Merge branch 'gdb10lt'

This breaks "test-rivers" for Nemunas.

IV/Makefile

@@ -1,8 +1,9 @@
 OSM ?= lithuania-latest.osm.pbf
-WHERE ?= name='Visinčia' OR name='Šalčia' OR name='Nemunas' OR name='Merkys'
-#WHERE ?= name like '%'
+RIVERFILTER = Visinčia|Šalčia|Nemunas
 SLIDES = slides-2021-03-29.pdf
 
+GDB10LT ?= $(wildcard GDB10LT-static-*.zip)
+
 # Max figure size (in meters) is when it's width is TEXTWIDTH_CM on scale 1:25k
 SCALEDWIDTH = $(shell awk '/^TEXTWIDTH_CM/{print 25000/100*$$3}' layer2img.py)
 
@@ -281,12 +282,20 @@ $(OSM):
 	wget http://download.geofabrik.de/europe/$@
 
 .PHONY: refresh-rivers
-refresh-rivers: aggregate-rivers.sql $(OSM) .faux_db ## Refresh rivers.sql from Open Street Maps
-	PGPASSWORD=osm osm2pgsql -c --multi-geometry -H 127.0.0.1 -d osm -U osm $(OSM)
-	bash db -v where="$(WHERE)" -f $<
+refresh-rivers: aggregate-rivers.sql .faux_db ## Refresh rivers.sql from GDB10LT
+	@if [ ! -f "$(GDB10LT)" ]; then \
+		echo "ERROR: GDB10LT-static-*.zip not found. Do GDB10LT=<...>"; \
+		exit 1; \
+	fi
+	mkdir -p .tmp/shp; unzip -d .tmp/shp "$(GDB10LT)" 'HIDRO_L.*'
+	shp2pgsql -s 3857 -d ".tmp/shp/HIDRO_L.shp" | \
+		awk '!/^INSERT/{print}; /^INSERT/&&/$(RIVERFILTER)/{print;next}' | \
+		bash ./db
+	bash db -f $<
 	(\
 		echo '-- Generated at $(shell TZ=UTC date +"%FT%TZ") on $(shell whoami)@$(shell hostname -f)'; \
-		echo '-- Select: $(WHERE)'; \
+		echo '-- Rivers: $(RIVERFILTER)'; \
 		docker exec wm-mj pg_dump --clean -Uosm osm -t wm_rivers | tr -d '\r' \
 	) > rivers.sql.tmp
 	mv rivers.sql.tmp rivers.sql
+	rm -fr .tmp/shp

IV/aggregate-rivers.sql

@@ -1,7 +1,7 @@
 /* Aggregates rivers by name and proximity. */
 drop function if exists aggregate_rivers;
 create function aggregate_rivers() returns table(
-  osm_id bigint,
+  id bigint,
   name text,
   way geometry
 ) as $$
@@ -12,7 +12,7 @@ declare
 begin
   while (select count(1) from wm_rivers_tmp) > 0 loop
     select * from wm_rivers_tmp limit 1 into c;
-    delete from wm_rivers_tmp a where a.osm_id = c.osm_id;
+    delete from wm_rivers_tmp a where a.id = c.id;
     changed = true;
     while changed loop
       changed = false;
@@ -22,11 +22,11 @@ begin
           st_dwithin(a.way, c.way, 500)
         ) loop
         c.way = st_linemerge(st_union(c.way, cc.way));
-        delete from wm_rivers_tmp a where a.osm_id = cc.osm_id;
+        delete from wm_rivers_tmp a where a.id = cc.id;
         changed = true;
       end loop;
     end loop; -- while changed
-    return query select c.osm_id, c.name, c.way;
+    return query select c.id, c.name, c.way;
   end loop; -- count(1) from wm_rivers_tmp > 0
   return;
 end
@@ -35,13 +35,12 @@ $$ language plpgsql;
 drop index if exists wm_rivers_tmp_id;
 drop index if exists wm_rivers_tmp_gix;
 drop table if exists wm_rivers_tmp;
-create temporary table wm_rivers_tmp (osm_id bigint, name text, way geometry);
-create index wm_rivers_tmp_id on wm_rivers_tmp(osm_id);
+create temporary table wm_rivers_tmp (id bigint, name text, way geometry);
+create index wm_rivers_tmp_id on wm_rivers_tmp(id);
 create index wm_rivers_tmp_gix on wm_rivers_tmp using gist(way) include(name);
 
 insert into wm_rivers_tmp
-  select p.osm_id, p.name, p.way from planet_osm_line p
-    where waterway in ('river', 'stream', 'canal') and :where;
+  select p.gid as id, p.vardas as name, p.geom as way from hidro_l p;
 
 drop table if exists wm_rivers;
 create table wm_rivers as (

IV/visuals.sql

@@ -68,16 +68,23 @@ 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
-      )
+    with multismall as (
+      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
+        )
+      ) ways
     )
+    -- protecting against very small bends that were cut
+    -- in the corner of the picture
+    select st_union(a.geom)
+    from st_dump((select ways from multismall)) a
+    where st_length(a.geom) >= 100
 ));
 
 do $$
@@ -110,7 +117,7 @@ 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);
-    geom3 = st_simplifywm((select way from wm_visuals where name='salvis'), i);
+    geom3 = st_simplifywm((select way from wm_visuals where name='salvis'), i, 50, 'salvis-' || i);
     insert into wm_visuals(name, way) values
       ('salvis-douglas-'     || i, geom1),
       ('salvis-douglas-'     || i || '-chaikin', st_chaikinsmoothing(geom1, 5)),

IV/wm.sql

@@ -335,7 +335,7 @@ create function wm_bend_attrs(
   dbggen integer default null
 ) returns wm_t_attrs[] as $$
 declare
-  isolation_threshold constant real default 0.5;
+  isolation_threshold constant real default 0.3;
   attrs wm_t_attrs[];
   attr wm_t_attrs;
   bend geometry;