Physics refactored out

src/physics.rs

@@ -0,0 +1,34 @@
+use bevy::{ecs::component::Component, math::I64Vec2};
+
+const MAX_SPEED: i64 = 256;
+
+#[derive(Default, Debug, Component)]
+pub struct PhysicsBody2D {
+    pub pos: I64Vec2,
+    pub vel: I64Vec2,
+}
+
+impl PhysicsBody2D {
+    pub fn tick(&mut self) {
+        self.pos += self.vel;
+    }
+
+    pub fn add_vel(&mut self, force: I64Vec2) {
+        let mut vel = self.vel + force;
+        if vel.length_squared() >= MAX_SPEED.pow(2) {
+            let l = vel.length_squared();
+            let x = vel.x * vel.x;
+            let y = vel.y * vel.y;
+
+            vel.x = match vel.x {
+                ..0 => (x * -MAX_SPEED) / l,
+                _ => (x * MAX_SPEED) / l,
+            };
+            vel.y = match vel.y {
+                ..0 => (y * -MAX_SPEED) / l,
+                _ => (y * MAX_SPEED) / l,
+            };
+        }
+        self.vel = vel;
+    }
+}