wm/test-rivers.sql

112 lines
2.9 KiB
PL/PgSQL

\i wm.sql
-- wm_bbox 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 geometry,
scaledwidth float
) returns geometry as $$
declare
halfX float;
halfY float;
begin
halfX = scaledwidth / 2;
halfY = halfX * sqrt(2);
return st_envelope(
st_union(
st_translate(center, halfX, halfY),
st_translate(center, -halfX, -halfY)
)
);
end $$ language plpgsql;
-- wm_quadrant divides the given geometry to 4 rectangles
-- and returns the requested quadrant following cartesian
-- convention:
-- +----------+
-- | II | I |
--- +----------+
-- | III | IV |
-- +-----+----+
-- matching dimensions of A-class paper (1 by sqrt(2).
drop function if exists wm_quadrant;
create function wm_quadrant(
geom geometry,
quadrant integer
) returns geometry as $$
declare
xmin float;
xmax float;
ymin float;
ymax float;
begin
xmin = st_xmin(geom);
xmax = st_xmax(geom);
ymin = st_ymin(geom);
ymax = st_ymax(geom);
if quadrant = 1 or quadrant = 2 then
ymin = (ymin + ymax)/2;
else
ymax = (ymin + ymax)/2;
end if;
if quadrant = 2 or quadrant = 3 then
xmax = (xmin + xmax)/2;
else
xmin = (xmin + xmax)/2;
end if;
return st_intersection(
geom,
st_makeenvelope(xmin, ymin, xmax, ymax, st_srid(geom))
);
end $$ language plpgsql;
delete from wm_visuals where name like 'salvis%';
insert into wm_visuals(name, way) values('salvis', (
select st_intersection(
(select st_union(way) from wm_rivers where name in ('Šalčia', 'Visinčia')),
wm_bbox(
st_closestpoint(
(select way from wm_rivers where name='Šalčia'),
(select way from wm_rivers where name='Visinčia')
),
:scaledwidth
)
)
));
do $$
declare
i integer;
geom1 geometry;
geom2 geometry;
begin
foreach i in array array[16, 64, 256] loop
geom1 = st_simplify((select way from wm_visuals where name='salvis'), i);
geom2 = st_simplifyvw((select way from wm_visuals where name='salvis'), i*i);
insert into wm_visuals(name, way) values
('salvis-douglas-' || i, geom1),
('salvis-douglas-' || i || '-chaikin', st_chaikinsmoothing(geom1, 5)),
('salvis-visvalingam-' || i, geom2),
('salvis-visvalingam-' || i || '-chaikin', st_chaikinsmoothing(geom2, 5));
end loop;
end $$ 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, 75, null, name) from wm_rivers;