move everything out of layout

core/src/num.rs

@@ -0,0 +1,49 @@
+use crate::util::Vec2;
+use std::marker::Destruct;
+
+pub const trait UiNum {
+    fn to_f32(self) -> f32;
+}
+
+impl const UiNum for f32 {
+    fn to_f32(self) -> f32 {
+        self
+    }
+}
+
+impl const UiNum for u32 {
+    fn to_f32(self) -> f32 {
+        self as f32
+    }
+}
+
+impl const UiNum for i32 {
+    fn to_f32(self) -> f32 {
+        self as f32
+    }
+}
+
+pub const fn vec2(x: impl const UiNum, y: impl const UiNum) -> Vec2 {
+    Vec2::new(x.to_f32(), y.to_f32())
+}
+
+impl<T: const UiNum + Copy> const From<T> for Vec2 {
+    fn from(v: T) -> Self {
+        Self {
+            x: v.to_f32(),
+            y: v.to_f32(),
+        }
+    }
+}
+
+impl<T: const UiNum, U: const UiNum> const From<(T, U)> for Vec2
+where
+    (T, U): const Destruct,
+{
+    fn from((x, y): (T, U)) -> Self {
+        Self {
+            x: x.to_f32(),
+            y: y.to_f32(),
+        }
+    }
+}