/***************************************************************************
*
*  put_integer  -  puts integers into the byte stream.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Purpose:
*    This function copies a given number of 4 byte integers into the
*    byte stream. This function will convert the values to the correct
*    byte order if necessary.  The pointer into the buffer will be
*    advanced to the position immediately following the copied integers.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Parameters:
*
*    buf_ptr    <In/Out> == (char **) Address of pointer into byte stream
*    swap_bytes <Input>  == (int) 1 if bytes need to be swapped   
*    num_ints   <Input>  == (int) Number of elements in int_vals array
*    int_vals   <Input>  == (int *) Pointer to array of integers
*
*    RETURN     <Output> == (void)
*
****************************************************************************/
void  put_integer (
    char  **buf_ptr,
    int     swap_bytes,
    int     num_ints,
    int    *int_vals
    )
{
    int     i;
    char   *to;
    char   *from;

    if (swap_bytes)
    {
        /* If required, we need to byte swap */
   
        to = *buf_ptr;
        from = (char *)int_vals;
        for (i = 0; i < num_ints; i++)
        {
            to[0] = from[3];
            to[1] = from[2];
            to[2] = from[1];
            to[3] = from[0];
            to   += 4;
            from += 4;
        }

    }
    else
    {
        /* Simply copy the data */

        memcpy (*buf_ptr, int_vals, num_ints * sizeof (int));
    }

    /* Advance the pointer */

    *buf_ptr += num_ints * sizeof (int);

    return;
}

/***************************************************************************
*
*  put_double  -  puts doubles into the byte stream.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Purpose:
*    This function copies a given number of 8 byte doubles into the byte
*    stream. This function will convert the values to the correct byte
*    order if necessary.  The pointer into the buffer will be advanced
*    to the position immediately following the copied doubles.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Parameters:
*
*    buf_ptr     <In/Out> == (char **) Address of pointer into byte stream
*    swap_bytes  <Input>  == (int) 1 if bytes need to be swapped   
*    num_doubles <Input>  == (int) Number of elements in double_vals array
*    double_vals <Input>  == (double *) Pointer to array of doubles
*
*    RETURN      <Output> == (void)
*
****************************************************************************/

void  put_double (
    char   **buf_ptr,
    int      swap_bytes,
    int      num_doubles,
    double  *double_vals
    )
{
    int      i;
    char    *from;
    char    *to;

    if (swap_bytes)
    {
        /* Operating system endian-ness does not match data,
        /* the double array needs to be byte swapped. */
   
        to = *buf_ptr;
        from = (char *)double_vals;
        for (i = 0; i < num_doubles; i++)
        {
            to[0] = from[7];
            to[1] = from[6];
            to[2] = from[5];
            to[3] = from[4];
            to[4] = from[3];
            to[5] = from[2];
            to[6] = from[1];
            to[7] = from[0];
            to   += 8;
            from += 8;
        }
    }
    else
    {
        /* Simply copy the data. */

        memcpy (*buf_ptr, double_vals, num_doubles * sizeof (double));
    }

    /* Advance the pointer. */

    *buf_ptr += num_doubles * sizeof (double);

    return;
}

/***************************************************************************
*
*  put_xy  -  puts xy points into the byte stream.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Purpose:
*    This function copies a given number of xy double precision coordinates
*    into the byte stream.  This function will convert the values to the
*    correct byte order if necessary. The pointer into the buffer will be
*    advanced to the position immediately following the requested points.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Parameters:
*    buf_ptr     <In/Out> == (char **) Address of pointer into byte stream
*    swap_bytes  <Input>  == (int) 1 if bytes need to be swapped   
*    num_points  <Input>  == (int) Number of elements in points array
*    points      <Input>  == (Point *) Pointer to array of points
*
*    RETURN      <Output> == (void)
*
****************************************************************************/

void  put_xy (
    char  **buf_ptr,
    int     swap_bytes,
    int     num_points,
    Point  *points
    )
{
    int     i;
    char   *from;
    char   *to;
    Point  *pt;

    if (swap_bytes)
    {
        /* Operating system endian-ness does not match data,
        /* so the point array needs be byte swapped. */
   
        to = *buf_ptr;
        pt = points;
        for (i = 0; i < num_points; i++)
        {
            /* swap X value */

            from = (char *)&pt->x;
            to[0] = from[7];
            to[1] = from[6];
            to[2] = from[5];
            to[3] = from[4];
            to[4] = from[3];
            to[5] = from[2];
            to[6] = from[1];
            to[7] = from[0];

            /* swap Y value */

            from   = (char *)&pt->y;
            to += 8;
            to[0] = from[7];
            to[1] = from[6];
            to[2] = from[5];
            to[3] = from[4];
            to[4] = from[3];
            to[5] = from[2];
            to[6] = from[1];
            to[7] = from[0];

            to += 8;
            pt++;
        }
    }
    else
    {
        /* Simply copy the data. */
        memcpy (*buf_ptr, points, num_points * sizeof (Point));
    }

