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bugfix: remove leftover segment

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Motiejus Jakštys 2021-05-19 22:57:46 +03:00 committed by Motiejus Jakštys
parent 3efef0864d
commit 5657df8543
2 changed files with 9 additions and 26 deletions
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8
tests.sql
View File

@ -14,12 +14,12 @@ drop table if exists figures;
create table figures (name text, way geometry);
-- to "normalize" a new line:
-- select st_astext(st_snaptogrid(st_transscale(geometry, 80, 130, .3, .3), 1)) from f;
--insert into figures (name, way) values ('fig3',ST_GeomFromText('LINESTRING(0 0,12 0,13 4,20 2,20 0,32 0,33 10,38 16,43 15,44 10,44 0,60 0)'));
--insert into figures (name, way) values ('fig3-1',ST_GeomFromText('LINESTRING(0 0,12 0,13 4,20 2,20 0,32 0,33 10,38 16,43 15,44 10,44 0)'));
--insert into figures (name, way) values ('fig5',ST_GeomFromText('LINESTRING(0 39,19 52,27 77,26 104,41 115,49 115,65 103,65 75,53 45,63 15,91 0)'));
insert into figures (name, way) values ('fig3',ST_GeomFromText('LINESTRING(0 0,12 0,13 4,20 2,20 0,32 0,33 10,38 16,43 15,44 10,44 0,60 0)'));
insert into figures (name, way) values ('fig3-1',ST_GeomFromText('LINESTRING(0 0,12 0,13 4,20 2,20 0,32 0,33 10,38 16,43 15,44 10,44 0)'));
insert into figures (name, way) values ('fig5',ST_GeomFromText('LINESTRING(0 39,19 52,27 77,26 104,41 115,49 115,65 103,65 75,53 45,63 15,91 0)'));
insert into figures (name, way) values ('fig6',ST_GeomFromText('LINESTRING(84 47,91 59,114 64,122 80,116 92,110 93,106 106,117 118,136 107,135 76,120 45,125 39,141 39,147 32)'));
insert into figures (name, way) values ('fig6-rev',ST_Reverse(ST_Translate((select way from figures where name='fig6'), 80, 0)));
--insert into figures (name, way) values ('inflection-1',ST_GeomFromText('LINESTRING(110 24,114 20,133 20,145 15,145 0,136 5,123 7,114 7,111 2)'));
insert into figures (name, way) values ('inflection-1',ST_GeomFromText('LINESTRING(110 24,114 20,133 20,145 15,145 0,136 5,123 7,114 7,111 2)'));
drop table if exists debug;
create table debug (i bigint, way geometry);

27
wm.sql
View File

@ -220,49 +220,32 @@ begin
p2 = st_pointn(bends[j], 1);
p3 = st_pointn(bends[j], -1);
raise notice 'j: %, i: %', j, i;
-- do end vertices of bend[i] cross bend[j]?
a = st_pointn(bends[i], 1);
b = st_pointn(bends[i], -1);
multi = st_split(bends[j], st_makeline(a, b));
raise notice 'bends[i]: %', st_astext(bends[i]);
raise notice 'bends[j]: %', st_astext(bends[j]);
raise notice 'a: %, b: %', st_astext(a), st_astext(b);
raise notice 'multi: %', st_astext(multi);
continue when st_numgeometries(multi) = 1;
continue when st_numgeometries(multi) = 2 and
(st_contains(bends[j], a) or st_contains(bends[j], b));
-- real self-crossing detected! Remove it.
-- if j < i:
-- bends[j] = multi[1][1...n-1]; that will have all the vertices of
-- bends[j], except the crossing and what comes after it.
-- bends[j] = append(bends[j], bends[i][-1])
-- remove bends from bends[j+1] to bends[i] inclusive.
-- j := i+1
-- elif j > i:
-- bends[i-1] = st_removepoint(bends[i-1], -1)
-- bends[i] = bends[i][1]
-- bends[i] = append(bends[i], multi[2][2..n])
-- remove bends from bends[i+1] to bends[j] inclusive.
raise notice '';
prev_length = array_length(bends, 1);
if j < i then
-- remove first vertex of the following bend, because the last
-- segment is always duplicated with the i-th bend.
bends[i+1] = st_removepoint(bends[i+1], 0);
bends[j] = st_geometryn(multi, 1);
bends[j] = st_setpoint(bends[j], st_npoints(bends[j])-1,
st_pointn(bends[i], st_npoints(bends[i])));
bends = bends[1:j] || bends[i+1:prev_length];
j = i;
else
-- remove last vertex of the previous bend, because the last
-- segment is duplicated with the i'th bend.
bends[i-1] = st_removepoint(bends[i-1], st_npoints(bends[i-1])-1);
bends[i] = st_makeline(
st_pointn(bends[i], 1),
st_removepoint(st_geometryn(multi, st_numgeometries(multi)), 0)
);
--insert into debug select x.path[1], x.geom from st_dump(bends[i-1]) x;
bends = bends[1:i] || bends[j+1:prev_length];
end if;
j = j - prev_length + array_length(bends, 1);