From 3f52d1705a993d152556b51bb8880b2f47f8b951 Mon Sep 17 00:00:00 2001
From: "Thomas G. Lockhart" <lockhart@fourpalms.org>
Date: Tue, 3 Feb 1998 15:55:58 +0000
Subject: [PATCH] Define boolean functions for lseg <, <=, <>, >=, > Define
close_ls(), close_lseg(), lseg_length(). Write real code for close_sb(),
close_pb(), inter_sb(), inter_lb(). Repair lseg_perp() which determines if
two lsegs are perpendicular. Repair lseg_dt() distance between two lsegs.
Note: close_sl() is clearly broken but will repair later (calculating point
on lseg rather than point on line).
---
src/backend/utils/adt/geo_ops.c | 669 ++++++++++++++++++++++++--------
1 file changed, 505 insertions(+), 164 deletions(-)
diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index 0978970313c..c3845fdcc4f 100644
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.29 1998/01/07 18:46:47 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.30 1998/02/03 15:55:58 thomas Exp $
*
*-------------------------------------------------------------------------
*/
@@ -135,14 +135,14 @@ single_decode(char *str, float8 *x, char **s)
*s = cp;
return (TRUE);
-} /* single_decode() */
+} /* single_decode() */
static int
single_encode(float8 x, char *str)
{
sprintf(str, "%.*g", digits8, x);
return (TRUE);
-} /* single_encode() */
+} /* single_encode() */
static int
pair_decode(char *str, float8 *x, float8 *y, char **s)
@@ -267,7 +267,7 @@ path_decode(int opentype, int npts, char *str, int *isopen, char **ss, Point *p)
*ss = s;
return (TRUE);
-} /* path_decode() */
+} /* path_decode() */
static char *
path_encode(bool closed, int npts, Point *pt)
@@ -315,7 +315,7 @@ path_encode(bool closed, int npts, Point *pt)
*cp = '\0';
return (result);
-} /* path_encode() */
+} /* path_encode() */
/*-------------------------------------------------------------
* pair_count - count the number of points
@@ -385,7 +385,7 @@ box_in(char *str)
}
return (box);
-} /* box_in() */
+} /* box_in() */
/* box_out - convert a box to external form.
*/
@@ -396,7 +396,7 @@ box_out(BOX *box)
return (NULL);
return (path_encode(-1, 2, (Point *) &(box->high)));
-} /* box_out() */
+} /* box_out() */
/* box_construct - fill in a new box.
@@ -620,7 +620,7 @@ box_width(BOX *box)
*result = box->high.x - box->low.x;
return (result);
-} /* box_width() */
+} /* box_width() */
/* box_height - returns the height of the box
@@ -765,7 +765,6 @@ box_diagonal(BOX *box)
p2.x = box->low.x;
p2.y = box->low.y;
return (lseg_construct(&p1, &p2));
-
}
/***********************************************************************
@@ -792,10 +791,12 @@ line_construct_pm(Point *pt, double m)
result->B = -1.0;
result->C = pt->y - m * pt->x;
+#if FALSE
result->m = m;
+#endif
return (result);
-} /* line_construct_pm() */
+} /* line_construct_pm() */
static LINE * /* two points */
@@ -812,7 +813,9 @@ line_construct_pp(Point *pt1, Point *pt2)
#ifdef GEODEBUG
printf("line_construct_pp- line is vertical\n");
#endif
+#if FALSE
result->m = DBL_MAX;
+#endif
}
else if (FPeq(pt1->y, pt2->y))
@@ -824,7 +827,9 @@ line_construct_pp(Point *pt1, Point *pt2)
#ifdef GEODEBUG
printf("line_construct_pp- line is horizontal\n");
#endif
+#if FALSE
result->m = 0.0;
+#endif
}
else
@@ -840,10 +845,12 @@ line_construct_pp(Point *pt1, Point *pt2)
printf("line_construct_pp- line is neither vertical nor horizontal (diffs x=%.*g, y=%.*g\n",
digits8, (pt2->x - pt1->x), digits8, (pt2->y - pt1->y));
#endif
+#if FALSE
result->m = result->A;
+#endif
}
return (result);
-} /* line_construct_pp() */
+} /* line_construct_pp() */
/*----------------------------------------------------------
@@ -868,7 +875,7 @@ line_parallel(LINE *l1, LINE *l2)
}
return (FPeq(l2->A, l1->A * (l2->B / l1->B)));
-} /* line_parallel() */
+} /* line_parallel() */
#ifdef NOT_USED
bool
@@ -890,7 +897,7 @@ line_perp(LINE *l1, LINE *l2)
}
return (FPeq(((l1->A * l2->B) / (l1->B * l2->A)), -1.0));
-} /* line_perp() */
+} /* line_perp() */
#endif
@@ -901,7 +908,7 @@ line_vertical(LINE *line)
return (FPeq(line->A, -1.0) && FPzero(line->B));
#endif
return (FPzero(line->B));
-} /* line_vertical() */
+} /* line_vertical() */
static bool
line_horizontal(LINE *line)
@@ -910,7 +917,7 @@ line_horizontal(LINE *line)
return (FPzero(line->m));
#endif
return (FPzero(line->A));
-} /* line_horizontal() */
+} /* line_horizontal() */
#ifdef NOT_USED
bool
@@ -1021,7 +1028,7 @@ line_interpt(LINE *l1, LINE *l2)
printf("line_interpt- lines intersect at (%.*g,%.*g)\n", digits8, x, digits8, y);
