test: add tests for centered_with_size

src/entity/pacman.rs

@@ -1,13 +1,13 @@
-use glam::Vec2;
+use glam::{UVec2, Vec2};
 
 use crate::constants::BOARD_PIXEL_OFFSET;
 use crate::entity::direction::Direction;
 use crate::entity::graph::{Graph, NodeId, Position, Traverser};
+use crate::helpers::centered_with_size;
 use crate::texture::animated::AnimatedTexture;
 use crate::texture::directional::DirectionalAnimatedTexture;
 use crate::texture::sprite::SpriteAtlas;
 use sdl2::keyboard::Keycode;
-use sdl2::rect::Rect;
 use sdl2::render::{Canvas, RenderTarget};
 use std::collections::HashMap;
 
@@ -71,15 +71,14 @@ impl Pacman {
             Position::BetweenNodes { from, to, traversed } => {
                 let from_pos = graph.get_node(from).unwrap().position;
                 let to_pos = graph.get_node(to).unwrap().position;
-                let weight = from_pos.distance(to_pos);
-                from_pos.lerp(to_pos, traversed / weight)
+                from_pos.lerp(to_pos, traversed / from_pos.distance(to_pos))
             }
         }
     }
 
     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 = Rect::new(pixel_pos.x - 8, pixel_pos.y - 8, 16, 16);
+        let dest = centered_with_size(pixel_pos, UVec2::new(16, 16));
         let is_stopped = self.traverser.position.is_stopped();
 
         if is_stopped {

src/helpers.rs

@@ -0,0 +1,51 @@
+use glam::{IVec2, UVec2};
+use sdl2::rect::Rect;
+
+pub fn centered_with_size(pixel_pos: IVec2, size: UVec2) -> Rect {
+    Rect::new(
+        pixel_pos.x - size.x as i32 / 2,
+        pixel_pos.y - size.y as i32 / 2,
+        size.x,
+        size.y,
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_centered_with_size_basic() {
+        let rect = centered_with_size(IVec2::new(100, 100), UVec2::new(50, 30));
+        assert_eq!(rect.origin(), (75, 85));
+        assert_eq!(rect.size(), (50, 30));
+    }
+
+    #[test]
+    fn test_centered_with_size_odd_dimensions() {
+        let rect = centered_with_size(IVec2::new(50, 50), UVec2::new(51, 31));
+        assert_eq!(rect.origin(), (25, 35));
+        assert_eq!(rect.size(), (51, 31));
+    }
+
+    #[test]
+    fn test_centered_with_size_zero_position() {
+        let rect = centered_with_size(IVec2::new(0, 0), UVec2::new(100, 100));
+        assert_eq!(rect.origin(), (-50, -50));
+        assert_eq!(rect.size(), (100, 100));
+    }
+
+    #[test]
+    fn test_centered_with_size_negative_position() {
+        let rect = centered_with_size(IVec2::new(-100, -50), UVec2::new(80, 40));
+        assert_eq!(rect.origin(), (-140, -70));
+        assert_eq!(rect.size(), (80, 40));
+    }
+
+    #[test]
+    fn test_centered_with_size_large_dimensions() {
+        let rect = centered_with_size(IVec2::new(1000, 1000), UVec2::new(1000, 1000));
+        assert_eq!(rect.origin(), (500, 500));
+        assert_eq!(rect.size(), (1000, 1000));
+    }
+}

src/lib.rs

@@ -7,5 +7,6 @@ pub mod constants;
 pub mod emscripten;
 pub mod entity;
 pub mod game;
+pub mod helpers;
 pub mod map;
 pub mod texture;

src/main.rs

@@ -56,6 +56,7 @@ mod constants;
 mod emscripten;
 mod entity;
 mod game;
+mod helpers;
 mod map;
 mod texture;