with_capacity(cap: usize) -> Self {
         Self {
             v: Vec::with_capacity(cap),
@@ -361,7 +370,7 @@ impl SpriteCollection {
     /// # });
     /// ```
     pub fn draw(&mut self, ctx: &mut Context) -> Result<()> {
-        for s in self.v.iter_mut() {
+        for s in &mut self.v {
             s.draw(ctx)?;
         }
 
@@ -449,6 +458,7 @@ impl SpriteCollection {
     }
 
     /// Returns the length of this vector.
+    #[must_use]
     pub fn len(&self) -> usize {
         self.v.len()
     }
@@ -461,14 +471,21 @@ impl SpriteCollection {
     /// # sprites.push(s);
     /// let s = sprites.get(0);
     /// ```
+    #[must_use]
     pub fn get(&self, index: usize) -> Option<&Sprite> {
         self.v.get(index)
     }
 
     /// Return the inner Vec. Only use this method if you know what you're doing.
+    #[must_use]
     pub fn inner(&self) -> &Vec<Sprite> {
         &self.v
     }
+
+    #[must_use]
+    pub fn is_empty(&self) -> bool {
+        self.v.is_empty()
+    }
 }
 
 impl Deref for SpriteCollection {
@@ -550,6 +567,7 @@ impl Context {
 }
 
 /// Set the mode for drawing text.
+#[derive(Clone, Copy, Debug)]
 pub enum TextMode {
     /// Render the text transparently.
     Transparent { colour: (u8, u8, u8) },
@@ -686,6 +704,7 @@ impl Game {
     /// Game::new("cool game", 1000, 1000);
     /// ```
     ///
+    #[must_use]
     pub fn new(title: &str, width: u32, height: u32) -> Self {
         Self {
             title: title.to_string(),
@@ -716,7 +735,7 @@ impl Game {
             .build()?;
 
         let canvas = window.into_canvas().build()?;
-        let s = sdl2::ttf::init().unwrap();
+        let s = sdl2::ttf::init()?;
 
         let event_pump = sdl_context.event_pump()?;
 

src/main.rs

@@ -1,3 +1,5 @@
+#![warn(clippy::pedantic)]
+
 use cat_box::{draw_text, get_keyboard_state, get_mouse_state, Game, Sprite, SpriteCollection};
 use sdl2::keyboard::Scancode;
 
@@ -39,7 +41,7 @@ fn main() {
         let x_diff = m.x - start_x;
         let y_diff = m.y - start_y;
 
-        let angle = (y_diff as f64).atan2(x_diff as f64);
+        let angle = f64::from(y_diff).atan2(f64::from(x_diff));
         s.set_angle(angle.to_degrees());
 
         for spr in coll.iter() {
@@ -48,7 +50,7 @@ fn main() {
             let x_diff = m.x - start_x;
             let y_diff = m.y - start_y;
 
-            let angle = (y_diff as f64).atan2(x_diff as f64);
+            let angle = f64::from(y_diff).atan2(f64::from(x_diff));
             spr.set_angle(angle.to_degrees());
         }
 

src/physics.rs

@@ -2,6 +2,8 @@
 //!
 //! Still ***very much work-in-progress***
 
+#![allow(clippy::cast_possible_wrap)]
+
 use crate::{Sprite, SpriteCollection};
 use std::cmp::max;
 
@@ -28,16 +30,18 @@ fn collided(sprite1: &Sprite, sprite2: &Sprite) -> bool {
         return false;
     }
 
-    return sprite1.rect.has_intersection(sprite2.rect);
+    sprite1.rect.has_intersection(sprite2.rect)
 }
 
 /// Check if two sprites are touching or overlapping.
+#[must_use]
 pub fn check_for_collision(sprite1: &Sprite, sprite2: &Sprite) -> bool {
     collided(sprite1, sprite2)
 }
 
 /// Check if the sprite is colliding with any sprite in the collection, and return a list of
 /// references to the sprites which are colliding
+#[must_use]
 pub fn check_for_collision_with_collection<'a>(
     sprite: &Sprite,
     list: &'a SpriteCollection,

src/vec2.rs

@@ -34,11 +34,13 @@ pub enum Direction {
 #[allow(clippy::enum_glob_use)]
 impl Direction {
     /// Flips this `Direction` around both the x- and y-axes.
+    #[must_use]
     pub fn flipped(self) -> Self {
         self.flip_x().flip_y()
     }
 
