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vincentsaragovincentsarago
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update examples
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6 files changed

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‎data/functions/hexagon.sql‎

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

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

‎data/functions/squares.sql‎

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

‎demo/leaflet/index_3035.html‎

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

‎demo/leaflet/index_4326.html‎

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

‎docker-compose.yml‎

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

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