working with clipping/display of rivers

IV/Makefile

@@ -10,7 +10,8 @@ SLIDES = slides-2021-03-29.pdf
 NON_ARCHIVABLES = notes.txt referatui.txt slides-2021-03-29.txt
 ARCHIVABLES = $(filter-out $(NON_ARCHIVABLES),$(shell git ls-files .))
 
-FIGURES = test-figures \
+FIGURES = \
+		  test-figures \
 		  fig8-definition-of-a-bend \
 		  fig5-gentle-inflection-before \
 		  fig5-gentle-inflection-after \
@@ -21,6 +22,10 @@ FIGURES = test-figures \
 		  selfcrossing-1-before \
 		  selfcrossing-1-after
 
+RIVERS = \
+		 salvis-gdr10 \
+		 salvis-gdr50
+
 # paper sizes in mm
 A4p = 210x297
 A4l = 297x210
@@ -75,8 +80,9 @@ mj-msc.pdf: mj-msc.tex version.inc.tex vars.inc.tex bib.bib $(addsuffix .pdf,$(F
 ############################
 
 define FIG_template
-$(1).pdf: layer2img.py Makefile .faux_test
+$(1).pdf: layer2img.py Makefile $(2)
 	python ./layer2img.py --outfile=$(1).pdf \
+		$$(if $$($(1)_WMCLIP),--wmclip=$$($(1)_WMCLIP)) \
 		$$(if $$($(1)_WIDTHDIV),--widthdiv=$$($(1)_WIDTHDIV)) \
 		$$(foreach i,1 2 3, \
 			$$(if $$($(1)_$$(i)CMAP),--group$$(i)-cmap="$$($(1)_$$(i)CMAP)") \
@@ -84,7 +90,8 @@ $(1).pdf: layer2img.py Makefile .faux_test
 			$$(if $$($(1)_$$(i)LINESTYLE),--group$$(i)-linestyle="$$($(1)_$$(i)LINESTYLE)") \
 	)
 endef
-$(foreach fig,$(FIGURES),$(eval $(call FIG_template,$(fig))))
+$(foreach fig,$(FIGURES),$(eval $(call FIG_template,$(fig).faux_test)))
+$(foreach fig,$(RIVERS), $(eval $(call FIG_template,$(fig),.faux_test-rivers)))
 
 test-figures_1SELECT = wm_figures
 
@@ -128,6 +135,12 @@ selfcrossing-1-after_1SELECT = wm_debug where name='selfcrossing-1' AND stage='d
 selfcrossing-1-after_2SELECT = wm_debug where name='selfcrossing-1' AND stage='bbends' AND gen=1
 selfcrossing-1-after_2LINESTYLE = invisible
 
+salvis-gdr10_1SELECT = wm_rivers where name='Šalčia' OR name='Visinčia'
+salvis-gdr10_WMCLIP = salcia-visincia:GDR10
+
+salvis-gdr50_1SELECT = wm_rivers where name='Šalčia' OR name='Visinčia'
+salvis-gdr50_WMCLIP = salcia-visincia:GDR50
+
 
 .faux_test-rivers: tests-rivers.sql wm.sql .faux_db
 	./db -f $<

IV/layer2img.py

@@ -11,6 +11,7 @@ CMAP = 'tab20c'
 
 BOUNDS = ('xmin', 'ymin', 'xmax', 'ymax')
 INCH_MM = 25.4
+INCH_CM = INCH_MM / 10
 BLACK, GREEN, ORANGE, PURPLE = '#000000', '#1b9e77', '#d95f02', '#7570b3'
 PSQL_CREDS = "host=127.0.0.1 dbname=osm user=osm password=osm"
 
@@ -28,9 +29,9 @@ SCALES = {
 def wm_clip(string):
     if not string:
         return None
-    gdr, name = string.split(":")
+    name, gdr = string.split(":")
     if scale := SCALES.get(gdr):
-        return gdr, scale
+        return name, scale
     scales = ",".join(SCALES.keys())
     raise argparse.ArgumentTypeError("invalid scale. Expected %s" % scales)
 
@@ -51,7 +52,9 @@ def parse_args():
     parser.add_argument('--group3-linestyle')
 
     parser.add_argument('--wmclip',
-                        type=wm_clip, help="Clip. E.g. GDR10:nemunas-merkys")
+                        type=wm_clip,
+                        help="Clip for scale. E.g. salcia-visincia:GDR10",
+                        )
     parser.add_argument('--widthdiv',
                         default=1, type=float, help='Width divisor')
 
@@ -59,19 +62,20 @@ def parse_args():
     return parser.parse_args()
 
 
-def read_layer(select, width, maybe_wmclip):
+def read_layer(select, width_in, maybe_wmclip):
     if not select:
         return
     way = "way"
     if maybe_wmclip:
         name, scale = maybe_wmclip
-        way = "wm_clip(way, {name}, {scale}, {width})".format(
+        way = "st_intersection(way, wm_bbox('{name}', {scale}, {width}))".format(
                 name=name,
                 scale=scale,
-                width=width,
+                width=width_in * INCH_CM,
         )
     conn = psycopg2.connect(PSQL_CREDS)
     sql = "SELECT {way} as way1 FROM {select}".format(way=way, select=select)
+    print("sql: %s" % sql)
     return geopandas.read_postgis(sql, con=conn, geom_col='way1')
 
 
@@ -99,7 +103,7 @@ def main():
 
     rc('text', usetex=True)
     fig, ax = plt.subplots()
-    fig.set_figwidth(width)
+    #fig.set_figwidth(width)
 
     group1 is not None and group1.plot(ax=ax, **c1)
     group2 is not None and group2.plot(ax=ax, **c2)

IV/tests-rivers.sql

@@ -17,32 +17,30 @@ insert into wm_visuals(name, way) values('nemunas-merkys',
 
 -- wm_envelope 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_clip;
+drop function if exists wm_bbox;
-create function wm_clip(
+create function wm_bbox(
-  geom geometry,
   center text,
   projection_scale integer,
-  projection_width float
+  projection_width_cm float
 ) returns geometry as $$
 declare
   gcenter geometry;
-  bbox geometry;
   halfX float;
   halfY float;
 begin
-  halfX = projection_scale * projection_width / 2;
+  halfX = projection_scale * projection_width_cm / 2;
   halfY = halfX * sqrt(2);
   select way from wm_visuals where name=center into gcenter;
   if gcenter is null then
     raise 'center % not found', center;
   end if;
 
-  bbox = st_envelope(
+  return st_envelope(
-    st_project(gcenter, halfX, radians(90)),
+    st_union(
-    st_project(gcenter, halfY, 0)
+      st_translate(gcenter, halfX, halfY),
+      st_translate(gcenter, -halfX, -halfY)
+    )
   );
-
-  return st_intersection(bbox, geom);
 end
 $$ language plpgsql;