write up joint-indexes.rst

joint-indexes.rst

@@ -1,4 +1,50 @@
 .. _joint_indexes:
 
 Joint Indexes
-#############
+#############
+
+The list at the bottom shows the joint indexes copied from `Joints.msg`.
+
+An example of accessing an angle for a specific joint:
+
+.. code-block:: cpp
+
+    joints.angles[nao_interfaces::msg::Joints::HEADYAW]
+
+``nao_interfaces::msg::Joints::NUM_JOINTS`` can be for iterating over all joints, as following:
+
+.. code-block:: cpp
+
+    for (unsigned i = 0; i < nao_interfaces::msg::Joints::NUMJOINTS; ++i)
+    {
+        // do something for each joint
+    }
+
+.. code-block:: cpp
+
+    int32 HEADYAW=0
+    int32 HEADPITCH=1
+    int32 LSHOULDERPITCH=2
+    int32 LSHOULDERROLL=3
+    int32 LELBOWYAW=4
+    int32 LELBOWROLL=5
+    int32 LWRISTYAW=6
+    int32 LHIPYAWPITCH=7
+    int32 LHIPROLL=8
+    int32 LHIPPITCH=9
+    int32 LKNEEPITCH=10
+    int32 LANKLEPITCH=11
+    int32 LANKLEROLL=12
+    int32 RHIPROLL=13
+    int32 RHIPPITCH=14
+    int32 RKNEEPITCH=15
+    int32 RANKLEPITCH=16
+    int32 RANKLEROLL=17
+    int32 RSHOULDERPITCH=18
+    int32 RSHOULDERROLL=19
+    int32 RELBOWYAW=20
+    int32 RELBOWROLL=21
+    int32 RWRISTYAW=22
+    int32 LHAND=23
+    int32 RHAND=24
+    int32 NUMJOINTS=25