#endif
return (result);
-} /* line_interpt() */
+} /* line_interpt() */
/***********************************************************************
@@ -1087,7 +1094,7 @@ path_in(char *str)
path->closed = (!isopen);
return (path);
-} /* path_in() */
+} /* path_in() */
char *
@@ -1097,7 +1104,7 @@ path_out(PATH *path)
return NULL;
return (path_encode(path->closed, path->npts, (Point *) &(path->p[0])));
-} /* path_out() */
+} /* path_out() */
/*----------------------------------------------------------
@@ -1150,7 +1157,7 @@ path_isclosed(PATH *path)
return FALSE;
return (path->closed);
-} /* path_isclosed() */
+} /* path_isclosed() */
bool
path_isopen(PATH *path)
@@ -1159,7 +1166,7 @@ path_isopen(PATH *path)
return FALSE;
return (!path->closed);
-} /* path_isopen() */
+} /* path_isopen() */
int4
@@ -1169,7 +1176,7 @@ path_npoints(PATH *path)
return 0;
return (path->npts);
-} /* path_npoints() */
+} /* path_npoints() */
PATH *
path_close(PATH *path)
@@ -1183,7 +1190,7 @@ path_close(PATH *path)
result->closed = TRUE;
return (result);
-} /* path_close() */
+} /* path_close() */
PATH *
@@ -1198,7 +1205,7 @@ path_open(PATH *path)
result->closed = FALSE;
return (result);
-} /* path_open() */
+} /* path_open() */
PATH *
@@ -1212,7 +1219,7 @@ path_copy(PATH *path)
memmove((char *) result, (char *) path, size);
return (result);
-} /* path_copy() */
+} /* path_copy() */
/* path_inter -
@@ -1249,7 +1256,7 @@ path_inter(PATH *p1, PATH *p2)
b2.low.y = Min(p2->p[i].y, b2.low.y);
}
if (!box_overlap(&b1, &b2))
- return (0);
+ return (FALSE);
/* pairwise check lseg intersections */
for (i = 0; i < p1->npts - 1; i++)
@@ -1259,16 +1266,18 @@ path_inter(PATH *p1, PATH *p2)
statlseg_construct(&seg1, &p1->p[i], &p1->p[i + 1]);
statlseg_construct(&seg2, &p2->p[j], &p2->p[j + 1]);
if (lseg_intersect(&seg1, &seg2))
- return (1);
+ return (TRUE);
}
}
/* if we dropped through, no two segs intersected */
- return (0);
-}
+ return (FALSE);
+} /* path_inter() */
-/* this essentially does a cartesian product of the lsegs in the
- two paths, and finds the min distance between any two lsegs */
+/* path_distance()
+ * This essentially does a cartesian product of the lsegs in the
+ * two paths, and finds the min distance between any two lsegs
+ */
double *
path_distance(PATH *p1, PATH *p2)
{
@@ -1305,7 +1314,7 @@ path_distance(PATH *p1, PATH *p2)
}
return (min);
-}
+} /* path_distance() */
/*----------------------------------------------------------
@@ -1325,7 +1334,7 @@ path_length(PATH *path)
*result += point_dt(&path->p[i], &path->p[i + 1]);
return (result);
-} /* path_length() */
+} /* path_length() */
#ifdef NOT_USED
@@ -1340,7 +1349,7 @@ path_ln(PATH *path)
result += point_dt(&path->p[i], &path->p[i + 1]);
return (result);
-} /* path_ln() */
+} /* path_ln() */
#endif
@@ -1378,7 +1387,7 @@ point_in(char *str)
point->y = y;
return (point);
-} /* point_in() */
+} /* point_in() */
char *
point_out(Point *pt)
@@ -1387,7 +1396,7 @@ point_out(Point *pt)
return (NULL);
return (path_encode(-1, 1, pt));
-} /* point_out() */
+} /* point_out() */
static Point *
@@ -1500,6 +1509,10 @@ point_distance(Point *pt1, Point *pt2)
double
point_dt(Point *pt1, Point *pt2)
{
+#ifdef GEODEBUG
+printf("point_dt- segment (%f,%f),(%f,%f) length is %f\n",
+ pt1->x, pt1->y, pt2->x, pt2->y, HYPOT(pt1->x - pt2->x, pt1->y - pt2->y));
+#endif
return (HYPOT(pt1->x - pt2->x, pt1->y - pt2->y));
}
@@ -1557,10 +1570,12 @@ lseg_in(char *str)
|| (*s != '\0'))
elog(ERROR, "Bad lseg external representation '%s'", str);
+#if FALSE
lseg->m = point_sl(&lseg->p[0], &lseg->p[1]);
+#endif
return (lseg);
-} /* lseg_in() */
+} /* lseg_in() */
char *
@@ -1570,7 +1585,7 @@ lseg_out(LSEG *ls)
return (NULL);
return (path_encode(FALSE, 2, (Point *) &(ls->p[0])));
-} /* lseg_out() */
+} /* lseg_out() */
/* lseg_construct -
@@ -1586,7 +1601,9 @@ lseg_construct(Point *pt1, Point *pt2)
result->p[1].x = pt2->x;
result->p[1].y = pt2->y;
+#if FALSE
result->m = point_sl(pt1, pt2);
+#endif
return (result);
}
@@ -1600,9 +1617,24 @@ statlseg_construct(LSEG *lseg, Point *pt1, Point *pt2)
lseg->p[1].x = pt2->x;
lseg->p[1].y = pt2->y;
+#if FALSE
lseg->m = point_sl(pt1, pt2);
+#endif
}
+double *
+lseg_length(LSEG *lseg)
+{
+ double *result;
+
+ if (!PointerIsValid(lseg))
+ return (NULL);
+
+ result = point_distance(&lseg->p[0], &lseg->p[1]);
+
+ return (result);
+} /* lseg_length() */
+
/*----------------------------------------------------------
* Relative position routines.
