PostgreSQL/PostGIS - Create a wedge of a buffer around a point, with optional inner radius

ST_PointBufferWedge.sql

/*
 * @params
 * pnt   - center POINT geometry
 * sdeg  - wedge sector start value; in degrees
 * edeg  - wedge sector end value; in degrees
 * irad  - radius around @pnt for the inner extend of the wedge; in meter
 * orad  - radius around @pnt for the outer extend of the wedge; in meter
 * qsegs - vertices per full quarter circle; at least two vertices will be created
 *
 * The function will calculate the angular difference in clockwise direction, from @sdeg to @edeg.
 * @irad defaults to 0 to get a wedge including the center POINT geometry (full wedge)
 */

CREATE OR REPLACE FUNCTION ST_PointBufferWedge(
    pnt   GEOMETRY(POINT),
    sdeg  FLOAT,
    edeg  FLOAT,
    orad  FLOAT,
    irad  FLOAT DEFAULT 0,
    qsegs INT   DEFAULT 8
) RETURNS GEOMETRY(POLYGON) AS
  $$
    DECLARE
      srid   INT;
      tdelta FLOAT;
      otvert INT;
      otstep FLOAT;
      itvert INT;
      itstep FLOAT;

      wedge  GEOMETRY(POINT)[];

    BEGIN
      srid   := ST_SRID($1);
  
      tdelta := CASE ($2 <= $3) WHEN TRUE THEN $3-$2 ELSE 360.0-$2+$3 END;
      otvert := GREATEST($6 * (FLOOR(tdelta)/90), 2);
      otstep := tdelta/otvert;
      itvert := CASE irad > 0 WHEN TRUE THEN GREATEST((otvert * ($5/$4))::INT, $6/2) ELSE 1 END;
      itstep := COALESCE(NULLIF(tdelta/itvert, tdelta), 0);
  
      FOR n IN 0..itvert
        LOOP
          wedge := wedge || ST_Project($1::GEOGRAPHY, $5, RADIANS(MOD($3::NUMERIC-(n*itstep)::NUMERIC, 360.0::NUMERIC)))::GEOMETRY;
        END LOOP
      ;

      FOR n IN 0..otvert
        LOOP
          wedge := wedge || ST_Project($1::GEOGRAPHY, $4, RADIANS(MOD($2::NUMERIC+(n*otstep)::NUMERIC, 360.0::NUMERIC)))::GEOMETRY;
        END LOOP
      ;

      wedge := wedge || wedge[1];
      
      RETURN ST_MakePolygon(ST_SetSRID(ST_MakeLine(wedge), srid));
    END;
  $$
LANGUAGE 'plpgsql';