     /// Flips this `Direction` around the x-axis.
+    #[must_use]
     pub fn flip_x(self) -> Self {
         use Direction::*;
         match self {
@@ -49,6 +51,7 @@ impl Direction {
     }
 
     /// Flips this `Direction` around the y-axis.
+    #[must_use]
     pub fn flip_y(self) -> Self {
         use Direction::*;
         match self {
@@ -144,6 +147,7 @@ impl Vec2 {
     /// Creates a new `Vec2` with the given x- and y-values.
     ///
     /// It is often simpler, and preferred, to just write `(x, y).into()`.
+    #[must_use]
     pub const fn new(x: f32, y: f32) -> Vec2 {
         Self { x, y }
     }
@@ -151,11 +155,13 @@ impl Vec2 {
     /// Gets the squared magnitude of the vector.
     ///
     /// Useful for comparisons as it is faster to calculate than `magnitude`.
+    #[must_use]
     pub fn sq_magnitude(self) -> f32 {
         self.x * self.x + self.y * self.y
     }
 
     /// Gets the magnitude of the vector.
+    #[must_use]
     pub fn magnitude(self) -> f32 {
         self.sq_magnitude().sqrt()
     }
@@ -163,16 +169,19 @@ impl Vec2 {
     /// Gets the squared distance from this vector to `rhs`.
     ///
     /// Useful for comparisons as it is faster to calculate than `dist`.
+    #[must_use]
     pub fn sq_dist(self, rhs: Self) -> f32 {
         (self - rhs).sq_magnitude()
     }
 
     /// Gets the distance from this vector to `rhs`.
+    #[must_use]
     pub fn dist(self, rhs: Self) -> f32 {
         (self - rhs).magnitude()
     }
 
     /// Normalizes the vector, making its magnitude `1`.
+    #[must_use]
     pub fn normalized(self) -> Self {
         self / self.magnitude()
     }
@@ -180,6 +189,7 @@ impl Vec2 {
     /// Rounds the vector to a [`Vec2Int`].
     ///
     /// This uses `as i32` under the hood, and as such comes with all the same unfortunate edge cases. Beware.
+    #[must_use]
     pub fn rounded(self) -> Vec2Int {
         #[allow(clippy::cast_possible_truncation)]
         Vec2Int {
@@ -333,6 +343,7 @@ impl Vec2Int {
     /// Creates a new `Vec2` with the given x- and y-values.
     ///
     /// It is often simpler, and preferred, to just write `(x, y).into()`.
+    #[must_use]
     pub const fn new(x: i32, y: i32) -> Vec2Int {
         Self { x, y }
     }
@@ -340,11 +351,13 @@ impl Vec2Int {
     /// Gets the squared magnitude of the vector.
     ///
     /// Useful for comparisons as it is faster to calculate than `magnitude`.
+    #[must_use]
     pub fn sq_magnitude(self) -> i32 {
         self.x * self.x + self.y * self.y
     }
 
     /// Gets the magnitude of the vector.
+    #[must_use]
     pub fn magnitude(self) -> f32 {
         #[allow(clippy::cast_precision_loss)]
         (self.sq_magnitude() as f32).sqrt()
@@ -353,11 +366,13 @@ impl Vec2Int {
     /// Gets the squared distance from this vector to `rhs`.
     ///
     /// Useful for comparisons as it is faster to calculate than `dist`.
+    #[must_use]
     pub fn sq_dist(self, rhs: Self) -> i32 {
         (self - rhs).sq_magnitude()
     }
 
     /// Gets the distance from this vector to `rhs`.
+    #[must_use]
     pub fn dist(self, rhs: Self) -> f32 {
         (self - rhs).magnitude()
     }
@@ -365,6 +380,7 @@ impl Vec2Int {
     /// Casts this vector to a [`Vec2`].
     ///
     /// This uses `as f32` under the hood, and as such comes with all the same unfortunate edge cases. Beware.
+    #[must_use]
     pub fn to_f32(self) -> Vec2 {
         #[allow(clippy::cast_precision_loss)]
         Vec2 {