    /* Advance the pointer. */
    *buf_ptr += num_points * sizeof (Point);

    return;
}


/***************************************************************************
*
*  get_integer  -  gets integers from the byte stream.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Purpose:
*    This function extracts a given number of 4 byte integers
*    from the byte stream. This function will byte swap if necessary.
*    The pointer into the buffer will be advanced to the position
*    immediately following the requested integers.
*E
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Parameters:
*    buf_ptr    <In/Out> == (char **) Address of pointer into byte stream
*    swap_bytes <Input>  == (int) 1 if bytes need to be swapped   
*    num_ints   <Input>  == (int) Number of elements in int_vals array
*    int_vals   <Input>  == (int *) Pointer to array of integers
*
*    RETURN     <Output> == (void)
*
****************************************************************************/

void  get_integer (
    char  **buf_ptr,
    int     swap_bytes,
    int     num_ints,
    int    *int_vals
    )
{
    int     i;
    char   *to;
    char   *from;

    if (swap_bytes)
    {
        /* We need to byte swap */
        from = *buf_ptr;
        to = (char *)int_vals;
        for (i = 0; i < num_ints; i++)
        {
            to[0] = from[3];
            to[1] = from[2];
            to[2] = from[1];
            to[3] = from[0];
            to   += 4;
            from += 4;
        }

    }
    else
    {
        /* Simply copy the data */
        memcpy (int_vals, *buf_ptr, num_ints * sizeof (int));
    }

    /* Advance the pointer */
    *buf_ptr += num_ints * sizeof (int);

    return;
}

/***************************************************************************
*
*  get_double  -  gets doubles from the byte stream.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Purpose:
*    This function extracts a given number of 8 byte doubles
*    from the byte stream. This function will byte swap if necessary.
*    The pointer into the buffer will be advanced to the position
*    immediately following the requested doubles.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Parameters:
*    buf_ptr     <In/Out> == (char **) Address of pointer into byte stream
*    swap_bytes  <Input>  == (int) 1 if bytes need to be swapped   
*    num_doubles <Input>  == (int) Number of elements in double_vals array
*    double_vals <Input>  == (double *) Pointer to array of doubles
*
*    RETURN      <Output> == (void)
*
****************************************************************************/

void  get_double (
    char   **buf_ptr,
    int      swap_bytes,
    int      num_doubles,
    double  *double_vals
    )
{
    int      i;
    char    *from;
    char    *to;

    if (swap_bytes)
    {
        /* Operating system endian-ness does not match data,
        /* the double array needs to be byte swapped. */
   
        from = *buf_ptr;
        to   = (char *)double_vals;
        for (i = 0; i < num_doubles; i++)
        {
            to[0] = from[7];
            to[1] = from[6];
            to[2] = from[5];
            to[3] = from[4];
            to[4] = from[3];
            to[5] = from[2];
            to[6] = from[1];
            to[7] = from[0];
            to   += 8;
            from += 8;
        }
    }
    else
    {
        /* Simply copy the data. */

        memcpy (double_vals, *buf_ptr, num_doubles * sizeof (double));
    }

    /* Advance the pointer. */

    *buf_ptr += num_doubles * sizeof (double);

    return;
}

/***************************************************************************
*
*  get_xy  -  Gets xy points from the byte stream.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Purpose:
*    This function extracts a given number of xy double precision
*    coordinates from the byte stream. This function will byte swap
*    if necessary.  The pointer into the buffer will be advanced to
*    the position immediately following the requested points.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Parameters:
*    buf_ptr     <In/Out> == (char **) Address of pointer into byte stream
*    swap_bytes  <Input>  == (int) 1 if bytes need to be swapped   
*    num_points  <Input>  == (int) Number of elements in points array
*    points      <Output> == (Point *) Pointer to array of points
*
*    RETURN      <Output> == (void)
*
****************************************************************************/

void  get_xy (
    char  **buf_ptr,
    int     swap_bytes,
    int     num_points,
    Point  *points
    )
{
    int     i;
    char   *from;
    char   *to;
    Point  *pt;

    if (swap_bytes)
    {
        /* Operating system endian-ness does not match data,
        /* so the point array needs be byte swapped. */
   
        from = *buf_ptr;
        pt = points;

        for (i = 0; i < num_points; i++)
        {
            /* swap X value */

            to = (char *)&pt->x;
            to[0] = from[7];
            to[1] = from[6];
            to[2] = from[5];
            to[3] = from[4];
            to[4] = from[3];
            to[5] = from[2];
            to[6] = from[1];
            to[7] = from[0];

