update examples

data/functions/hexagon.sql

@@ -0,0 +1,140 @@
+-- Custom "hexagon" layer
+-- Adapted from https://github.com/CrunchyData/pg_tileserv
+--
+--
+-- Given an input ZXY tile coordinate, output a set of hexagons
+-- (and hexagon coordinates) in web mercator that cover that tile
+CREATE OR REPLACE FUNCTION tilehexagons(
+    bounds geometry,
+    step integer,
+    epsg integer,
+    OUT geom geometry(Polygon, 3857), OUT i integer, OUT j integer)
+RETURNS SETOF record AS $$
+DECLARE
+    maxbounds geometry := ST_TileEnvelope(0, 0, 0);
+    edge float8;
+BEGIN
+    edge := (ST_XMax(bounds) - ST_XMin(bounds)) / pow(2, step);
+    FOR geom, i, j IN
+    SELECT ST_SetSRID(hexagon(h.i, h.j, edge), epsg), h.i, h.j
+    FROM hexagoncoordinates(bounds, edge) h
+    LOOP
+        IF maxbounds ~ geom AND bounds && geom THEN
+            RETURN NEXT;
+        END IF;
+    END LOOP;
+END;
+$$
+LANGUAGE 'plpgsql'
+IMMUTABLE
+STRICT
+PARALLEL SAFE;
+
+-- Given coordinates in the hexagon tiling that has this
+-- edge size, return the built-out hexagon
+CREATE OR REPLACE FUNCTION hexagon(
+    i integer,
+    j integer,
+    edge float8
+)
+RETURNS geometry AS $$
+DECLARE
+    h float8 := edge*cos(pi()/6.0);
+    cx float8 := 1.5*i*edge;
+    cy float8 := h*(2*j+abs(i%2));
+BEGIN
+RETURN ST_MakePolygon(ST_MakeLine(ARRAY[
+            ST_MakePoint(cx - 1.0*edge, cy + 0),
+            ST_MakePoint(cx - 0.5*edge, cy + -1*h),
+            ST_MakePoint(cx + 0.5*edge, cy + -1*h),
+            ST_MakePoint(cx + 1.0*edge, cy + 0),
+            ST_MakePoint(cx + 0.5*edge, cy + h),
+            ST_MakePoint(cx - 0.5*edge, cy + h),
+            ST_MakePoint(cx - 1.0*edge, cy + 0)
+        ]));
+END;
+$$
+LANGUAGE 'plpgsql'
+IMMUTABLE
+STRICT
+PARALLEL SAFE;
+
+-- Given a square bounds, find all the hexagonal cells
+-- of a hex tiling (determined by edge size)
+-- that might cover that square (slightly over-determined)
+CREATE OR REPLACE FUNCTION hexagoncoordinates(
+    bounds geometry,
+    edge float8,
+    OUT i integer,
+    OUT j integer
+)
+RETURNS SETOF record AS $$
+DECLARE
+    h float8 := edge*cos(pi()/6);
+    mini integer := floor(st_xmin(bounds) / (1.5*edge));
+    minj integer := floor(st_ymin(bounds) / (2*h));
+    maxi integer := ceil(st_xmax(bounds) / (1.5*edge));
+    maxj integer := ceil(st_ymax(bounds) / (2*h));
+BEGIN
+    FOR i, j IN
+    SELECT a, b
+    FROM generate_series(mini, maxi) a,
+         generate_series(minj, maxj) b
+    LOOP
+        RETURN NEXT;
+    END LOOP;
+END;
+$$
+LANGUAGE 'plpgsql'
+IMMUTABLE
+STRICT
+PARALLEL SAFE;
+
+-- Given an input tile, generate the covering hexagons Step parameter determines
+-- how many hexagons to generate per tile.
+CREATE OR REPLACE FUNCTION hexagon(
+    -- mandatory parameters
+    xmin float,
+    ymin float,
+    xmax float,
+    ymax float,
+    epsg integer,
+    -- additional parameters
+    query_params json
+)
+RETURNS bytea AS $$
+DECLARE
+    result bytea;
+    step integer;
+    bounds geometry;
+BEGIN
+    -- Find the bbox bounds
+    bounds := ST_MakeEnvelope(xmin, ymin, xmax, ymax, epsg);
+
+    step := coalesce((query_params ->> 'step')::int, 4);
+
+    WITH
+    rows AS (
+        -- All the hexes that interact with this tile
+        SELECT h.i, h.j, h.geom
+        FROM TileHexagons(bounds, step, epsg) h
+    ),
+    mvt AS (
+        -- Usual tile processing, ST_AsMVTGeom simplifies, quantizes,
+        -- and clips to tile boundary
+        SELECT ST_AsMVTGeom(rows.geom, bounds) AS geom, rows.i, rows.j
+        FROM rows
+    )
+    -- Generate MVT encoding of final input record
+    SELECT ST_AsMVT(mvt, 'default')
+    INTO result
+    FROM mvt;
+
+    RETURN result;
+END;
+$$
+LANGUAGE 'plpgsql'
+STABLE
+STRICT
+PARALLEL SAFE;
+