*---------------------------------------------------------*/
@@ -1639,8 +1671,17 @@ lseg_parallel(LSEG *l1, LSEG *l2)
#endif
return (FPeq(point_sl(&(l1->p[0]), &(l1->p[1])),
point_sl(&(l2->p[0]), &(l2->p[1]))));
-} /* lseg_parallel() */
+} /* lseg_parallel() */
+/* lseg_perp()
+ * Determine if two line segments are perpendicular.
+ *
+ * This code did not get the correct answer for
+ * '((0,0),(0,1))'::lseg ?-| '((0,0),(1,0))'::lseg
+ * So, modified it to check explicitly for slope of vertical line
+ * returned by point_sl() and the results seem better.
+ * - thomas 1998-01-31
+ */
bool
lseg_perp(LSEG *l1, LSEG *l2)
{
@@ -1650,12 +1691,16 @@ lseg_perp(LSEG *l1, LSEG *l2)
m1 = point_sl(&(l1->p[0]), &(l1->p[1]));
m2 = point_sl(&(l2->p[0]), &(l2->p[1]));
- if (!FPzero(m1))
- return (FPeq(m2 / m1, -1.0));
- else if (!FPzero(m2))
- return (FPeq(m1 / m2, -1.0));
- return (0); /* both 0.0 */
-} /* lseg_perp() */
+#ifdef GEODEBUG
+printf("lseg_perp- slopes are %g and %g\n", m1, m2);
+#endif
+ if (FPzero(m1))
+ return(FPeq(m2, DBL_MAX));
+ else if (FPzero(m2))
+ return(FPeq(m1, DBL_MAX));
+
+ return (FPeq(m1 / m2, -1.0));
+} /* lseg_perp() */
bool
lseg_vertical(LSEG *lseg)
@@ -1677,7 +1722,40 @@ lseg_eq(LSEG *l1, LSEG *l2)
FPeq(l1->p[1].y, l2->p[1].y) &&
FPeq(l1->p[0].x, l2->p[0].x) &&
FPeq(l1->p[1].y, l2->p[1].y));
-}
+} /* lseg_eq() */
+
+bool
+lseg_ne(LSEG *l1, LSEG *l2)
+{
+ return (!FPeq(l1->p[0].x, l2->p[0].x) ||
+ !FPeq(l1->p[1].y, l2->p[1].y) ||
+ !FPeq(l1->p[0].x, l2->p[0].x) ||
+ !FPeq(l1->p[1].y, l2->p[1].y));
+} /* lseg_ne() */
+
+bool
+lseg_lt(LSEG *l1, LSEG *l2)
+{
+ return (FPlt(point_dt(&l1->p[0], &l1->p[1]), point_dt(&l2->p[0], &l2->p[1])));
+} /* lseg_lt() */
+
+bool
+lseg_le(LSEG *l1, LSEG *l2)
+{
+ return (FPle(point_dt(&l1->p[0], &l1->p[1]), point_dt(&l2->p[0], &l2->p[1])));
+} /* lseg_le() */
+
+bool
+lseg_gt(LSEG *l1, LSEG *l2)
+{
+ return (FPgt(point_dt(&l1->p[0], &l1->p[1]), point_dt(&l2->p[0], &l2->p[1])));
+} /* lseg_gt() */
+
+bool
+lseg_ge(LSEG *l1, LSEG *l2)
+{
+ return (FPge(point_dt(&l1->p[0], &l1->p[1]), point_dt(&l2->p[0], &l2->p[1])));
+} /* lseg_ge() */
/*----------------------------------------------------------
@@ -1699,7 +1777,11 @@ lseg_distance(LSEG *l1, LSEG *l2)
return (result);
}
-/* distance between l1, l2 */
+/* lseg_dt()
+ * Distance between two line segments.
+ * Must check both sets of endpoints to ensure minimum distance is found.
+ * - thomas 1998-02-01
+ */
static double
lseg_dt(LSEG *l1, LSEG *l2)
{
@@ -1715,20 +1797,15 @@ lseg_dt(LSEG *l1, LSEG *l2)
d = dist_ps(&l1->p[1], l2);
result = Min(result, *d);
pfree(d);
-#if FALSE
-/* XXX Why are we checking distances from all endpoints to the other segment?
- * One set of endpoints should be sufficient - tgl 97/07/03
- */
d = dist_ps(&l2->p[0], l1);
result = Min(result, *d);
pfree(d);
d = dist_ps(&l2->p[1], l1);
result = Min(result, *d);
pfree(d);
-#endif
return (result);
-} /* lseg_dt() */
+} /* lseg_dt() */
Point *
@@ -1745,7 +1822,7 @@ lseg_center(LSEG *lseg)
result->y = (lseg->p[0].y - lseg->p[1].y) / 2;
return (result);
-} /* lseg_center() */
+} /* lseg_center() */
/* lseg_interpt -
@@ -1798,7 +1875,7 @@ lseg_interpt(LSEG *l1, LSEG *l2)
pfree(tmp2);
return (result);
-} /* lseg_interpt() */
+} /* lseg_interpt() */
/***********************************************************************
**
@@ -2081,7 +2158,7 @@ dist_cpoly(CIRCLE *circle, POLYGON *poly)
*result = 0;
return (result);
-} /* dist_cpoly() */
+} /* dist_cpoly() */
/*---------------------------------------------------------------------
@@ -2178,13 +2255,17 @@ close_pl(Point *pt, LINE *line)
tmp = line_construct_pm(pt, invm);
result = line_interpt(tmp, line);
return (result);
-} /* close_pl() */
+} /* close_pl() */
-/* close_ps -
- * Take the closest endpoint if the point is left, right,
- * above, or below the segment, otherwise find the intersection
- * point of the segment and its perpendicular through the point.
