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In geo_ops.c, represent infinite slope as Infinity, not DBL_MAX.

Browse Source 
Since we're assuming IEEE floats these days, there seems little
reason not to do this.  It has the advantage that when the slope is
computed as infinite due to the presence of Inf coordinates, we get
saner behavior than before from line_construct(), and thence also
in some dependent operations such as finding the closest point.

Also fix line_construct() to special-case slope zero.  The previous
coding got the right answer in most cases, but it could compute
C as NaN when the point has Inf coordinates.

Discussion: https://postgr.es/m/CAGf+fX70rWFOk5cd00uMfa__0yP+vtQg5ck7c2Onb-Yczp0URA@mail.gmail.com
This commit is contained in:
Tom Lane 2020-11-21 17:24:07 -05:00
parent 8597a48d01
commit 9fe649ea29
2 changed files with 140 additions and 133 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
src/backend/utils/adt/geo_ops.c
View File

@ -1055,13 +1055,20 @@ line_send(PG_FUNCTION_ARGS)
static inline void
line_construct(LINE *result, Point *pt, float8 m)
{
if (m == DBL_MAX)
if (isinf(m))
{
/* vertical - use "x = C" */
result->A = -1.0;
result->B = 0.0;
result->C = pt->x;
}
else if (m == 0)
{
/* horizontal - use "y = C" */
result->A = 0.0;
result->B = -1.0;
result->C = pt->y;
}
else
{
/* use "mx - y + yinter = 0" */
@ -1201,7 +1208,7 @@ line_sl(LINE *line)
if (FPzero(line->A))
return 0.0;
if (FPzero(line->B))
return DBL_MAX;
return get_float8_infinity();
return float8_div(line->A, -line->B);
}
@ -1213,7 +1220,7 @@ static inline float8
line_invsl(LINE *line)
{
if (FPzero(line->A))
return DBL_MAX;
return get_float8_infinity();
if (FPzero(line->B))
return 0.0;
return float8_div(line->B, line->A);
@ -1979,13 +1986,13 @@ point_slope(PG_FUNCTION_ARGS)
/*
* Return slope of two points
*
* Note that this function returns DBL_MAX when the points are the same.
* Note that this function returns Inf when the points are the same.
*/
static inline float8
point_sl(Point *pt1, Point *pt2)
{
if (FPeq(pt1->x, pt2->x))
return DBL_MAX;
return get_float8_infinity();
if (FPeq(pt1->y, pt2->y))
return 0.0;
return float8_div(float8_mi(pt1->y, pt2->y), float8_mi(pt1->x, pt2->x));
@ -2003,7 +2010,7 @@ point_invsl(Point *pt1, Point *pt2)
if (FPeq(pt1->x, pt2->x))
return 0.0;
if (FPeq(pt1->y, pt2->y))
return DBL_MAX;
return get_float8_infinity();
return float8_div(float8_mi(pt1->x, pt2->x), float8_mi(pt2->y, pt1->y));
}

