add Alignment2d, better docs

hui/src/element/builtin/container.rs

@@ -1,10 +1,6 @@
 use glam::{Vec2, vec2, Vec4};
 use crate::{
-  layout::{Alignment, LayoutInfo, UiDirection, UiSize},
+  draw::{RoundedCorners, UiDrawCommand}, element::{MeasureContext, ProcessContext, UiElement}, layout::{Alignment, Alignment2d, LayoutInfo, UiDirection, UiSize}, measure::{Hints, Response}, rectangle::{Corners, Sides}
-  rectangle::{Corners, Sides},
-  draw::{RoundedCorners, UiDrawCommand},
-  element::{MeasureContext, ProcessContext, UiElement},
-  measure::{Hints, Response},
 };
 
 pub struct Border {
@@ -21,12 +17,12 @@ pub struct Container {
   pub gap: f32,
   pub padding: Sides<f32>,
   ///Primary/secondary axis
-  pub align: (Alignment, Alignment),
+  pub align: Alignment2d,
   pub background: Option<Vec4>,
   pub borders: Sides<Option<Border>>,
+  pub corner_radius: Option<Corners<f32>>,
   //pub clip: bool, //TODO clip children
   pub elements: Vec<Box<dyn UiElement>>,
-  pub corner_radius: Option<Corners<f32>>,
 }
 
 impl Default for Container {
@@ -39,7 +35,7 @@ impl Default for Container {
       //reverse: false,
       gap: 0.,
       padding: Sides::all(0.),
-      align: (Alignment::Begin, Alignment::Begin),
+      align: Alignment2d::default(),
       background: Default::default(),
       borders: Default::default(),
       elements: Vec::new(),

hui/src/layout.rs

@@ -2,14 +2,68 @@
 
 use glam::Vec2;
 
+/// Alignment along a single axis
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Default, PartialOrd, Ord)]
 pub enum Alignment {
+  /// Put the element at the beginning of the axis\
+  /// (left for horizontal, top for vertical alignment)
   #[default]
   Begin = 0,
+  /// Put the element in the center of the axis
   Center = 1,
+  /// Put the element at the end of the axis\
+  /// (right for horizontal, bottom for vertical alignment)
   End = 2,
 }
 
+/// Represents alignment in 2D space
+///
+/// - `horizontal` - alignment *along* x-axis (horizontal)\
+/// - `vertical` - alignment *along* y-axis (vertical)
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Default, PartialOrd, Ord)]
+pub struct Alignment2d {
+  /// Alignment *along* horizontal axis (X)
+  ///
+  /// ```text
+  /// ├───────[  ]──────┤
+  ///  ↑↑      ↑↑     ↑↑
+  /// Begin  Center  End
+  /// ```
+  pub horizontal: Alignment,
+
+  /// Alignment *along* vertical axis (Y)
+  ///
+  /// ```text
+  ///   ┬   ←─ Begin
+  ///   │
+  /// [   ] ←─ Center
+  ///   │
+  ///   ┴   ←─ End
+  /// ```
+  pub vertical: Alignment,
+}
+
+impl From<(Alignment, Alignment)> for Alignment2d {
+  fn from((horizontal, vertical): (Alignment, Alignment)) -> Self {
+    Self { horizontal, vertical }
+  }
+}
+
+impl From<[Alignment; 2]> for Alignment2d {
+  fn from([horizontal, vertical]: [Alignment; 2]) -> Self {
+    Self { horizontal, vertical }
+  }
+}
+
+impl From<Alignment> for Alignment2d {
+  fn from(alignment: Alignment) -> Self {
+    Self {
+      horizontal: alignment,
+      vertical: alignment,
+    }
+  }
+}
+
 #[derive(Default, Debug, Clone, Copy)]
 pub enum UiSize {
   #[default]