1 files changed, 78 insertions, 0 deletions
diff --git a/lib/dihedral_inf.h b/lib/dihedral_inf.h
new file mode 100644
index 0000000..f7c4297
--- /dev/null
+++ b/lib/dihedral_inf.h
@@ -0,0 +1,78 @@
+
+#include "types.h"
+#include <cmath>
+#include "height.h"
+
+template <class T>
+struct dihedral_inf_t { bool is_reflection; T x; };
+
+template <class T>
+void init(dihedral_inf_t<T> *ptr) {
+  ptr->is_reflection = false;
+  ptr->x = (T)0;
+}
+
+template <class T>
+dihedral_inf_t<T> copy(dihedral_inf_t<T> r) {
+  return r;
+}
+
+template <class T>
+void free_spin(dihedral_inf_t<T> r) {
+  // do nothing!
+}
+
+template <class T>
+height_t<T> act(dihedral_inf_t<T> r, height_t<T> h) {
+  height_t<T> h2;
+  if (r.is_reflection) {
+    h2.x = r.x - h.x;
+  } else {
+    h2.x = r.x + h.x;
+  }
+
+  return h2;
+}
+
+template <class T>
+dihedral_inf_t<T> act(dihedral_inf_t<T> r1, dihedral_inf_t<T> r2) {
+  dihedral_inf_t<T> r3;
+
+  if (r1.is_reflection) {
+    r3.is_reflection = !(r2.is_reflection);
+    r3.x = r1.x - r2.x;
+  } else {
+    r3.is_reflection = r2.is_reflection;
+    r3.x = r1.x + r2.x;
+  }
+
+  return r3;
+}
+
+template <class T>
+height_t<T> act_inverse(dihedral_inf_t<T> r, height_t<T> h) {
+  height_t<T> h2;
+  if (r.is_reflection) {
+    h2.x = r.x - h.x;
+  } else {
+    h2.x = h.x - r.x;
+  }
+
+  return h2;
+}
+
+template <class T>
+dihedral_inf_t<T> act_inverse(dihedral_inf_t<T> r1, dihedral_inf_t<T> r2) {
+  dihedral_inf_t<T> r3;
+
+  if (r1.is_reflection) {
+    r3.is_reflection = !(r2.is_reflection);
+    r3.x = r1.x - r2.x;
+  } else {
+    r3.is_reflection = r2.is_reflection;
+    r3.x = r2.x - r1.x;
+  }
+
+  return r3;
+}
+