SQLite

/*
** A search constraint.
*/
struct RtreeConstraint {
  int iCoord;                     /* Index of constrained coordinate */
  int op;                         /* Constraining operation */
  union {
    RtreeDValue rValue;             /* Constraint value. */
    int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*);
    int (*xQueryFunc)(sqlite3_rtree_query_info*);
  } u;
  sqlite3_rtree_query_info *pGeom;  /* xGeom and xQueryFunc argument */
};

/* Possible values for RtreeConstraint.op */
#define RTREE_EQ    0x41
#define RTREE_LE    0x42
#define RTREE_LT    0x43
#define RTREE_GE    0x44
#define RTREE_GT    0x45
#define RTREE_MATCH 0x46  /* Old-style sqlite3_rtree_geometry_callback() */
#define RTREE_QUERY 0x47  /* New-style sqlite3_rtree_query_callback() */

/* 
** An rtree structure node.
*/
struct RtreeNode {
  RtreeNode *pParent;         /* Parent node */
  i64 iNode;                  /* The node number */

/*
** Free the RtreeCursor.aConstraint[] array and its contents.
*/
static void freeCursorConstraints(RtreeCursor *pCsr){
  if( pCsr->aConstraint ){
    int i;                        /* Used to iterate through constraint array */
    for(i=0; i<pCsr->nConstraint; i++){
      sqlite3_rtree_query_info *pGeom = pCsr->aConstraint[i].pGeom;
      if( pGeom ){
        if( pGeom->xDelUser ) pGeom->xDelUser(pGeom->pUser);
        sqlite3_free(pGeom);
      }
    }
    sqlite3_free(pCsr->aConstraint);
    pCsr->aConstraint = 0;

  assert( pConstraint->op==RTREE_MATCH );
  assert( pConstraint->pGeom );

  for(i=0; i<nCoord; i++){
    aCoord[i] = DCOORD(pCell->aCoord[i]);
  }
  return pConstraint->u.xGeom((sqlite3_rtree_geometry*)pConstraint->pGeom,
                              nCoord, aCoord, pbRes);
}

/* 
** Cursor pCursor currently points to a cell in a non-leaf page.
** Set *pbEof to true if the sub-tree headed by the cell is filtered
** (excluded) by the constraints in the pCursor->aConstraint[] 
** array, or false otherwise.

    assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
        || p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
    );

    switch( p->op ){
      case RTREE_LE: case RTREE_LT: 
        bRes = p->u.rValue<cell_min; 
        break;

      case RTREE_GE: case RTREE_GT: 
        bRes = p->u.rValue>cell_max; 
        break;

      case RTREE_EQ:
        bRes = (p->u.rValue>cell_max || p->u.rValue<cell_min);
        break;

      default: {
        assert( p->op==RTREE_MATCH );
        rc = testRtreeGeom(pRtree, p, &cell, &bRes);
        bRes = !bRes;
        break;

    RtreeConstraint *p = &pCursor->aConstraint[ii];
    RtreeDValue coord = DCOORD(cell.aCoord[p->iCoord]);
    int res;
    assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
        || p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
    );
    switch( p->op ){
      case RTREE_LE: res = (coord<=p->u.rValue); break;
      case RTREE_LT: res = (coord<p->u.rValue);  break;
      case RTREE_GE: res = (coord>=p->u.rValue); break;
      case RTREE_GT: res = (coord>p->u.rValue);  break;
      case RTREE_EQ: res = (coord==p->u.rValue); break;
      default: {
        int rc;
        assert( p->op==RTREE_MATCH );
        rc = testRtreeGeom(pRtree, p, &cell, &res);
        if( rc!=SQLITE_OK ){
          return rc;
        }

** This function is called to configure the RtreeConstraint object passed
** as the second argument for a MATCH constraint. The value passed as the
** first argument to this function is the right-hand operand to the MATCH
** operator.
*/
static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){
  RtreeMatchArg *p;
  sqlite3_rtree_query_info *pGeom;
  int nBlob;

  /* Check that value is actually a blob. */
  if( sqlite3_value_type(pValue)!=SQLITE_BLOB ) return SQLITE_ERROR;

  /* Check that the blob is roughly the right size. */
  nBlob = sqlite3_value_bytes(pValue);
  if( nBlob<(int)sizeof(RtreeMatchArg) 
   || ((nBlob-sizeof(RtreeMatchArg))%sizeof(RtreeDValue))!=0
  ){
    return SQLITE_ERROR;
  }

  pGeom = (sqlite3_rtree_query_info*)sqlite3_malloc( sizeof(*pGeom)+nBlob );


  if( !pGeom ) return SQLITE_NOMEM;
  memset(pGeom, 0, sizeof(*pGeom));
  p = (RtreeMatchArg*)&pGeom[1];

  memcpy(p, sqlite3_value_blob(pValue), nBlob);
  if( p->magic!=RTREE_GEOMETRY_MAGIC 
   || nBlob!=(int)(sizeof(RtreeMatchArg) + (p->nParam-1)*sizeof(RtreeDValue))
  ){
    sqlite3_free(pGeom);
    return SQLITE_ERROR;
  }

  pGeom->pContext = p->cb.pContext;
  pGeom->nParam = p->nParam;
  pGeom->aParam = p->aParam;

  pCons->u.xGeom = p->cb.xGeom;
  pCons->pGeom = pGeom;
  return SQLITE_OK;
}

/* 
** Rtree virtual table module xFilter method.
*/

            */
            rc = deserializeGeometry(argv[ii], p);
            if( rc!=SQLITE_OK ){
              break;
            }
          }else{
#ifdef SQLITE_RTREE_INT_ONLY
            p->u.rValue = sqlite3_value_int64(argv[ii]);
#else
            p->u.rValue = sqlite3_value_double(argv[ii]);
#endif
          }
        }
      }
    }
  
    if( rc==SQLITE_OK ){

);


/*
** A pointer to a structure of the following type is passed as the 
** argument to scored geometry callback registered using
** sqlite3_rtree_query_callback().
**
** Note that the first 5 fields of this structure are identical to
** sqlite3_rtree_geometry.  This structure is a subclass of
** sqlite3_rtree_geometry.
*/
struct sqlite3_rtree_query_info {
  void *pContext;                   /* pContext from when function registered */
  int nParam;                       /* Number of function parameters */
  sqlite3_rtree_dbl *aParam;        /* value of function parameters */
  void *pUser;                      /* callback can use this, if desired */
  void (*xDelUser)(void*);          /* function to free pUser */