+/* close_ps()
+ * Closest point on line segment to specified point.
+ * Take the closest endpoint if the point is left, right,
+ * above, or below the segment, otherwise find the intersection
+ * point of the segment and its perpendicular through the point.
+ *
+ * Some tricky code here, relying on boolean expressions
+ * evaluating to only zero or one to use as an array index.
*/
Point *
close_ps(Point *pt, LSEG *lseg)
@@ -2206,47 +2287,149 @@ close_ps(Point *pt, LSEG *lseg)
result = point_copy(&lseg->p[!yh]);
else if (pt->y > lseg->p[yh].y)
result = point_copy(&lseg->p[yh]);
- if (result)
+ if (result != NULL)
return (result);
-#if FALSE
- if (FPeq(lseg->p[0].x, lseg->p[1].x)) /* vertical */
+
+ /* vertical segment? */
+ if (lseg_vertical(lseg))
+ {
+#ifdef GEODEBUG
+printf("close_ps- segment is vertical\n");
#endif
- if (lseg_vertical(lseg))
- {
- result->x = lseg->p[0].x;
- result->y = pt->y;
- return (result);
-#if FALSE
- }
- else if (FPzero(lseg->m))
- { /* horizontal */
+ result = palloc(sizeof(*result));
+ result->x = lseg->p[0].x;
+ result->y = pt->y;
+ return (result);
+ }
+ else if (lseg_horizontal(lseg))
+ {
+#ifdef GEODEBUG
+printf("close_ps- segment is horizontal\n");
#endif
- }
- else if (lseg_horizontal(lseg))
- {
- result->x = pt->x;
- result->y = lseg->p[0].y;
- return (result);
- }
+ result = palloc(sizeof(*result));
+ result->x = pt->x;
+ result->y = lseg->p[0].y;
+ return (result);
+ }
-#if FALSE
- invm = -1.0 / lseg->m;
-#endif
invm = -1.0 / point_sl(&(lseg->p[0]), &(lseg->p[1]));
tmp = line_construct_pm(pt, invm);
result = interpt_sl(lseg, tmp);
return (result);
-} /* close_ps() */
+} /* close_ps() */
+/* close_lseg()
+ * Closest point to l1 on l2.
+ */
+Point *
+close_lseg(LSEG *l1, LSEG *l2)
+{
+ Point *result = NULL;
+ Point point;
+ double dist;
+ double *d;
+
+ d = dist_ps(&l1->p[0], l2);
+ dist = *d;
+ memcpy(&point, &l1->p[0], sizeof(point));
+ pfree(d);
+
+ if (*(d = dist_ps(&l1->p[1], l2)) < dist)
+ {
+ dist = *d;
+ memcpy(&point, &l1->p[1], sizeof(point));
+ }
+ pfree(d);
+
+ if (*(d = dist_ps(&l2->p[0], l1)) < dist)
+ {
+ result = close_ps(&l2->p[0], l1);
+ memcpy(&point, result, sizeof(point));
+ pfree(result);
+ result = close_ps(&point, l2);
+ }
+ pfree(d);
+
+ if (*(d = dist_ps(&l2->p[1], l1)) < dist)
+ {
+ if (result != NULL) pfree(result);
+
+ result = close_ps(&l2->p[1], l1);
+ memcpy(&point, result, sizeof(point));
+ pfree(result);
+ result = close_ps(&point, l2);
+ }
+ pfree(d);
+
+ if (result == NULL)
+ {
+ result = palloc(sizeof(*result));
+ memcpy(result, &point, sizeof(*result));
+ }
+
+ return (result);
+} /* close_lseg() */
+
+/* close_pb()
+ * Closest point on or in box to specified point.
+ */
Point *
close_pb(Point *pt, BOX *box)
{
- /* think about this one for a while */
- elog(ERROR, "close_pb not implemented", NULL);
+ LSEG lseg,
+ seg;
+ Point point;
+ double dist,
+ *d;
- return (NULL);
-}
+ if (on_pb(pt, box))
+ return (pt);
+
+ /* pairwise check lseg distances */
+ point.x = box->low.x;
+ point.y = box->high.y;
+ statlseg_construct(&lseg, &box->low, &point);
+ dist = *(d = dist_ps(pt, &lseg));
+ pfree(d);
+
+ statlseg_construct(&seg, &box->high, &point);
+ if (*(d = dist_ps(pt, &seg)) < dist)
+ {
+ dist = *d;
+ memcpy(&lseg,&seg,sizeof(lseg));
+ }
+ pfree(d);
+
+ point.x = box->high.x;
+ point.y = box->low.y;
+ statlseg_construct(&seg, &box->low, &point);
+ if (*(d = dist_ps(pt, &seg)) < dist)
+ {
+ dist = *d;
+ memcpy(&lseg,&seg,sizeof(lseg));
+ }
+ pfree(d);
+
+ statlseg_construct(&seg, &box->high, &point);
+ if (*(d = dist_ps(pt, &seg)) < dist)
+ {
+ dist = *d;
+ memcpy(&lseg,&seg,sizeof(lseg));
+ }
+ pfree(d);
+
+ return (close_ps(pt, &lseg));
+} /* close_pb() */
+/* close_sl()
+ * Closest point on line to line segment.
+ *
+ * XXX THIS CODE IS WRONG
+ * The code is actually calculating the point on the line segment
+ * which is backwards from the routine naming convention.
+ * Copied code to new routine close_ls() but haven't fixed this one yet.
