scancache.h

#ifndef SCANCACHE_H
#define SCANCACHE_H

/*
 * Set the number of scan entries per cache.  This should be large
 * enough to read all points for any scan.
 */
#define SCAN_CACHE_SIZE 100

typedef struct {
  unsigned long index; /* The integer counter of this point in the scan */
  double azoff;        /* The AZ offset (degrees) */
  double eloff;        /* The EL offset (degrees) */
  double dkoff;        /* The DK offset (degrees) */
} ScanCacheEntry;

typedef struct {
  ScanCacheEntry cache[SCAN_CACHE_SIZE];
  unsigned int size;
  unsigned currentIndex;
} ScanCache;

int empty_ScanCache(ScanCache* cache);

int extend_ScanCache(ScanCache* cache, unsigned long index, double azoff, 
                     double eloff, double dkoff);

int get_ScanCache(ScanCache* cache, double* azoff, double* eloff, 
                  double* dkoff, bool* active);

#endif