            /* swap Y value */

            to   = (char *)&pt->y;
            from += 8;
            to[0] = from[7];
            to[1] = from[6];
            to[2] = from[5];
            to[3] = from[4];
            to[4] = from[3];
            to[5] = from[2];
            to[6] = from[1];
            to[7] = from[0];

            from += 8;
            pt++;
        }
    }
    else
    {
        /* Simply copy the data. */
        memcpy (points, *buf_ptr, num_points * sizeof (Point));
    }

    /* Advance the pointer. */
    *buf_ptr += num_points * sizeof (Point);

    return;
}


/***********************************************************************
*
*  geom_allocate - Allocates or reallocates a geometry's point,
*                  z and/or m buffers.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Purpose:
*    This function allocates the point buffers of the given geometry
*    to the specified size. If the buffers are already allocated and
*    they are currently smaller than the specified size they will be
*    reallocated to the larger size (plus an additional number of
*    points to prevent the need to realloc for just a couple of points).
*    If the specified size is smaller than the currently allocated size
*    nothing will be done.
*   
*    The geometry type is examined to see if Z and/or M values are
*    specified, and the Z and/or M buffers are allocated or reallocated
*    in the same way as the point buffer.
*
*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*
*  Parameters:
*    geom         <In/Out> == (Geometry *) A geometry object
*                             to allocate the point buffers for.
*    npoints       <Input> == (int) The size to allocate the point 
*                             buffers to allocate/reallocate.
*
*    RETURN       <Output> == (int) Error code
*
***********************************************************************/

int geom_allocate(
    Geometry *geom,
    int       npoints
    )
{
    int     allocPerformed = 0;
    int     newAllocSize;
    double *newArray;
    Point  *newPoints;
    int     need_m;
    int     need_z;
    
    need_m = geom->type & 0x01;
    need_z = geom->type & 0x02;

    if (geom->alloc_size < npoints || geom->alloc_size == 0)
    {
       /* 
        * We have to increase the buffer sizes, make sure that 
        * we the newly allocated size is bigger at least by 
        * the POINT_ALLOC_THRESHOLD value. 
        */
        if (npoints > (geom->alloc_size + POINT_ALLOC_THRESHOLD))
            newAllocSize = npoints;
        else
            newAllocSize = geom->alloc_size + POINT_ALLOC_THRESHOLD;
    }
    else
    {
        /* We don't have to increase the buffer sizes */
        newAllocSize = geom->alloc_size;
    }
    
    if (geom->pt == NULL)
    {
        /* Allocate a new array of XY points */
        geom->pt = malloc (newAllocSize * sizeof(Point));
        if (geom->pt == NULL)
            return GEOM_OUT_OF_MEMORY;

        allocPerformed = 1;
    }
    else if (npoints > geom->alloc_size)
    {
        /* Reallocate an array of XY points */
        newPoints = malloc (newAllocSize * sizeof(Point));
        if (newPoints == NULL)
            return GEOM_OUT_OF_MEMORY;
        
        memcpy (newPoints, geom->pt, geom->alloc_size * sizeof(Point));
        free (geom->pt);
        geom->pt = newPoints;
        allocPerformed = 1;
    }

    if (need_z)
    {
        if (geom->z == NULL)
        {
            /* Allocate a new array of Z values */
            geom->z = malloc (newAllocSize * sizeof(double));
            if (geom->z == NULL)
                return GEOM_OUT_OF_MEMORY;

            allocPerformed = 1;
        }
        else if (npoints > geom->alloc_size)
        {
            /* Reallocate an array of Z values */
            newArray = malloc (newAllocSize * sizeof(double));
            if (newArray == NULL)
                return GEOM_OUT_OF_MEMORY;
        
            memcpy (newArray, geom->z, geom->alloc_size * sizeof(double));
            free (geom->z);
            geom->z = newArray;
            allocPerformed = 1;
        }
    }
    
    if (need_m)
    {
        if (geom->m == NULL)
        {
            /* Allocate a new array of M values */
            geom->m = malloc (newAllocSize * sizeof(double));
            if (geom->m == NULL)
                return GEOM_OUT_OF_MEMORY;

            allocPerformed = 1;
        }
        else if (npoints > geom->alloc_size)
        {
            /* Reallocate an array of M values */
            newArray = malloc (newAllocSize * sizeof(double));
            if (newArray == NULL)
                return GEOM_OUT_OF_MEMORY;
        
            memcpy (newArray, geom->m, geom->alloc_size * sizeof(double));
            free (geom->m);
            geom->m = newArray;
            allocPerformed = 1;
        }
    }

   /* 
    * If we allocated or reallocated the buffers, increase the 
    * allocated size.
    */
    if (allocPerformed)
        geom->alloc_size = newAllocSize;

    return GEOM_SUCCESS;
}