+ * - thomas 1998-01-31
+ */
Point *
close_sl(LSEG *lseg, LINE *line)
{
@@ -2257,6 +2440,7 @@ close_sl(LSEG *lseg, LINE *line)
result = interpt_sl(lseg, line);
if (result)
return (result);
+
d1 = dist_pl(&lseg->p[0], line);
d2 = dist_pl(&lseg->p[1], line);
if (d1 < d2)
@@ -2269,14 +2453,88 @@ close_sl(LSEG *lseg, LINE *line)
return (result);
}
+/* close_ls()
+ * Closest point on line segment to line.
+ */
+Point *
+close_ls(LINE *line, LSEG *lseg)
+{
+ Point *result;
+ double *d1,
+ *d2;
+
+ result = interpt_sl(lseg, line);
+ if (result)
+ return (result);
+
+ d1 = dist_pl(&lseg->p[0], line);
+ d2 = dist_pl(&lseg->p[1], line);
+ if (d1 < d2)
+ result = point_copy(&lseg->p[0]);
+ else
+ result = point_copy(&lseg->p[1]);
+
+ pfree(d1);
+ pfree(d2);
+ return (result);
+} /* close_ls() */
+
+/* close_sb()
+ * Closest point on or in box to line segment.
+ */
Point *
close_sb(LSEG *lseg, BOX *box)
{
- /* think about this one for a while */
- elog(ERROR, "close_sb not implemented", NULL);
+ Point *result;
+ Point *pt;
+ Point point;
- return (NULL);
-}
+ LSEG bseg,
+ seg;
+ double dist,
+ d;
+
+ /* segment intersects box? then just return closest point to center */
+ if (inter_sb(lseg, box))
+ {
+ pt = box_center(box);
+ result = close_ps(pt, lseg);
+ pfree(pt);
+ return (result);
+ }
+
+ /* pairwise check lseg distances */
+ point.x = box->low.x;
+ point.y = box->high.y;
+ statlseg_construct(&bseg, &box->low, &point);
+ dist = lseg_dt(lseg, &bseg);
+
+ statlseg_construct(&seg, &box->high, &point);
+ if ((d = lseg_dt(lseg, &seg)) < dist)
+ {
+ dist = d;
+ memcpy(&bseg, &seg, sizeof(bseg));
+ }
+
+ point.x = box->high.x;
+ point.y = box->low.y;
+ statlseg_construct(&seg, &box->low, &point);
+ if ((d = lseg_dt(lseg, &seg)) < dist)
+ {
+ dist = d;
+ memcpy(&bseg, &seg, sizeof(bseg));
+ }
+
+ statlseg_construct(&seg, &box->high, &point);
+ if ((d = lseg_dt(lseg, &seg)) < dist)
+ {
+ dist = d;
+ memcpy(&bseg, &seg, sizeof(bseg));
+ }
+
+ /* OK, we now have the closest line segment on the box boundary */
+ return (close_lseg(lseg, &bseg));
+} /* close_sb() */
Point *
close_lb(LINE *line, BOX *box)
@@ -2374,10 +2632,10 @@ on_ppath(Point *pt, PATH *path)
b = point_dt(pt, &path->p[i + 1]);
if (FPeq(a + b,
point_dt(&path->p[i], &path->p[i + 1])))
- return (1);
+ return (TRUE);
a = b;
}
- return (0);
+ return (FALSE);
}
return (point_inside(pt, path->npts, path->p));
@@ -2404,7 +2662,7 @@ on_ppath(Point *pt, PATH *path)
if (FPeq(yh, yl)) /* horizontal seg? */
if (FPge(pt->x, xl) && FPle(pt->x, xh) &&
FPeq(pt->y, yh))
- return (1); /* pt lies on seg */
+ return (TRUE); /* pt lies on seg */
else
continue; /* skip other hz segs */
if (FPlt(yh, pt->y) || /* pt is strictly below seg */
@@ -2420,7 +2678,7 @@ on_ppath(Point *pt, PATH *path)
&path->p[NEXT(i)]) +
path->p[i].x;
if (FPeq(x, pt->x)) /* pt lies on this seg */
- return (1);
+ return (TRUE);
/* does the seg actually cross the ray? */
@@ -2432,7 +2690,7 @@ on_ppath(Point *pt, PATH *path)
return (above == UNDEF || /* path is horizontal */
inter % 2); /* odd # of intersections */
#endif
-} /* on_ppath() */
+} /* on_ppath() */
bool
@@ -2442,7 +2700,7 @@ on_sl(LSEG *lseg, LINE *line)
return (FALSE);
return (on_pl(&lseg->p[0], line) && on_pl(&lseg->p[1], line));
-} /* on_sl() */
+} /* on_sl() */
bool
on_sb(LSEG *lseg, BOX *box)
@@ -2451,7 +2709,7 @@ on_sb(LSEG *lseg, BOX *box)
return (FALSE);
return (on_pb(&lseg->p[0], box) && on_pb(&lseg->p[1], box));
-} /* on_sb() */
+} /* on_sb() */
/*---------------------------------------------------------------------
* inter_
@@ -2470,25 +2728,108 @@ inter_sl(LSEG *lseg, LINE *line)
if (tmp)
{
pfree(tmp);
- return (1);
+ return (TRUE);
}
- return (0);
+ return (FALSE);
}
-/* XXX segment and box should be able to intersect; tgl - 97/01/09 */
-
+/* inter_sb()
+ * Do line segment and box intersect?
+ *
+ * Segment completely inside box counts as intersection.
+ * If you want only segments crossing box boundaries,
+ * try converting box to path first.
+ *
+ * Optimize for non-intersection by checking for box intersection first.
