Build sector function postgis

sector_build.sql

-- Radian
create or replace function misc_normalizeRadians(rad double precision)
returns double precision
as $$
    SELECT r-floor(r/pi())*(2*pi()) FROM (SELECT (floor(rad/(2*pi()))*-(2*pi())+rad) as r) as t;
$$ LANGUAGE sql immutable;

-- Heading by angle
create or replace function misc_rotateHeadingByAngle(heading double precision,angle double precision)
returns double precision
as $$
    select misc_normalizeRadians($1-$2);
$$ LANGUAGE sql immutable;

-- build clone
create or replace function util_buildCone(origin geometry,bearing double precision,angle double precision,sides double precision)
returns geometry
as $$
BEGIN
    IF ST_GeometryType($1)!='ST_Point' THEN
         RAISE EXCEPTION 'Function only well defined for points, got: %',ST_GeometryType($1);
    END IF;
    IF abs($3)>=pi() THEN
         RAISE EXCEPTION 'Cones can''t have interior angle greater or equal to half a rotation, got: %',$3;
    END IF;
    RETURN (select ST_MakePolygon(ST_MakeLine(ARRAY[$1,a,b,$1]))
            from
                 util_translateTowardsBearing($1,misc_rotateHeadingByAngle($2,$3/2),$4) as a,
                 util_translateTowardsBearing($1,misc_rotateHeadingByAngle($2,-$3/2),$4) as b);
END
$$ language plpgsql immutable;

-- Build sector
create or replace function buildSector(origin geometry,bearing double precision,angle double precision,sides double precision)
returns geometry
as $$
BEGIN
    IF ST_GeometryType($1)!='ST_Point' THEN
        RAISE EXCEPTION 'Function only well defined for points, got: %',ST_GeometryType($1);
    END IF;
    IF abs($3)>(2*pi()) THEN
        RAISE EXCEPTION 'Cones can''t have a sector greater than the whole circle, got : %',$3;
    END IF;
    IF abs($3)=(2*pi()) THEN
        RETURN (select ST_Buffer($1,$4,50));
    END IF;
    IF abs($3)>(pi()/2) THEN
        RETURN (select  ST_Union(a,ST_Snap(b,a,$4/10000))
                from    buildSector($1,misc_rotateHeadingByAngle($2,$3/4),$3/2,$4) as a,
                        buildSector($1,misc_rotateHeadingByAngle($2,-$3/4),$3/2,$4) as b);
    END IF;
    RETURN (select ST_Intersection(ST_Buffer($1,$4,50),util_buildCone($1,$2,$3,$4*2)));
END
$$ language plpgsql immutable;