update comment

panda/src/putil/bamReader.cxx

@@ -399,8 +399,10 @@ read_handle(DatagramIterator &scan) {
 //  Description: The interface for reading a pointer to another object
 //               from a Bam file.  Objects reading themselves from a
 //               Bam file should call this when they expect to read a
-//               pointer, passing in the datagram iterator and a
-//               pointer to their own object, i.e. 'this'.
+//               pointer to some other object.  This function reads
+//               whatever is stored in the bam file to represent the
+//               pointer, and advances the datagram iterator
+//               accordingly.
 //
 //               Rather than returning a pointer immediately, this
 //               function reads the internal pointer information from

panda/src/putil/bamWriter.cxx

@@ -254,11 +254,11 @@ write_cdata(Datagram &packet, const PipelineCyclerBase &cycler) {
 //
 //               The writing object should call this prior to writing
 //               out a PointerToArray.  It will return true if the
-//               same pointer has been previously, in which case the
-//               writing object need do nothing further; or it will
-//               return false if this particular pointer has not yet
-//               been written, in which case the writing object must
-//               then write out the contents of the array.
+//               same pointer has been written previously, in which
+//               case the writing object need do nothing further; or
+//               it will return false if this particular pointer has
+//               not yet been written, in which case the writing
+//               object must then write out the contents of the array.
 //
 //               Also see the WRITE_PTA() macro, which consolidates
 //               the work that must be done to write a PTA.