+ * - thomas 1998-01-30
+ */
bool
inter_sb(LSEG *lseg, BOX *box)
{
- return (0);
-}
+ BOX lbox;
+ LSEG bseg;
+ Point point;
+
+ if (!PointerIsValid(lseg) || !PointerIsValid(box))
+ return (FALSE);
+
+ lbox.low.x = Min(lseg->p[0].x, lseg->p[1].x);
+ lbox.low.y = Min(lseg->p[0].y, lseg->p[1].y);
+ lbox.high.x = Max(lseg->p[0].x, lseg->p[1].x);
+ lbox.high.y = Max(lseg->p[0].y, lseg->p[1].y);
+
+ /* nothing close to overlap? then not going to intersect */
+ if (!box_overlap(&lbox, box))
+ return (FALSE);
+
+ /* an endpoint of segment is inside box? then clearly intersects */
+ if (on_pb(&lseg->p[0], box) || on_pb(&lseg->p[1], box))
+ return (TRUE);
+
+ /* pairwise check lseg intersections */
+ point.x = box->low.x;
+ point.y = box->high.y;
+ statlseg_construct(&bseg, &box->low, &point);
+ if (lseg_intersect(&bseg, lseg))
+ return (TRUE);
-/* XXX line and box should be able to intersect; tgl - 97/01/09 */
+ statlseg_construct(&bseg, &box->high, &point);
+ if (lseg_intersect(&bseg, lseg))
+ return (TRUE);
+
+ point.x = box->high.x;
+ point.y = box->low.y;
+ statlseg_construct(&bseg, &box->low, &point);
+ if (lseg_intersect(&bseg, lseg))
+ return (TRUE);
+
+ statlseg_construct(&bseg, &box->high, &point);
+ if (lseg_intersect(&bseg, lseg))
+ return (TRUE);
+
+ /* if we dropped through, no two segs intersected */
+ return (FALSE);
+} /* inter_sb() */
+/* inter_lb()
+ * Do line and box intersect?
+ */
bool
inter_lb(LINE *line, BOX *box)
{
- return (0);
+ LSEG bseg;
+ Point p1,
+ p2;
+
+ if (!PointerIsValid(line) || !PointerIsValid(box))
+ return (FALSE);
+
+ /* pairwise check lseg intersections */
+ p1.x = box->low.x;
+ p1.y = box->low.y;
+ p2.x = box->low.x;
+ p2.y = box->high.y;
+ statlseg_construct(&bseg, &p1, &p2);
+ if (inter_sl(&bseg, line))
+ return (TRUE);
+ p1.x = box->high.x;
+ p1.y = box->high.y;
+ statlseg_construct(&bseg, &p1, &p2);
+ if (inter_sl(&bseg, line))
+ return (TRUE);
+ p2.x = box->high.x;
+ p2.y = box->low.y;
+ statlseg_construct(&bseg, &p1, &p2);
+ if (inter_sl(&bseg, line))
+ return (TRUE);
+ p1.x = box->low.x;
+ p1.y = box->low.y;
+ statlseg_construct(&bseg, &p1, &p2);
+ if (inter_sl(&bseg, line))
+ return (TRUE);
+
+ /* if we dropped through, no intersection */
+ return (FALSE);
}
/*------------------------------------------------------------------
@@ -2572,7 +2913,7 @@ poly_in(char *str)
make_bound_box(poly);
return (poly);
-} /* poly_in() */
+} /* poly_in() */
/*---------------------------------------------------------------
* poly_out - convert internal POLYGON representation to the
@@ -2586,7 +2927,7 @@ poly_out(POLYGON *poly)
return NULL;
return (path_encode(TRUE, poly->npts, &(poly->p[0])));
-} /* poly_out() */
+} /* poly_out() */
/*-------------------------------------------------------
@@ -2724,7 +3065,7 @@ poly_contain(POLYGON *polya, POLYGON *polyb)
polya->boundbox.low.x, polya->boundbox.low.y, polya->boundbox.high.x, polya->boundbox.high.y);
#endif
return (FALSE);
-} /* poly_contain() */
+} /* poly_contain() */
/*-----------------------------------------------------------------
@@ -2744,7 +3085,7 @@ bool
poly_contained(POLYGON *polya, POLYGON *polyb)
{
return (poly_contain(polyb, polya));
-} /* poly_contained() */
+} /* poly_contained() */
/* poly_contain_pt()
@@ -2764,7 +3105,7 @@ poly_contain_pt(POLYGON *poly, Point *p)
return (FALSE);
return (point_inside(p, poly->npts, &(poly->p[0])) != 0);
-} /* poly_contain_pt() */
+} /* poly_contain_pt() */
bool
pt_contained_poly(Point *p, POLYGON *poly)
@@ -2773,7 +3114,7 @@ pt_contained_poly(Point *p, POLYGON *poly)
return (FALSE);
return (poly_contain_pt(poly, p));
-} /* pt_contained_poly() */
+} /* pt_contained_poly() */
double *
@@ -2789,7 +3130,7 @@ poly_distance(POLYGON *polya, POLYGON *polyb)
*result = 0;
return (result);
-} /* poly_distance() */
+} /* poly_distance() */
/***********************************************************************
@@ -2805,7 +3146,7 @@ point(float8 *x, float8 *y)
return (NULL);
return (point_construct(*x, *y));
-} /* point() */
+} /* point() */
Point *
@@ -2822,7 +3163,7 @@ point_add(Point *p1, Point *p2)
result->y = (p1->y + p2->y);
return (result);
-} /* point_add() */
+} /* point_add() */
Point *
point_sub(Point *p1, Point *p2)
@@ -2838,7 +3179,7 @@ point_sub(Point *p1, Point *p2)