74
src/test/regress/expected/geometry.out
View File

@ -112,19 +112,19 @@ SELECT '' AS one, p1.f1
-- Slope
SELECT p1.f1, p2.f1, slope(p1.f1, p2.f1) FROM POINT_TBL p1, POINT_TBL p2;
f1 | f1 | slope
-------------------+-------------------+--------------------
(0,0) | (0,0) | 1.79769313486e+308
-------------------+-------------------+----------------
(0,0) | (0,0) | Infinity
(0,0) | (-10,0) | 0
(0,0) | (-3,4) | -1.33333333333
(0,0) | (5.1,34.5) | 6.76470588235
(0,0) | (-5,-12) | 2.4
(0,0) | (1e-300,-1e-300) | 1.79769313486e+308
(0,0) | (1e-300,-1e-300) | Infinity
(0,0) | (1e+300,Infinity) | Infinity
(0,0) | (Infinity,1e+300) | 0
(0,0) | (NaN,NaN) | NaN
(0,0) | (10,10) | 1
(-10,0) | (0,0) | 0
(-10,0) | (-10,0) | 1.79769313486e+308
(-10,0) | (-10,0) | Infinity
(-10,0) | (-3,4) | 0.571428571429
(-10,0) | (5.1,34.5) | 2.28476821192
(-10,0) | (-5,-12) | -2.4
@ -135,7 +135,7 @@ SELECT p1.f1, p2.f1, slope(p1.f1, p2.f1) FROM POINT_TBL p1, POINT_TBL p2;
(-10,0) | (10,10) | 0.5
(-3,4) | (0,0) | -1.33333333333
(-3,4) | (-10,0) | 0.571428571429
(-3,4) | (-3,4) | 1.79769313486e+308
(-3,4) | (-3,4) | Infinity
(-3,4) | (5.1,34.5) | 3.76543209877
(-3,4) | (-5,-12) | 8
(-3,4) | (1e-300,-1e-300) | -1.33333333333
@ -146,7 +146,7 @@ SELECT p1.f1, p2.f1, slope(p1.f1, p2.f1) FROM POINT_TBL p1, POINT_TBL p2;
(5.1,34.5) | (0,0) | 6.76470588235
(5.1,34.5) | (-10,0) | 2.28476821192
(5.1,34.5) | (-3,4) | 3.76543209877
(5.1,34.5) | (5.1,34.5) | 1.79769313486e+308
(5.1,34.5) | (5.1,34.5) | Infinity
(5.1,34.5) | (-5,-12) | 4.60396039604
(5.1,34.5) | (1e-300,-1e-300) | 6.76470588235
(5.1,34.5) | (1e+300,Infinity) | Infinity
@ -157,18 +157,18 @@ SELECT p1.f1, p2.f1, slope(p1.f1, p2.f1) FROM POINT_TBL p1, POINT_TBL p2;
(-5,-12) | (-10,0) | -2.4
(-5,-12) | (-3,4) | 8
(-5,-12) | (5.1,34.5) | 4.60396039604
(-5,-12) | (-5,-12) | 1.79769313486e+308
(-5,-12) | (-5,-12) | Infinity
(-5,-12) | (1e-300,-1e-300) | 2.4
(-5,-12) | (1e+300,Infinity) | Infinity
(-5,-12) | (Infinity,1e+300) | 0
(-5,-12) | (NaN,NaN) | NaN
(-5,-12) | (10,10) | 1.46666666667
(1e-300,-1e-300) | (0,0) | 1.79769313486e+308
(1e-300,-1e-300) | (0,0) | Infinity
(1e-300,-1e-300) | (-10,0) | 0
(1e-300,-1e-300) | (-3,4) | -1.33333333333
(1e-300,-1e-300) | (5.1,34.5) | 6.76470588235
(1e-300,-1e-300) | (-5,-12) | 2.4
(1e-300,-1e-300) | (1e-300,-1e-300) | 1.79769313486e+308
(1e-300,-1e-300) | (1e-300,-1e-300) | Infinity
(1e-300,-1e-300) | (1e+300,Infinity) | Infinity
(1e-300,-1e-300) | (Infinity,1e+300) | 0
(1e-300,-1e-300) | (NaN,NaN) | NaN
@ -179,7 +179,7 @@ SELECT p1.f1, p2.f1, slope(p1.f1, p2.f1) FROM POINT_TBL p1, POINT_TBL p2;
(1e+300,Infinity) | (5.1,34.5) | Infinity
(1e+300,Infinity) | (-5,-12) | Infinity
(1e+300,Infinity) | (1e-300,-1e-300) | Infinity
(1e+300,Infinity) | (1e+300,Infinity) | 1.79769313486e+308
(1e+300,Infinity) | (1e+300,Infinity) | Infinity
(1e+300,Infinity) | (Infinity,1e+300) | NaN
(1e+300,Infinity) | (NaN,NaN) | NaN
(1e+300,Infinity) | (10,10) | Infinity
@ -190,7 +190,7 @@ SELECT p1.f1, p2.f1, slope(p1.f1, p2.f1) FROM POINT_TBL p1, POINT_TBL p2;
(Infinity,1e+300) | (-5,-12) | 0
(Infinity,1e+300) | (1e-300,-1e-300) | 0
(Infinity,1e+300) | (1e+300,Infinity) | NaN
(Infinity,1e+300) | (Infinity,1e+300) | 1.79769313486e+308
(Infinity,1e+300) | (Infinity,1e+300) | Infinity
(Infinity,1e+300) | (NaN,NaN) | NaN
(Infinity,1e+300) | (10,10) | 0
(NaN,NaN) | (0,0) | NaN
@ -212,7 +212,7 @@ SELECT p1.f1, p2.f1, slope(p1.f1, p2.f1) FROM POINT_TBL p1, POINT_TBL p2;
(10,10) | (1e+300,Infinity) | Infinity
(10,10) | (Infinity,1e+300) | 0
