Added tweak up and tweak down buttons.

Next up, add a bunch of extra nodes.

Change-Id: I4c2df145298567e61e8c36760be88f59a391588b
diff --git a/y2018/control_loops/python/graph_codegen.py b/y2018/control_loops/python/graph_codegen.py
index 5559f7c..abe5ed3 100644
--- a/y2018/control_loops/python/graph_codegen.py
+++ b/y2018/control_loops/python/graph_codegen.py
@@ -117,6 +117,26 @@
             % (numpy.pi / 2.0 - point[0][0], numpy.pi / 2.0 - point[0][1]))
         h_file.append("}")
 
+    front_points = [
+        index_function_name(point[1]) + "()" for point in graph_generate.front_points
+    ]
+    h_file.append("")
+    h_file.append("constexpr ::std::array<uint32_t, %d> FrontPoints() {" %
+                  len(front_points))
+    h_file.append("  return ::std::array<uint32_t, %d>{{%s}};" %
+                  (len(front_points), ", ".join(front_points)))
+    h_file.append("}")
+
+    back_points = [
+        index_function_name(point[1]) + "()" for point in graph_generate.back_points
+    ]
+    h_file.append("")
+    h_file.append("constexpr ::std::array<uint32_t, %d> BackPoints() {" %
+                  len(back_points))
+    h_file.append("  return ::std::array<uint32_t, %d>{{%s}};" %
+                  (len(back_points), ", ".join(back_points)))
+    h_file.append("}")
+
     # Add the Make*Path functions.
     h_file.append("")
     cc_file.append("")