ptarray_insert_point()

int ptarray_insert_point	(	POINTARRAY *	pa,
		const POINT4D *	p,
		uint32_t	where
	)

Insert a point into an existing POINTARRAY.

Zero is the index of the start of the array.

Definition at line 96 of file ptarray.c.

{
        size_t point_size = ptarray_point_size(pa);
        LWDEBUGF(5,"pa = %p; p = %p; where = %d", pa, p, where);
        LWDEBUGF(5,"pa->npoints = %d; pa->maxpoints = %d", pa->npoints, pa->maxpoints);
 
        if ( FLAGS_GET_READONLY(pa->flags) )
        {
                lwerror("ptarray_insert_point: called on read-only point array");
                return LW_FAILURE;
        }
 
        /* Error on invalid offset value */
        if ( where > pa->npoints )
        {
                lwerror("ptarray_insert_point: offset out of range (%d)", where);
                return LW_FAILURE;
        }
 
        /* If we have no storage, let's allocate some */
        if( pa->maxpoints == 0 || ! pa->serialized_pointlist )
        {
                pa->maxpoints = 32;
                pa->npoints = 0;
                pa->serialized_pointlist = lwalloc(ptarray_point_size(pa) * pa->maxpoints);
        }
 
        /* Error out if we have a bad situation */
        if ( pa->npoints > pa->maxpoints )
        {
                lwerror("npoints (%d) is greater than maxpoints (%d)", pa->npoints, pa->maxpoints);
                return LW_FAILURE;
        }
 
        /* Check if we have enough storage, add more if necessary */
        if( pa->npoints == pa->maxpoints )
        {
                pa->maxpoints *= 2;
                pa->serialized_pointlist = lwrealloc(pa->serialized_pointlist, ptarray_point_size(pa) * pa->maxpoints);
        }
 
        /* Make space to insert the new point */
        if( where < pa->npoints )
        {
                size_t copy_size = point_size * (pa->npoints - where);
                memmove(getPoint_internal(pa, where+1), getPoint_internal(pa, where), copy_size);
                LWDEBUGF(5,"copying %d bytes to start vertex %d from start vertex %d", copy_size, where+1, where);
        }
 
        /* We have one more point */
        ++pa->npoints;
 
        /* Copy the new point into the gap */
        ptarray_set_point4d(pa, where, p);
        LWDEBUGF(5,"copying new point to start vertex %d", point_size, where);
 
        return LW_SUCCESS;
}

References POINTARRAY::flags, FLAGS_GET_READONLY, getPoint_internal(), LW_FAILURE, LW_SUCCESS, lwalloc(), LWDEBUGF, lwerror(), lwrealloc(), POINTARRAY::maxpoints, POINTARRAY::npoints, ptarray_point_size(), ptarray_set_point4d(), and POINTARRAY::serialized_pointlist.

Referenced by _lwt_AddPoint(), geography_centroid_from_mpoly(), lwline_add_lwpoint(), ptarray_append_point(), test_ptarray_insert_point(), and test_trim_bits().

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