ptarray_from_wkb_state()

static POINTARRAY* ptarray_from_wkb_state ( wkb_parse_state *  s )

static

POINTARRAY Read a dynamically sized point array and advance the parse state forward.

First read the number of points, then read the points.

Definition at line 329 of file lwin_wkb.c.

References double_from_wkb_state(), wkb_parse_state::has_m, wkb_parse_state::has_z, integer_from_wkb_state(), LWDEBUGF, lwerror(), wkb_parse_state::pos, ptarray_construct(), ptarray_construct_copy_data(), POINTARRAY::serialized_pointlist, wkb_parse_state::swap_bytes, WKB_DOUBLE_SIZE, and wkb_parse_state_check().

Referenced by lwcircstring_from_wkb_state(), lwline_from_wkb_state(), lwpoly_from_wkb_state(), and lwtriangle_from_wkb_state().

{
        POINTARRAY *pa = NULL;
        size_t pa_size;
        uint32_t ndims = 2;
        uint32_t npoints = 0;
        static uint32_t maxpoints = 4294967295 / WKB_DOUBLE_SIZE / 4;

        /* Calculate the size of this point array. */
        npoints = integer_from_wkb_state(s);
        if (npoints > maxpoints)
        {
                lwerror("point array length (%d) is too large");
        }

        LWDEBUGF(4,"Pointarray has %d points", npoints);

        if( s->has_z ) ndims++;
        if( s->has_m ) ndims++;
        pa_size = npoints * ndims * WKB_DOUBLE_SIZE;

        /* Empty! */
        if( npoints == 0 )
                return ptarray_construct(s->has_z, s->has_m, npoints);

        /* Does the data we want to read exist? */
        wkb_parse_state_check(s, pa_size);

        /* If we're in a native endianness, we can just copy the data directly! */
        if( ! s->swap_bytes )
        {
                pa = ptarray_construct_copy_data(s->has_z, s->has_m, npoints, (uint8_t*)s->pos);
                s->pos += pa_size;
        }
        /* Otherwise we have to read each double, separately. */
        else
        {
                int i = 0;
                double *dlist;
                pa = ptarray_construct(s->has_z, s->has_m, npoints);
                dlist = (double*)(pa->serialized_pointlist);
                for( i = 0; i < npoints * ndims; i++ )
                {
                        dlist[i] = double_from_wkb_state(s);
                }
        }

        return pa;
}

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