Introduce orientation_from_direction

src/util.c

@@ -507,3 +507,11 @@ ssize_t slurp(const char *path, char **buf) {
     }
     return (ssize_t)n;
 }
+
+/*
+ * Convert a direction to its corresponding orientation.
+ *
+ */
+orientation_t orientation_from_direction(direction_t direction) {
+    return (direction == D_LEFT || direction == D_RIGHT) ? HORIZ : VERT;
+}