result->y = (p1->y - p2->y);
return (result);
-} /* point_sub() */
+} /* point_sub() */
Point *
point_mul(Point *p1, Point *p2)
@@ -2854,7 +3195,7 @@ point_mul(Point *p1, Point *p2)
result->y = (p1->x * p2->y) + (p1->y * p2->x);
return (result);
-} /* point_mul() */
+} /* point_mul() */
Point *
point_div(Point *p1, Point *p2)
@@ -2876,7 +3217,7 @@ point_div(Point *p1, Point *p2)
result->y = ((p2->x * p1->y) - (p2->y * p1->x)) / div;
return (result);
-} /* point_div() */
+} /* point_div() */
/***********************************************************************
@@ -2896,7 +3237,7 @@ box(Point *p1, Point *p2)
result = box_construct(p1->x, p2->x, p1->y, p2->y);
return (result);
-} /* box() */
+} /* box() */
BOX *
box_add(BOX *box, Point *p)
@@ -2910,7 +3251,7 @@ box_add(BOX *box, Point *p)
(box->high.y + p->y), (box->low.y + p->y));
return (result);
-} /* box_add() */
+} /* box_add() */
BOX *
box_sub(BOX *box, Point *p)
@@ -2924,7 +3265,7 @@ box_sub(BOX *box, Point *p)
(box->high.y - p->y), (box->low.y - p->y));
return (result);
-} /* box_sub() */
+} /* box_sub() */
BOX *
box_mul(BOX *box, Point *p)
@@ -2944,7 +3285,7 @@ box_mul(BOX *box, Point *p)
pfree(low);
return (result);
-} /* box_mul() */
+} /* box_mul() */
BOX *
box_div(BOX *box, Point *p)
@@ -2964,7 +3305,7 @@ box_div(BOX *box, Point *p)
pfree(low);
return (result);
-} /* box_div() */
+} /* box_div() */
/***********************************************************************
@@ -3016,7 +3357,7 @@ path_add(PATH *p1, PATH *p2)
}
return (result);
-} /* path_add() */
+} /* path_add() */
/* path_add_pt()
* Translation operator.
@@ -3039,7 +3380,7 @@ path_add_pt(PATH *path, Point *point)
}
return (result);
-} /* path_add_pt() */
+} /* path_add_pt() */
PATH *
path_sub_pt(PATH *path, Point *point)
@@ -3059,7 +3400,7 @@ path_sub_pt(PATH *path, Point *point)
}
return (result);
-} /* path_sub_pt() */
+} /* path_sub_pt() */
/* path_mul_pt()
@@ -3086,7 +3427,7 @@ path_mul_pt(PATH *path, Point *point)
}
return (result);
-} /* path_mul_pt() */
+} /* path_mul_pt() */
PATH *
path_div_pt(PATH *path, Point *point)
@@ -3109,7 +3450,7 @@ path_div_pt(PATH *path, Point *point)
}
return (result);
-} /* path_div_pt() */
+} /* path_div_pt() */
bool
@@ -3119,7 +3460,7 @@ path_contain_pt(PATH *path, Point *p)
return (FALSE);
return ((path->closed ? (point_inside(p, path->npts, &(path->p[0])) != 0) : FALSE));
-} /* path_contain_pt() */
+} /* path_contain_pt() */
bool
pt_contained_path(Point *p, PATH *path)
@@ -3128,7 +3469,7 @@ pt_contained_path(Point *p, PATH *path)
return (FALSE);
return (path_contain_pt(path, p));
-} /* pt_contained_path() */
+} /* pt_contained_path() */
Point *
@@ -3145,7 +3486,7 @@ path_center(PATH *path)
result = NULL;
return (result);
-} /* path_center() */
+} /* path_center() */
POLYGON *
path_poly(PATH *path)
@@ -3175,7 +3516,7 @@ path_poly(PATH *path)
make_bound_box(poly);
return (poly);
-} /* path_polygon() */
+} /* path_polygon() */
/* upgradepath()
@@ -3215,7 +3556,7 @@ upgradepath(PATH *path)
}
return (result);
-} /* upgradepath() */
+} /* upgradepath() */
bool
isoldpath(PATH *path)
@@ -3224,7 +3565,7 @@ isoldpath(PATH *path)
return (FALSE);
return (path->npts == (path->p[0].y + 1));
-} /* isoldpath() */
+} /* isoldpath() */
/***********************************************************************
@@ -3237,10 +3578,10 @@ int4
poly_npoints(POLYGON *poly)
{
if (!PointerIsValid(poly))
- return (0);
+ return (FALSE);
return (poly->npts);
-} /* poly_npoints() */
+} /* poly_npoints() */
Point *
@@ -3264,7 +3605,7 @@ poly_center(POLYGON *poly)
}
return (result);
-} /* poly_center() */
+} /* poly_center() */
BOX *
@@ -3278,7 +3619,7 @@ poly_box(POLYGON *poly)
box = box_copy(&poly->boundbox);
return (box);
-} /* poly_box() */
+} /* poly_box() */
/* box_poly()
@@ -3312,7 +3653,7 @@ box_poly(BOX *box)
box_fill(&poly->boundbox, box->high.x, box->low.x, box->high.y, box->low.y);
return (poly);
-} /* box_poly() */
+} /* box_poly() */
PATH *
@@ -3339,7 +3680,7 @@ poly_path(POLYGON *poly)
}
return (path);
-} /* poly_path() */
+} /* poly_path() */
/* upgradepoly()
@@ -3388,7 +3729,7 @@ upgradepoly(POLYGON *poly)
}
return (result);
-} /* upgradepoly() */
+} /* upgradepoly() */
/* revertpoly()
* Reverse effect of upgradepoly().
