lwgeom_split_wrapx()

static LWGEOM* lwgeom_split_wrapx ( const LWGEOM *  geom_in, double  cutx, double  amount  )

static

Definition at line 37 of file lwgeom_wrapx.c.

References lwcollection_as_lwgeom(), lwcollection_free(), lwcollection_wrapx(), LWDEBUG, LWDEBUGF, LWDEBUGG, lwerror(), lwgeom_affine(), lwgeom_as_lwcollection(), lwgeom_clone_deep(), lwgeom_free(), lwgeom_geos_errmsg, lwgeom_get_bbox(), lwgeom_split(), lwgeom_unaryunion(), lwline_as_lwgeom(), lwline_construct(), lwnotice(), ptarray_construct(), ptarray_set_point4d(), LWGEOM::srid, POINT4D::x, GBOX::xmax, GBOX::xmin, POINT4D::y, GBOX::ymax, and GBOX::ymin.

Referenced by lwgeom_wrapx().

{
        LWGEOM *blade, *split;
        POINTARRAY *bladepa;
        POINT4D pt;
        const GBOX *box_in;
        AFFINE affine = {
                1, 0, 0,
                0, 1, 0,
                0, 0, 1,
                amount, 0, 0,
        };

        /* Extract box */
        /* TODO: check if the bbox should be force-recomputed */
        box_in = lwgeom_get_bbox(geom_in);
        if ( ! box_in ) {
                /* must be empty */
                return lwgeom_clone_deep(geom_in);
        }

        LWDEBUGF(2, "BOX X range is %g..%g, cutx:%g, amount:%g", box_in->xmin, box_in->xmax, cutx, amount);

        /* Check if geometry is fully on the side needing shift */
        if ( ( amount < 0 && box_in->xmin >= cutx ) || ( amount > 0 && box_in->xmax <= cutx ) )
        {
                split = lwgeom_clone_deep(geom_in);
                lwgeom_affine(split, &affine);
                LWDEBUGG(2, split, "returning the translated geometry");
                return split;
        }

        /* Check if geometry is fully on the side needing no shift */
        if ( ( amount < 0 && box_in->xmax <= cutx ) || ( amount > 0 && box_in->xmin >= cutx ) )
        {
                split = lwgeom_clone_deep(geom_in);
                LWDEBUGG(2, split, "returning the cloned geometry");
                return split;
        }

        /* We need splitting here */

        /* construct blade */
        bladepa = ptarray_construct(0, 0, 2);
        pt.x = cutx;
        pt.y = box_in->ymin - 1;
        ptarray_set_point4d(bladepa, 0, &pt);
        pt.y = box_in->ymax + 1;
        ptarray_set_point4d(bladepa, 1, &pt);
        blade = lwline_as_lwgeom(lwline_construct(geom_in->srid, NULL, bladepa));

        LWDEBUG(2, "splitting the geometry");

        /* split by blade */
        split = lwgeom_split(geom_in, blade);
        lwgeom_free(blade);
        if ( ! split ) {
                lwerror("%s:%d - lwgeom_split_wrapx:  %s", __FILE__, __LINE__, lwgeom_geos_errmsg);
                return NULL;
        }
        LWDEBUGG(2, split, "split geometry");


        /* iterate over components, translate if needed */
        const LWCOLLECTION *col = lwgeom_as_lwcollection(split);
        if ( ! col ) {
                /* not split, this is unexpected */
                lwnotice("WARNING: unexpected lack of split in lwgeom_split_wrapx");
                return lwgeom_clone_deep(geom_in);
        }
        LWCOLLECTION *col_out = lwcollection_wrapx(col, cutx, amount);
        lwgeom_free(split);

        /* unary-union the result (homogenize too ?) */
        LWGEOM* out = lwgeom_unaryunion(lwcollection_as_lwgeom(col_out));
        LWDEBUGF(2, "col_out:%p, unaryunion_out:%p", col_out, out);
        LWDEBUGG(2, out, "unary-unioned");

        lwcollection_free(col_out);

        return out;
}

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