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fix gentle inflections -- both tests pass

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Motiejus Jakštys 2021-05-19 22:57:45 +03:00 committed by Motiejus Jakštys
parent 236d0bcbf0
commit a63a6c51a9
2 changed files with 35 additions and 18 deletions
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28
tests.sql
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@ -43,20 +43,20 @@ end $$ language plpgsql;
drop table if exists inflections;
create table inflections (name text, way geometry);
--insert into inflections select 'fig3', unnest(fix_gentle_inflections(detect_bends((select way from figures where name='fig3'))));
insert into inflections select 'fig3', unnest(fix_gentle_inflections(detect_bends((select way from figures where name='fig3'))));
insert into inflections select 'fig5', unnest(fix_gentle_inflections(detect_bends((select way from figures where name='fig5'))));
--insert into inflections select 'inflection-1', unnest(fix_gentle_inflections(detect_bends((select way from figures where name='inflection-1'))));
insert into inflections select 'inflection-1', unnest(fix_gentle_inflections(detect_bends((select way from figures where name='inflection-1'))));
-- FIX BEND INFLECTIONS
--do $$
--declare
-- vbends geometry[];
-- vinflections geometry[];
--begin
-- select detect_bends((select way from figures where name='inflection-1')) into vbends;
-- select fix_gentle_inflections(vbends) into vinflections;
--
-- perform assert_equals(vbends[1], vinflections[1]); -- unchanged
-- perform assert_equals('LINESTRING(114 20,133 20,145 15,145 0,136 5,123 7,114 7)', st_astext(vinflections[2]));
-- perform assert_equals('LINESTRING(123 7,114 7,111 2)', st_astext(vinflections[3]));
--end $$ language plpgsql;
do $$
declare
vbends geometry[];
vinflections geometry[];
begin
select detect_bends((select way from figures where name='inflection-1')) into vbends;
select fix_gentle_inflections(vbends) into vinflections;
perform assert_equals(vbends[1], vinflections[1]); -- unchanged
perform assert_equals('LINESTRING(114 20,133 20,145 15,145 0,136 5,123 7,114 7)', st_astext(vinflections[2]));
perform assert_equals('LINESTRING(123 7,114 7,111 2)', st_astext(vinflections[3]));
end $$ language plpgsql;

25
wm.sql
View File

@ -76,10 +76,21 @@ $$ language plpgsql;
-- commulative inflection angle small (see variable below).
create or replace function fix_gentle_inflections(INOUT bends geometry[]) as $$
declare
len int4;
bends1 geometry[];
bends2 geometry[];
begin
len = array_length(bends, 1);
bends1 = fix_gentle_inflections1(bends);
bends1 = array_reverse(fix_gentle_inflections1(array_reverse(bends1)));
for i in 1..len loop
bends2[i] = st_reverse(bends1[len-i+1]);
end loop;
bends2 = fix_gentle_inflections1(bends2);
for i in 1..len loop
bends[i] = st_reverse(bends2[len-i+1]);
end loop;
end
$$ language plpgsql;
@ -134,13 +145,19 @@ begin
exit when array_length(phead, 1) < 3;
-- if inflection angle between ptail[1:3] "large", stop processing this bend
exit when abs(st_angle(phead[1], phead[2], phead[3]) - pi) > small_angle;
if abs(st_angle(phead[1], phead[2], phead[3]) - pi) > small_angle then
--raise notice 'quitting % because angle between % % %', st_astext(ptail), st_astext(phead[1]), st_astext(phead[2]), st_astext(phead[3]);
exit;
end if;
-- distance from head's first vertex should be larger than from second vertex
exit when st_distance(ptail, phead[2]) < st_distance(ptail, phead[3]);
if st_distance(ptail, phead[2]) < st_distance(ptail, phead[3]) then
--raise notice 'quitting % because distance', st_astext(ptail);
exit;
end if;
-- detected a gentle inflection. Move head of the tail to the tail of head
raise notice 'fixing a gentle inflection of angle %', degrees(abs(st_angle(phead[1], phead[2], phead[3]) - pi));
--raise notice 'fixing a gentle inflection of angle %', degrees(abs(st_angle(phead[1], phead[2], phead[3]) - pi));
bends[i] = st_removepoint(bends[i], 0);
bends[i-1] = st_addpoint(bends[i-1], phead[3]);