geo_ops.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

	PG_RETURN_BOOL(FPgt(box1->low.x, box2->high.x));
}

/*		box_overright	-		is the left edge of box1 at or right of
 *								the left edge of box2?
 *
 *		This is "greater than or equal" for time ranges, when time ranges
 *		are stored as rectangles.
 */
Datum
box_overright(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPge(box1->low.x, box2->low.x));
}

/*		box_below		-		is box1 strictly below box2?
 */
Datum
box_below(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPlt(box1->high.y, box2->low.y));
}

/*		box_overbelow	-		is the upper edge of box1 at or below
 *								the upper edge of box2?
 */
Datum
box_overbelow(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPle(box1->high.y, box2->high.y));
}

/*		box_above		-		is box1 strictly above box2?
 */
Datum
box_above(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPgt(box1->low.y, box2->high.y));
}

/*		box_overabove	-		is the lower edge of box1 at or above
 *								the lower edge of box2?
 */
Datum
box_overabove(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPge(box1->low.y, box2->low.y));
}

/*		box_contained	-		is box1 contained by box2?
 */
Datum
box_contained(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPle(box1->high.x, box2->high.x) &&
				   FPge(box1->low.x, box2->low.x) &&
				   FPle(box1->high.y, box2->high.y) &&
				   FPge(box1->low.y, box2->low.y));
}

/*		box_contain		-		does box1 contain box2?
 */
Datum
box_contain(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPge(box1->high.x, box2->high.x) &&
				   FPle(box1->low.x, box2->low.x) &&
				   FPge(box1->high.y, box2->high.y) &&
				   FPle(box1->low.y, box2->low.y));
}


/*		box_positionop	-
 *				is box1 entirely {above,below} box2?
 *
 * box_below_eq and box_above_eq are obsolete versions that (probably
 * erroneously) accept the equal-boundaries case.  Since these are not
 * in sync with the box_left and box_right code, they are deprecated and
 * not supported in the PG 8.1 rtree operator class extension.
 */
Datum
box_below_eq(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPle(box1->high.y, box2->low.y));
}

Datum
box_above_eq(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPge(box1->low.y, box2->high.y));
}


/*		box_relop		-		is area(box1) relop area(box2), within
 *								our accuracy constraint?
 */
Datum
box_lt(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPlt(box_ar(box1), box_ar(box2)));
}

Datum
box_gt(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPgt(box_ar(box1), box_ar(box2)));
}

Datum
box_eq(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPeq(box_ar(box1), box_ar(box2)));
}

Datum
box_le(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPle(box_ar(box1), box_ar(box2)));
}

Datum
box_ge(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);

	PG_RETURN_BOOL(FPge(box_ar(box1), box_ar(box2)));
}


/*----------------------------------------------------------
 *	"Arithmetic" operators on boxes.
 *---------------------------------------------------------*/

/*		box_area		-		returns the area of the box.
 */
Datum
box_area(PG_FUNCTION_ARGS)
{
	BOX		   *box = PG_GETARG_BOX_P(0);

	PG_RETURN_FLOAT8(box_ar(box));
}


/*		box_width		-		returns the width of the box
 *								  (horizontal magnitude).
 */
Datum
box_width(PG_FUNCTION_ARGS)
{
	BOX		   *box = PG_GETARG_BOX_P(0);

	PG_RETURN_FLOAT8(box->high.x - box->low.x);
}


/*		box_height		-		returns the height of the box
 *								  (vertical magnitude).
 */
Datum
box_height(PG_FUNCTION_ARGS)
{
	BOX		   *box = PG_GETARG_BOX_P(0);

	PG_RETURN_FLOAT8(box->high.y - box->low.y);
}


/*		box_distance	-		returns the distance between the
 *								  center points of two boxes.
 */
Datum
box_distance(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);
	Point		a,
				b;

	box_cn(&a, box1);
	box_cn(&b, box2);

	PG_RETURN_FLOAT8(HYPOT(a.x - b.x, a.y - b.y));
}


/*		box_center		-		returns the center point of the box.
 */
Datum
box_center(PG_FUNCTION_ARGS)
{
	BOX		   *box = PG_GETARG_BOX_P(0);
	Point	   *result = (Point *) palloc(sizeof(Point));

	box_cn(result, box);

	PG_RETURN_POINT_P(result);
}


/*		box_ar	-		returns the area of the box.
 */
static double
box_ar(BOX *box)
{
	return box_wd(box) * box_ht(box);
}


/*		box_cn	-		stores the centerpoint of the box into *center.
 */
static void
box_cn(Point *center, BOX *box)
{
	center->x = (box->high.x + box->low.x) / 2.0;
	center->y = (box->high.y + box->low.y) / 2.0;
}


