/* Last edited on 2005-06-05 12:40:28 by stolfi */

/* INDEX ROLL OPERATION - CORRECT BUT TOO CONFUSING TO BE USEFUL */

void ppv_roll ( ppv_array_t *A, ppv_axis_t i, ppv_axis_t j, int n );
  /* Modifies the descriptor {A} so that it describes the same samples
    as before, with indices {i..j} cyclically shifted by {n} places
    forward. Thus, element {A[c,h,v,d,t,u]} before the call
    {ppv_roll(A, 2,4, 1)} is equivalent to element {A[c,h,t,v,d,u]}
    after the call. 
    
    If the shift {n} is negative, or greater than {M=j-i+1}, it is
    reduced modulo {M} to the range {0..j-i}. */

void ppv_roll ( ppv_array_t *A, ppv_axis_t i, ppv_axis_t j, int n )
  { ix_roll(N, A->size, &(A->base), A->step, i, j, n); }

/* ERROR MESSAGES */

void ppv_progerror 
  ( const char *msg, 
    const char *file, 
    const unsigned int line, 
    const char* proc 
  );
  /* Prints {file ":" line ": (" *proc ")" *msg} to {stderr} and stops. */

#define ppv_error(msg) \
  ppv_progerror((msg), __FILE__, __LINE__, __FUNCTION__)
  /* Prints {*msg} and the source location.  */

  
void ppv_progerror 
  ( const char *msg, 
    const char *file, 
    const unsigned int line, 
    const char* proc 
  )
  { fprintf (stderr, "%s:%u: *** (%s) %s\n", file, line, proc, msg);
    exit(1);
  }