@@ -3434,7 +3775,7 @@ revertpoly(POLYGON *poly)
}
return (result);
-} /* revertpoly() */
+} /* revertpoly() */
/***********************************************************************
@@ -3513,7 +3854,7 @@ circle_in(char *str)
elog(ERROR, "Bad circle external representation '%s'", str);
return (circle);
-} /* circle_in() */
+} /* circle_in() */
/* circle_out - convert a circle to external form.
*/
@@ -3545,7 +3886,7 @@ circle_out(CIRCLE *circle)
*cp = '\0';
return (result);
-} /* circle_out() */
+} /* circle_out() */
/*----------------------------------------------------------
@@ -3645,37 +3986,37 @@ bool
circle_eq(CIRCLE *circle1, CIRCLE *circle2)
{
return (FPeq(circle_ar(circle1), circle_ar(circle2)));
-} /* circle_eq() */
+} /* circle_eq() */
bool
circle_ne(CIRCLE *circle1, CIRCLE *circle2)
{
return (!circle_eq(circle1, circle2));
-} /* circle_ne() */
+} /* circle_ne() */
bool
circle_lt(CIRCLE *circle1, CIRCLE *circle2)
{
return (FPlt(circle_ar(circle1), circle_ar(circle2)));
-} /* circle_lt() */
+} /* circle_lt() */
bool
circle_gt(CIRCLE *circle1, CIRCLE *circle2)
{
return (FPgt(circle_ar(circle1), circle_ar(circle2)));
-} /* circle_gt() */
+} /* circle_gt() */
bool
circle_le(CIRCLE *circle1, CIRCLE *circle2)
{
return (FPle(circle_ar(circle1), circle_ar(circle2)));
-} /* circle_le() */
+} /* circle_le() */
bool
circle_ge(CIRCLE *circle1, CIRCLE *circle2)
{
return (FPge(circle_ar(circle1), circle_ar(circle2)));
-} /* circle_ge() */
+} /* circle_ge() */
/*----------------------------------------------------------
@@ -3698,7 +4039,7 @@ circle_copy(CIRCLE *circle)
memmove((char *) result, (char *) circle, sizeof(CIRCLE));
return (result);
-} /* circle_copy() */
+} /* circle_copy() */
/* circle_add_pt()
@@ -3718,7 +4059,7 @@ circle_add_pt(CIRCLE *circle, Point *point)
result->center.y += point->y;
return (result);
-} /* circle_add_pt() */
+} /* circle_add_pt() */
CIRCLE *
circle_sub_pt(CIRCLE *circle, Point *point)
@@ -3734,7 +4075,7 @@ circle_sub_pt(CIRCLE *circle, Point *point)
result->center.y -= point->y;
return (result);
-} /* circle_sub_pt() */
+} /* circle_sub_pt() */
/* circle_mul_pt()
@@ -3758,7 +4099,7 @@ circle_mul_pt(CIRCLE *circle, Point *point)
result->radius *= HYPOT(point->x, point->y);
return (result);
-} /* circle_mul_pt() */
+} /* circle_mul_pt() */
CIRCLE *
circle_div_pt(CIRCLE *circle, Point *point)
@@ -3778,7 +4119,7 @@ circle_div_pt(CIRCLE *circle, Point *point)
result->radius /= HYPOT(point->x, point->y);
return (result);
-} /* circle_div_pt() */
+} /* circle_div_pt() */
/* circle_area - returns the area of the circle.
@@ -3838,7 +4179,7 @@ circle_distance(CIRCLE *circle1, CIRCLE *circle2)
*result = 0;
return (result);
-} /* circle_distance() */
+} /* circle_distance() */
bool
@@ -3855,14 +4196,14 @@ circle_contain_pt(CIRCLE *circle, Point *point)
pfree(d);
return (within);
-} /* circle_contain_pt() */
+} /* circle_contain_pt() */
bool
pt_contained_circle(Point *point, CIRCLE *circle)
{
return (circle_contain_pt(circle, point));
-} /* circle_contain_pt() */
+} /* circle_contain_pt() */
/* dist_pc - returns the distance between
@@ -3880,7 +4221,7 @@ dist_pc(Point *point, CIRCLE *circle)
*result = 0;
return (result);
-} /* dist_pc() */
+} /* dist_pc() */
/* circle_center - returns the center point of the circle.
@@ -3964,7 +4305,7 @@ circle_box(CIRCLE *circle)
box->low.y = circle->center.y - delta;
return (box);
-} /* circle_box() */
+} /* circle_box() */
/* box_circle()
* Convert a box to a circle.
@@ -3985,7 +4326,7 @@ box_circle(BOX *box)
circle->radius = point_dt(&circle->center, &box->high);
return (circle);
-} /* box_circle() */
+} /* box_circle() */
POLYGON *
@@ -4062,7 +4403,7 @@ poly_circle(POLYGON *poly)
elog(ERROR, "Unable to convert polygon to circle", NULL);
return (circle);
-} /* poly_circle() */
+} /* poly_circle() */
/***********************************************************************
@@ -4130,7 +4471,7 @@ point_inside(Point *p, int npts, Point plist[])
return 1;
}
return 0;
-} /* point_inside() */
+} /* point_inside() */
/* lseg_crossing()
@@ -4193,7 +4534,7 @@ lseg_crossing(double x, double y, double px, double py)
return (HIT_IT);
return (FPgt((sgn * z), 0) ? 0 : 2 * sgn);
}
-} /* lseg_crossing() */
+} /* lseg_crossing() */
static bool
--
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