/*		box_wd	-		returns the width (length) of the box
 *								  (horizontal magnitude).
 */
static double
box_wd(BOX *box)
{
	return box->high.x - box->low.x;
}


/*		box_ht	-		returns the height of the box
 *								  (vertical magnitude).
 */
static double
box_ht(BOX *box)
{
	return box->high.y - box->low.y;
}


/*----------------------------------------------------------
 *	Funky operations.
 *---------------------------------------------------------*/

/*		box_intersect	-
 *				returns the overlapping portion of two boxes,
 *				  or NULL if they do not intersect.
 */
Datum
box_intersect(PG_FUNCTION_ARGS)
{
	BOX		   *box1 = PG_GETARG_BOX_P(0);
	BOX		   *box2 = PG_GETARG_BOX_P(1);
	BOX		   *result;

	if (!box_ov(box1, box2))
		PG_RETURN_NULL();

	result = (BOX *) palloc(sizeof(BOX));

	result->high.x = Min(box1->high.x, box2->high.x);
	result->low.x = Max(box1->low.x, box2->low.x);
	result->high.y = Min(box1->high.y, box2->high.y);
	result->low.y = Max(box1->low.y, box2->low.y);

	PG_RETURN_BOX_P(result);
}


/*		box_diagonal	-
 *				returns a line segment which happens to be the
 *				  positive-slope diagonal of "box".
 */
Datum
box_diagonal(PG_FUNCTION_ARGS)
{
	BOX		   *box = PG_GETARG_BOX_P(0);
	LSEG	   *result = (LSEG *) palloc(sizeof(LSEG));

	statlseg_construct(result, &box->high, &box->low);

	PG_RETURN_LSEG_P(result);
}

/***********************************************************************
 **
 **		Routines for 2D lines.
 **				Lines are not intended to be used as ADTs per se,
 **				but their ops are useful tools for other ADT ops.  Thus,
 **				there are few relops.
 **
 ***********************************************************************/

Datum
line_in(PG_FUNCTION_ARGS)
{
#ifdef ENABLE_LINE_TYPE
	char	   *str = PG_GETARG_CSTRING(0);
#endif
	LINE	   *line;

#ifdef ENABLE_LINE_TYPE
	/* when fixed, modify "not implemented", catalog/pg_type.h and SGML */
	LSEG		lseg;
	int			isopen;
	char	   *s;

	if ((!path_decode(TRUE, 2, str, &isopen, &s, &(lseg.p[0])))
		|| (*s != '\0'))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
				 errmsg("invalid input syntax for type line: \"%s\"", str)));

	line = (LINE *) palloc(sizeof(LINE));
	line_construct_pts(line, &lseg.p[0], &lseg.p[1]);
#else
	ereport(ERROR,
			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
			 errmsg("type \"line\" not yet implemented")));

	line = NULL;
#endif

	PG_RETURN_LINE_P(line);
}


Datum
line_out(PG_FUNCTION_ARGS)
{
#ifdef ENABLE_LINE_TYPE
	LINE	   *line = PG_GETARG_LINE_P(0);
#endif
	char	   *result;

#ifdef ENABLE_LINE_TYPE
	/* when fixed, modify "not implemented", catalog/pg_type.h and SGML */
	LSEG		lseg;

	if (FPzero(line->B))
	{							/* vertical */
		/* use "x = C" */
		result->A = -1;
		result->B = 0;
		result->C = pt1->x;
#ifdef GEODEBUG
		printf("line_out- line is vertical\n");
#endif
#ifdef NOT_USED
		result->m = DBL_MAX;
#endif

	}
	else if (FPzero(line->A))
	{							/* horizontal */
		/* use "x = C" */
		result->A = 0;
		result->B = -1;
		result->C = pt1->y;
#ifdef GEODEBUG
		printf("line_out- line is horizontal\n");
#endif
#ifdef NOT_USED
		result->m = 0.0;
#endif

	}
	else
	{
	}

	if (FPzero(line->A))		/* horizontal? */
	{
	}
	else if (FPzero(line->B))	/* vertical? */
	{
	}
	else
	{
	}

	return path_encode(TRUE, 2, (Point *) &(ls->p[0]));
#else
	ereport(ERROR,
			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
			 errmsg("type \"line\" not yet implemented")));
	result = NULL;
#endif

	PG_RETURN_CSTRING(result);
}

/*
 *		line_recv			- converts external binary format to line
 */
Datum
line_recv(PG_FUNCTION_ARGS)
{
	ereport(ERROR,
			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
			 errmsg("type \"line\" not yet implemented")));
	return 0;
}

