store size in tex instead of bot_right

src/core/position/pad.rs

@@ -74,6 +74,26 @@ impl Padding {
             bottom: amt,
         }
     }
+
+    pub fn with_top(mut self, amt: impl UiNum) -> Self {
+        self.top = amt.to_f32();
+        self
+    }
+
+    pub fn with_bottom(mut self, amt: impl UiNum) -> Self {
+        self.bottom = amt.to_f32();
+        self
+    }
+
+    pub fn with_left(mut self, amt: impl UiNum) -> Self {
+        self.left = amt.to_f32();
+        self
+    }
+
+    pub fn with_right(mut self, amt: impl UiNum) -> Self {
+        self.right = amt.to_f32();
+        self
+    }
 }
 
 impl<T: UiNum> From<T> for Padding {