-- **************************
--
-- spherical point functions
--
-- **************************

CREATE FUNCTION pg_sphere_version()
   RETURNS CSTRING
   AS 'MODULE_PATHNAME', 'pg_sphere_version'
   LANGUAGE 'c';

CREATE FUNCTION spoint(FLOAT8, FLOAT8)
   RETURNS spoint
   AS 'MODULE_PATHNAME', 'spherepoint_from_long_lat'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

CREATE FUNCTION set_sphere_output_precision(INT4)
   RETURNS CSTRING
   AS 'MODULE_PATHNAME', 'set_sphere_output_precision'
   LANGUAGE 'c';

CREATE FUNCTION set_sphere_output(CSTRING)
   RETURNS CSTRING
   AS 'MODULE_PATHNAME', 'set_sphere_output'
   LANGUAGE 'c';

COMMENT ON FUNCTION spoint(FLOAT8, FLOAT8) IS
  'returns a spherical point from longitude (arg1), latitude (arg2)';

CREATE FUNCTION long(spoint)
   RETURNS FLOAT8
   AS 'MODULE_PATHNAME', 'spherepoint_long'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION long(spoint) IS
  'longitude of spherical point';

CREATE FUNCTION lat(spoint)
   RETURNS FLOAT8
   AS 'MODULE_PATHNAME', 'spherepoint_lat'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION lat(spoint) IS
  'latitude of spherical point';

CREATE FUNCTION x(spoint)
   RETURNS FLOAT8
   AS 'MODULE_PATHNAME', 'spherepoint_x'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION x(spoint) IS
  'cartesian x value of spherical point';


CREATE FUNCTION y(spoint)
   RETURNS FLOAT8
   AS 'MODULE_PATHNAME', 'spherepoint_y'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION y(spoint) IS
  'cartesian y value of spherical point';

CREATE FUNCTION xyz(spoint)
   RETURNS FLOAT8[]
   AS 'MODULE_PATHNAME', 'spherepoint_xyz'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION xyz(spoint) IS
  'cartesian values of spherical point';


CREATE FUNCTION z(spoint)
   RETURNS FLOAT8
   AS 'MODULE_PATHNAME', 'spherepoint_z'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION z(spoint) IS
  'cartesian z value of spherical point';


-- ***************************
--
-- spherical point operators
--
-- ***************************

--
-- equal
--

CREATE FUNCTION spoint_equal(spoint, spoint)
   RETURNS BOOL
   AS 'MODULE_PATHNAME', 'spherepoint_equal'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION spoint_equal(spoint, spoint) IS
  'returns true, if spherical points are equal';

CREATE OPERATOR  = (
   LEFTARG    = spoint,
   RIGHTARG   = spoint,
   COMMUTATOR = =,
   NEGATOR    = <>,
   PROCEDURE  = spoint_equal,
   RESTRICT   = contsel,
   JOIN       = contjoinsel
);

COMMENT ON OPERATOR = (spoint, spoint) IS
  'true, if spherical points are equal';

--
-- not equal
--

CREATE FUNCTION spoint_equal_neg (spoint, spoint)
   RETURNS BOOL
   AS 'SELECT NOT spoint_equal($1,$2);'
   LANGUAGE 'sql'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION spoint_equal_neg (spoint, spoint) IS
  'returns true, if spherical points are not equal';


CREATE OPERATOR  <> (
   LEFTARG    = spoint,
   RIGHTARG   = spoint,
   COMMUTATOR = <>,
   NEGATOR    = =,
   PROCEDURE  = spoint_equal_neg,
   RESTRICT   = contsel,
   JOIN       = contjoinsel
);

COMMENT ON OPERATOR <> (spoint, spoint) IS
  'true, if spherical points are not equal';

--
-- distance between points
--

CREATE FUNCTION dist(spoint, spoint)
   RETURNS FLOAT8
   AS 'MODULE_PATHNAME', 'spherepoint_distance'
   LANGUAGE 'c'
   IMMUTABLE STRICT;

COMMENT ON FUNCTION dist(spoint, spoint) IS
  'distance between spherical points';

CREATE OPERATOR  <-> (
   LEFTARG    = spoint,
   RIGHTARG   = spoint,
   COMMUTATOR = '<->',
   PROCEDURE  = dist
);

COMMENT ON OPERATOR <-> (spoint, spoint) IS
  'distance between spherical points';