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return whether self_crossings mutated the bends

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Motiejus Jakštys 2021-03-11 17:35:11 +02:00
parent 4cd7cd0b11
commit 82a58a08bd
2 changed files with 17 additions and 6 deletions
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14
IV/tests.sql
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@ -46,8 +46,8 @@ insert into demo_inflections2 select name, generate_subscripts(ways, 1), unnest(
-- SELF-LINE CROSSING
drop table if exists selfcrossing, demo_selfcrossing3;
create table selfcrossing (name text, ways geometry[]);
insert into selfcrossing select name, self_crossing(ways) from inflections;
create table selfcrossing (name text, ways geometry[], mutated boolean);
insert into selfcrossing select name, (self_crossing(ways)).* from inflections;
create table demo_selfcrossing3 (name text, i bigint, way geometry);
insert into demo_selfcrossing3 select name, generate_subscripts(ways, 1), unnest(ways) from selfcrossing;
@ -88,9 +88,11 @@ end $$ language plpgsql;
do $$
declare
mutated boolean;
vcrossings geometry[];
begin
select self_crossing((select ways from inflections where name='fig6')) into vcrossings;
select (self_crossing((select ways from inflections where name='fig6'))).* into vcrossings, mutated;
perform assert_equals(true, mutated);
perform assert_equals(
'LINESTRING(84 47,91 59,114 64,120 45,125 39,141 39,147 32)',
(select st_astext(
@ -98,7 +100,8 @@ begin
) from (select unnest(vcrossings) way) a)
);
select self_crossing((select ways from inflections where name='fig6-rev')) into vcrossings;
select (self_crossing((select ways from inflections where name='fig6-rev'))).* into vcrossings, mutated;
perform assert_equals(true, mutated);
perform assert_equals(
'LINESTRING(84 47,91 59,114 64,120 45,125 39,141 39,147 32)',
(select st_astext(
@ -106,7 +109,8 @@ begin
) from (select unnest(vcrossings) way) a)
);
select self_crossing((select ways from inflections where name='fig6-combi')) into vcrossings;
select (self_crossing((select ways from inflections where name='fig6-combi'))).* into vcrossings, mutated;
perform assert_equals(true, mutated);
perform assert_equals(
'LINESTRING(84 137,91 149,114 154,120 135,125 129,141 129,147 122,164 137,171 149,194 154,200 135,205 129,221 129,227 122)',
(select st_astext(

9
IV/wm.sql
View File

@ -165,7 +165,10 @@ $$ language plpgsql;
-- self_crossing eliminates self-crossing from the bends, following the
-- article's section "Self-line Crossing When Cutting a Bend".
drop function if exists self_crossing;
create function self_crossing(INOUT bends geometry[]) as $$
create function self_crossing(
INOUT bends geometry[],
OUT mutated boolean
) as $$
declare
i int4;
j int4;
@ -182,6 +185,7 @@ declare
multi geometry;
begin
pi = radians(180);
mutated = false;
-- go through the bends and find one where sum of inflection angle is >180
for i in 1..array_length(bends, 1) loop
@ -227,6 +231,9 @@ begin
continue when st_numgeometries(multi) = 2 and
(st_contains(bends[j], a) or st_contains(bends[j], b));
-- stars are aligned, we are changing the bend
mutated = true;
-- Sincere apologies to someone who will need to debug the block below.
-- To understand it, I suggest you take a pencil and paper, draw a
-- self-crossing bend (fig6 from the article works well), and figure out