stud/IV/tests-rivers.sql
2021-04-18 23:31:33 +03:00

60 lines
1.6 KiB
PL/PgSQL

\i wm.sql
insert into wm_visuals(name, way) values('salcia-visincia',
st_closestpoint(
(select way from wm_rivers where name='Šalčia'),
(select way from wm_rivers where name='Visinčia')
)
);
insert into wm_visuals(name, way) values('nemunas-merkys',
st_closestpoint(
(select way from wm_rivers where name='Nemunas'),
(select way from wm_rivers where name='Merkys')
)
);
-- wm_envelope clips a geometry by a bounding box around a given object,
-- matching dimensions of A-class paper (1 by sqrt(2).
drop function if exists wm_bbox;
create function wm_bbox(
center text,
projection_scale integer,
projection_width_cm float
) returns geometry as $$
declare
gcenter geometry;
halfX float;
halfY float;
begin
halfX = projection_scale * projection_width_cm / 2 / 100;
halfY = halfX * sqrt(2);
select way from wm_visuals where name=center into gcenter;
if gcenter is null then
raise 'center % not found', center;
end if;
return st_envelope(
st_union(
st_translate(gcenter, halfX, halfY),
st_translate(gcenter, -halfX, -halfY)
)
);
end
$$ language plpgsql;
do $$
declare
npoints bigint;
secs bigint;
begin
select * from ST_SimplifyWM_Estimate((select st_union(way) from wm_rivers)) into npoints, secs;
raise notice 'Total points: %', npoints;
raise notice 'Expected duration: %s (+-%s)', ceil(secs), floor(secs*.5);
end $$ language plpgsql;
delete from wm_debug where name in (select distinct name from wm_rivers);
delete from wm_demo where name in (select distinct name from wm_rivers);
insert into wm_demo (name, way) select name, ST_SimplifyWM(way, name) from wm_rivers;