add paddles that can move

src/engine/objs/geometry.rs

@@ -5,7 +5,7 @@ pub struct Position {
 }
 
 impl Position {
-    pub fn new(x: u32, y: u32) -> Self {
+    pub const fn new(x: u32, y: u32) -> Self {
         Self { x, y }
     }
 }

src/engine/objs/obj_traits.rs

@@ -38,4 +38,32 @@ pub trait MovingObject: Object {
         ctx.rect(prev_x, prev_y, width, height, BG);
         self.display(ctx);
     }
+
+    fn move_constrained(
+        &mut self,
+        x: i32,
+        y: i32,
+        constraint_start: Position,
+        constraint_end: Position,
+    ) {
+        let Position { x: cur_x, y: cur_y } = self.position();
+        let Size { width, height } = self.size();
+
+        let new_x = if cur_x.saturating_add_signed(x) <= constraint_start.x {
+            constraint_start.x
+        } else if (cur_x + width.saturating_add_signed(y)) > constraint_end.x {
+            constraint_end.x - width
+        } else {
+            cur_x.saturating_add_signed(x)
+        };
+
+        let new_y = if cur_y.saturating_add_signed(y) < constraint_start.y {
+            constraint_start.y
+        } else if (cur_y + height.saturating_add_signed(y)) >= constraint_end.y {
+            constraint_end.y - height
+        } else {
+            cur_y.saturating_add_signed(y)
+        };
+        self.update_pos(new_x, new_y)
+    }
 }

src/engine/objs/primitive_shapes.rs

@@ -10,7 +10,7 @@ pub struct Rect {
 }
 
 impl Rect {
-    pub fn new(x: u32, y: u32, height: u32, width: u32) -> Self {
+    pub fn new(x: u32, y: u32, width: u32, height: u32) -> Self {
         Self {
             pos: Position::new(x, y),
             size: Size::new(width, height),
@@ -42,10 +42,10 @@ pub struct MovingRect {
 }
 
 impl MovingRect {
-    pub fn new(x: u32, y: u32, height: u32, width: u32) -> Self {
+    pub fn new(x: u32, y: u32, width: u32, height: u32) -> Self {
         Self {
             prev_pos: Position::new(x, y),
-            current: Rect::new(x, y, height, width),
+            current: Rect::new(x, y, width, height),
         }
     }