1-- gnomonic projection and its inverse 2 3CREATE FUNCTION gnomonic_proj(spoint, spoint) 4RETURNS point 5AS 'MODULE_PATHNAME' 6LANGUAGE C IMMUTABLE STRICT; 7 8COMMENT ON FUNCTION gnomonic_proj(spoint, spoint) IS 9'gnomonic projection, the second argument is the tangential point'; 10 11CREATE FUNCTION gnomonic_inv(point, spoint) 12RETURNS spoint 13AS 'MODULE_PATHNAME' 14LANGUAGE C IMMUTABLE STRICT; 15 16COMMENT ON FUNCTION gnomonic_inv(point, spoint) IS 17'inverse of gnomonic projection, the second argument is the tangential point'; 18