wip: and sweeps right through the codebase

layout/src/direction.rs

@@ -3,10 +3,32 @@ use crate::*;
 /// A cardinal direction.
 #[derive(Copy, Clone, PartialEq)]
 pub enum Direction { North, South, West, East, }
+
 pub use self::Direction::*;
 
 impl Direction {
-    #[inline]
+    pub fn is_north (&self) -> bool { matches!(self, Self::North) }
+    pub fn is_south (&self) -> bool { matches!(self, Self::South) }
+    pub fn is_east  (&self) -> bool { matches!(self, Self::West)  }
+    pub fn is_west  (&self) -> bool { matches!(self, Self::East)  }
+    /// Return next direction clockwise
+    pub fn cw (&self) -> Self {
+        match self {
+            Self::North => Self::East,
+            Self::South => Self::West,
+            Self::West  => Self::North,
+            Self::East  => Self::South,
+        }
+    }
+    /// Return next direction counterclockwise
+    pub fn ccw (&self) -> Self {
+        match self {
+            Self::North => Self::West,
+            Self::South => Self::East,
+            Self::West  => Self::South,
+            Self::East  => Self::North,
+        }
+    }
     pub fn split_fixed <N: Coordinate> (self, area: impl Area<N>, a: N) -> ([N;4],[N;4]) {
         match self {
             North => (