/*
 *		line_send			- converts line to binary format
 */
Datum
line_send(PG_FUNCTION_ARGS)
{
	ereport(ERROR,
			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
			 errmsg("type \"line\" not yet implemented")));
	return 0;
}


/*----------------------------------------------------------
 *	Conversion routines from one line formula to internal.
 *		Internal form:	Ax+By+C=0
 *---------------------------------------------------------*/

/* line_construct_pm()
 * point-slope
 */
static LINE *
line_construct_pm(Point *pt, double m)
{
	LINE	   *result = (LINE *) palloc(sizeof(LINE));

	/* use "mx - y + yinter = 0" */
	result->A = m;
	result->B = -1.0;
	if (m == DBL_MAX)
		result->C = pt->y;
	else
		result->C = pt->y - m * pt->x;

#ifdef NOT_USED
	result->m = m;
#endif

	return result;
}

/*
 * Fill already-allocated LINE struct from two points on the line
 */
static void
line_construct_pts(LINE *line, Point *pt1, Point *pt2)
{
	if (FPeq(pt1->x, pt2->x))
	{							/* vertical */
		/* use "x = C" */
		line->A = -1;
		line->B = 0;
		line->C = pt1->x;
#ifdef NOT_USED
		line->m = DBL_MAX;
#endif
#ifdef GEODEBUG
		printf("line_construct_pts- line is vertical\n");
#endif
	}
	else if (FPeq(pt1->y, pt2->y))
	{							/* horizontal */
		/* use "y = C" */
		line->A = 0;
		line->B = -1;
		line->C = pt1->y;
#ifdef NOT_USED
		line->m = 0.0;
#endif
#ifdef GEODEBUG
		printf("line_construct_pts- line is horizontal\n");
#endif
	}
	else
	{
		/* use "mx - y + yinter = 0" */
		line->A = (pt2->y - pt1->y) / (pt2->x - pt1->x);
		line->B = -1.0;
		line->C = pt1->y - line->A * pt1->x;
#ifdef NOT_USED
		line->m = line->A;
#endif
#ifdef GEODEBUG
		printf("line_construct_pts- line is neither vertical nor horizontal (diffs x=%.*g, y=%.*g\n",
			   DBL_DIG, (pt2->x - pt1->x), DBL_DIG, (pt2->y - pt1->y));
#endif
	}
}

/* line_construct_pp()
 * two points
 */
Datum
line_construct_pp(PG_FUNCTION_ARGS)
{
	Point	   *pt1 = PG_GETARG_POINT_P(0);
	Point	   *pt2 = PG_GETARG_POINT_P(1);
	LINE	   *result = (LINE *) palloc(sizeof(LINE));

	line_construct_pts(result, pt1, pt2);
	PG_RETURN_LINE_P(result);
}


/*----------------------------------------------------------
 *	Relative position routines.
 *---------------------------------------------------------*/

Datum
line_intersect(PG_FUNCTION_ARGS)
{
	LINE	   *l1 = PG_GETARG_LINE_P(0);
	LINE	   *l2 = PG_GETARG_LINE_P(1);

	PG_RETURN_BOOL(!DatumGetBool(DirectFunctionCall2(line_parallel,
													 LinePGetDatum(l1),
													 LinePGetDatum(l2))));
}

Datum
line_parallel(PG_FUNCTION_ARGS)
{
	LINE	   *l1 = PG_GETARG_LINE_P(0);
	LINE	   *l2 = PG_GETARG_LINE_P(1);

#ifdef NOT_USED
	PG_RETURN_BOOL(FPeq(l1->m, l2->m));
#endif
	if (FPzero(l1->B))
		PG_RETURN_BOOL(FPzero(l2->B));

	PG_RETURN_BOOL(FPeq(l2->A, l1->A * (l2->B / l1->B)));
}

Datum
line_perp(PG_FUNCTION_ARGS)
{
	LINE	   *l1 = PG_GETARG_LINE_P(0);
	LINE	   *l2 = PG_GETARG_LINE_P(1);

#ifdef NOT_USED
	if (l1->m)
		PG_RETURN_BOOL(FPeq(l2->m / l1->m, -1.0));
	else if (l2->m)
		PG_RETURN_BOOL(FPeq(l1->m / l2->m, -1.0));
#endif
	if (FPzero(l1->A))
		PG_RETURN_BOOL(FPzero(l2->B));
	else if (FPzero(l1->B))
		PG_RETURN_BOOL(FPzero(l2->A));

	PG_RETURN_BOOL(FPeq(((l1->A * l2->B) / (l1->B * l2->A)), -1.0));
}

Datum
line_vertical(PG_FUNCTION_ARGS)
{
	LINE	   *line = PG_GETARG_LINE_P(0);

	PG_RETURN_BOOL(FPzero(line->B));