data/functions/landsat_poly_centroid.sql

@@ -0,0 +1,50 @@
+CREATE OR REPLACE FUNCTION landsat_poly_centroid(
+    -- mandatory parameters
+    xmin float,
+    ymin float,
+    xmax float,
+    ymax float,
+    epsg integer,
+    -- additional parameters
+    query_params json
+)
+RETURNS bytea
+AS $$
+DECLARE
+    bounds geometry;
+    tablename text;
+    result bytea;
+BEGIN
+    WITH
+    -- Create bbox enveloppe in given EPSG
+    bounds AS (
+        SELECT ST_MakeEnvelope(xmin, ymin, xmax, ymax, epsg) AS geom
+    ),
+    selected_geom AS (
+        SELECT t.*
+        FROM public.landsat_wrs t, bounds
+        WHERE ST_Intersects(t.geom, ST_Transform(bounds.geom, 4326))
+    ),
+    mvtgeom AS (
+      SELECT
+        ST_AsMVTGeom(ST_Transform(ST_Centroid(t.geom), epsg), bounds.geom) AS geom, t.path, t.row
+        FROM selected_geom t, bounds
+      UNION
+      SELECT ST_AsMVTGeom(ST_Transform(t.geom, epsg), bounds.geom) AS geom, t.path, t.row
+        FROM selected_geom t, bounds
+    )
+    SELECT ST_AsMVT(mvtgeom.*, 'default')
+
+    -- Put the query result into the result variale.
+    INTO result FROM mvtgeom;
+
+    -- Return the answer
+    RETURN result;
+END;
+$$
+LANGUAGE 'plpgsql'
+IMMUTABLE -- Same inputs always give same outputs
+STRICT -- Null input gets null output
+PARALLEL SAFE;
+
+COMMENT ON FUNCTION landsat_poly_centroid IS 'Return Combined Polygon/Centroid geometries from landsat table.';

data/functions/squares.sql

@@ -0,0 +1,65 @@
+CREATE OR REPLACE FUNCTION squares(
+    -- mandatory parameters
+    xmin float,
+    ymin float,
+    xmax float,
+    ymax float,
+    epsg integer,
+    -- additional parameters
+    query_params json
+)
+RETURNS bytea AS $$
+DECLARE
+    result bytea;
+    sq_width float;
+    bbox_xmin float;
+    bbox_ymin float;
+    bounds geometry;
+    depth integer;
+BEGIN
+    -- Find the bbox bounds
+    bounds := ST_MakeEnvelope(xmin, ymin, xmax, ymax, epsg);
+
+    -- Find the bottom corner of the bounds
+    bbox_xmin := ST_XMin(bounds);
+    bbox_ymin := ST_YMin(bounds);
+
+    -- We want bbox divided up into depth*depth squares per bbox,
+    -- so what is the width of a square?
+    depth := coalesce((query_params ->> 'depth')::int, 2);
+
+    sq_width := (ST_XMax(bounds) - ST_XMin(bounds)) / depth;
+
+    WITH mvtgeom AS (
+        SELECT
+            -- Fill in the bbox with all the squares
+            ST_AsMVTGeom(
+                ST_SetSRID(
+                    ST_MakeEnvelope(
+                        bbox_xmin + sq_width * (a - 1),
+                        bbox_ymin + sq_width * (b - 1),
+                        bbox_xmin + sq_width * a,
+                        bbox_ymin + sq_width * b
+                    ),
+                    epsg
+                ),
+                bounds
+            )
+
+        -- Drive the square generator with a two-dimensional
+        -- generate_series setup
+        FROM generate_series(1, depth) a, generate_series(1, depth) b
+    )
+    SELECT ST_AsMVT(mvtgeom.*, 'default')
+
+    -- Put the query result into the result variale.
+    INTO result FROM mvtgeom;
+
+    -- Return the answer
+    RETURN result;
+END;
+$$
+LANGUAGE 'plpgsql'
+IMMUTABLE -- Same inputs always give same outputs
+STRICT -- Null input gets null output
+PARALLEL SAFE;

demo/leaflet/index_3035.html

@@ -31,7 +31,7 @@
       }
       );
 
-      var mapboxUrl = "http://0.0.0.0:8081/tiles/EuropeanETRS89_LAEAQuad/public.countries/{z}/{x}/{y}";
+      var mapboxUrl = "http://127.0.0.1:8000/tiles/EuropeanETRS89_LAEAQuad/public.countries/{z}/{x}/{y}";
 
       var mapboxVectorTileOptions = {
         rendererFactory: L.canvas.tile,

demo/leaflet/index_4326.html

@@ -26,7 +26,7 @@
         continuousWorld: true,
       }).addTo(map)
 
-      var mapboxUrl = "http://0.0.0.0:8081/tiles/WGS1984Quad/public.countries/{z}/{x}/{y}.pbf";
+      var mapboxUrl = "http://127.0.0.1:8000/tiles/WGS1984Quad/public.countries/{z}/{x}/{y}";
 
       var mapboxVectorTileOptions = {
         rendererFactory: L.canvas.tile,

docker-compose.yml

@@ -37,3 +37,21 @@ services:
     command: postgres -N 500
     volumes:
       - ./.pgdata:/var/lib/postgresql/data
+
+  # pg_tileserv:
+  #   image: pramsey/pg_tileserv:latest
+  #   environment:
+  #     - DATABASE_URL=postgresql://username:password@database:5432/postgis
+  #   ports:
+  #     - "7800:7800"
+  #   depends_on:
+  #   - database
+
+  # martin:
+  #   image: maplibre/martin
+  #   environment:
+  #     - DATABASE_URL=postgresql://username:password@database:5432/postgis
+  #   ports:
+  #     - "3000:3000"
+  #   depends_on:
+  #   - database