ptarray_scroll_in_place()

int ptarray_scroll_in_place	(	POINTARRAY *	pa,
		const POINT4D *	pt
	)

Definition at line 2181 of file ptarray.c.

{
        POINTARRAY *tmp;
        int found;
        uint32_t it;
        int ptsize;
 
        if ( ! ptarray_is_closed_2d(pa) )
        {
                lwerror("ptarray_scroll_in_place: input POINTARRAY is not closed");
                return LW_FAILURE;
        }
 
        ptsize = ptarray_point_size(pa);
 
        /* Find the point in the array */
        found = 0;
        for ( it = 0; it < pa->npoints; ++it )
        {
                if ( ! memcmp(getPoint_internal(pa, it), pt, ptsize) )
                {
                        found = 1;
                        break;
                }
        }
 
        if ( ! found )
        {
                lwerror("ptarray_scroll_in_place: input POINTARRAY does not contain the given point");
                return LW_FAILURE;
        }
 
        if ( 0 == it )
        {
                /* Point is already the start/end point, just clone the input */
                return LW_SUCCESS;
        }
 
        /* TODO: reduce allocations */
        tmp = ptarray_construct(FLAGS_GET_Z(pa->flags), FLAGS_GET_M(pa->flags), pa->npoints);
 
        bzero(getPoint_internal(tmp, 0), ptsize * pa->npoints);
        /* Copy the block from found point to last point into the output array */
        memcpy(
                getPoint_internal(tmp, 0),
                getPoint_internal(pa, it),
                ptsize * ( pa->npoints - it )
        );
 
        /* Copy the block from second point to the found point into the last portion of the
   * return */
        memcpy(
                getPoint_internal(tmp, pa->npoints - it),
                getPoint_internal(pa, 1),
                ptsize * ( it )
        );
 
        /* Copy the resulting pointarray back to source one */
        memcpy(
                getPoint_internal(pa, 0),
                getPoint_internal(tmp, 0),
                ptsize * ( pa->npoints )
        );
 
        ptarray_free(tmp);
 
        return LW_SUCCESS;
}

References POINTARRAY::flags, FLAGS_GET_M, FLAGS_GET_Z, getPoint_internal(), LW_FAILURE, LW_SUCCESS, lwerror(), POINTARRAY::npoints, ptarray_construct(), ptarray_free(), ptarray_is_closed_2d(), and ptarray_point_size().

Referenced by _lwt_AddLine(), ST_Scroll(), and test_ptarray_scroll().

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