Making sense of cycling dynamics left_power_phase*, right_power_phase*

Greetings,

  I'm trying to understand the FIT_RECORD_MESG struct values of left_power_phase and right_power_phase (and their _peak siblings). The documentation/marketing material for power phase says, that the power phase has a start angle and an end angle.

The power phase fields in the struct are defined as follows:

typedef struct
{
   ...
   FIT_UINT8 left_power_phase[FIT_RECORD_MESG_LEFT_POWER_PHASE_COUNT]; 
   FIT_UINT8 left_power_phase_peak[FIT_RECORD_MESG_LEFT_POWER_PHASE_PEAK_COUNT]; 
   FIT_UINT8 right_power_phase[FIT_RECORD_MESG_RIGHT_POWER_PHASE_COUNT]; 
   FIT_UINT8 right_power_phase_peak[FIT_RECORD_MESG_RIGHT_POWER_PHASE_PEAK_COUNT]; 
   ...
} FIT_RECORD_MESG;

and

#define FIT_RECORD_MESG_LEFT_POWER_PHASE_COUNT           1
#define FIT_RECORD_MESG_LEFT_POWER_PHASE_PEAK_COUNT      1
#define FIT_RECORD_MESG_RIGHT_POWER_PHASE_COUNT          1
#define FIT_RECORD_MESG_RIGHT_POWER_PHASE_PEAK_COUNT     1

So declared as arrays but with an element count of 1. So it's just one field, only one angle value.

The comment for the record fields says:

Data value indexes defined by power_phase_type.

and there are constants declared that I suppose are array indexes

typedef FIT_ENUM FIT_POWER_PHASE_TYPE;
#define FIT_POWER_PHASE_TYPE_INVALID                    FIT_ENUM_INVALID
#define FIT_POWER_PHASE_TYPE_POWER_PHASE_START_ANGLE    ((FIT_POWER_PHASE_TYPE)0)
#define FIT_POWER_PHASE_TYPE_POWER_PHASE_END_ANGLE      ((FIT_POWER_PHASE_TYPE)1)
#define FIT_POWER_PHASE_TYPE_POWER_PHASE_ARC_LENGTH     ((FIT_POWER_PHASE_TYPE)2)
#define FIT_POWER_PHASE_TYPE_POWER_PHASE_CENTER         ((FIT_POWER_PHASE_TYPE)3)
#define FIT_POWER_PHASE_TYPE_COUNT                      4

Seems like I'm missing something that has been configured differently for the SDK generator. Any idea what that is? The C++ implementation doesn't shed any light on this either.

Thanks for any pointers!

Herb