(10,10) | (NaN,NaN) | NaN
(10,10) | (10,10) | 1.79769313486e+308
(10,10) | (10,10) | Infinity
(100 rows)
-- Add point
@ -563,7 +563,7 @@ SELECT p.f1, l.s, p.f1 <-> l.s AS dist_pl, l.s <-> p.f1 AS dist_lp FROM POINT_TB
(1e+300,Infinity) | {0,-1,3} | Infinity | Infinity
(1e+300,Infinity) | {-1,0,3} | NaN | NaN
(Infinity,1e+300) | {0,-1,5} | NaN | NaN
(Infinity,1e+300) | {1,0,5} | NaN | NaN
(Infinity,1e+300) | {1,0,5} | Infinity | Infinity
(Infinity,1e+300) | {0,3,0} | NaN | NaN
(Infinity,1e+300) | {1,-1,0} | NaN | NaN
(Infinity,1e+300) | {-0.4,-1,-6} | NaN | NaN
@ -571,7 +571,7 @@ SELECT p.f1, l.s, p.f1 <-> l.s AS dist_pl, l.s <-> p.f1 AS dist_lp FROM POINT_TB
(Infinity,1e+300) | {3,NaN,5} | NaN | NaN
(Infinity,1e+300) | {NaN,NaN,NaN} | NaN | NaN
(Infinity,1e+300) | {0,-1,3} | NaN | NaN
(Infinity,1e+300) | {-1,0,3} | NaN | NaN
(Infinity,1e+300) | {-1,0,3} | Infinity | Infinity
(NaN,NaN) | {0,-1,5} | NaN | NaN
(NaN,NaN) | {1,0,5} | NaN | NaN
(NaN,NaN) | {0,3,0} | NaN | NaN
@ -917,7 +917,7 @@ SELECT p1.f1, p2.f1, line(p1.f1, p2.f1)
(0,0) | (-3,4) | {-1.33333333333,-1,0}
(0,0) | (5.1,34.5) | {6.76470588235,-1,0}
(0,0) | (-5,-12) | {2.4,-1,0}
(0,0) | (1e+300,Infinity) | {Infinity,-1,NaN}
(0,0) | (1e+300,Infinity) | {-1,0,0}
(0,0) | (Infinity,1e+300) | {0,-1,0}
(0,0) | (NaN,NaN) | {NaN,-1,NaN}
(0,0) | (10,10) | {1,-1,0}
@ -926,7 +926,7 @@ SELECT p1.f1, p2.f1, line(p1.f1, p2.f1)
(-10,0) | (5.1,34.5) | {2.28476821192,-1,22.8476821192}
(-10,0) | (-5,-12) | {-2.4,-1,-24}
(-10,0) | (1e-300,-1e-300) | {0,-1,0}
(-10,0) | (1e+300,Infinity) | {Infinity,-1,Infinity}
(-10,0) | (1e+300,Infinity) | {-1,0,-10}
(-10,0) | (Infinity,1e+300) | {0,-1,0}
(-10,0) | (NaN,NaN) | {NaN,-1,NaN}
(-10,0) | (10,10) | {0.5,-1,5}
@ -935,7 +935,7 @@ SELECT p1.f1, p2.f1, line(p1.f1, p2.f1)
(-3,4) | (5.1,34.5) | {3.76543209877,-1,15.2962962963}
(-3,4) | (-5,-12) | {8,-1,28}
(-3,4) | (1e-300,-1e-300) | {-1.33333333333,-1,0}
(-3,4) | (1e+300,Infinity) | {Infinity,-1,Infinity}
(-3,4) | (1e+300,Infinity) | {-1,0,-3}
(-3,4) | (Infinity,1e+300) | {0,-1,4}
(-3,4) | (NaN,NaN) | {NaN,-1,NaN}
(-3,4) | (10,10) | {0.461538461538,-1,5.38461538462}
@ -944,7 +944,7 @@ SELECT p1.f1, p2.f1, line(p1.f1, p2.f1)
(5.1,34.5) | (-3,4) | {3.76543209877,-1,15.2962962963}
(5.1,34.5) | (-5,-12) | {4.60396039604,-1,11.0198019802}
(5.1,34.5) | (1e-300,-1e-300) | {6.76470588235,-1,0}
(5.1,34.5) | (1e+300,Infinity) | {Infinity,-1,-Infinity}
(5.1,34.5) | (1e+300,Infinity) | {-1,0,5.1}
(5.1,34.5) | (Infinity,1e+300) | {0,-1,34.5}
(5.1,34.5) | (NaN,NaN) | {NaN,-1,NaN}
(5.1,34.5) | (10,10) | {-5,-1,60}
@ -953,7 +953,7 @@ SELECT p1.f1, p2.f1, line(p1.f1, p2.f1)
(-5,-12) | (-3,4) | {8,-1,28}
(-5,-12) | (5.1,34.5) | {4.60396039604,-1,11.0198019802}
(-5,-12) | (1e-300,-1e-300) | {2.4,-1,0}
(-5,-12) | (1e+300,Infinity) | {Infinity,-1,Infinity}
(-5,-12) | (1e+300,Infinity) | {-1,0,-5}
(-5,-12) | (Infinity,1e+300) | {0,-1,-12}
(-5,-12) | (NaN,NaN) | {NaN,-1,NaN}
(-5,-12) | (10,10) | {1.46666666667,-1,-4.66666666667}
@ -961,28 +961,28 @@ SELECT p1.f1, p2.f1, line(p1.f1, p2.f1)
(1e-300,-1e-300) | (-3,4) | {-1.33333333333,-1,3.33333333333e-301}
(1e-300,-1e-300) | (5.1,34.5) | {6.76470588235,-1,-7.76470588235e-300}
(1e-300,-1e-300) | (-5,-12) | {2.4,-1,-3.4e-300}
(1e-300,-1e-300) | (1e+300,Infinity) | {Infinity,-1,-Infinity}
(1e-300,-1e-300) | (1e+300,Infinity) | {-1,0,1e-300}
(1e-300,-1e-300) | (Infinity,1e+300) | {0,-1,-1e-300}
(1e-300,-1e-300) | (NaN,NaN) | {NaN,-1,NaN}
(1e-300,-1e-300) | (10,10) | {1,-1,-2e-300}
(1e+300,Infinity) | (0,0) | {Infinity,-1,NaN}
(1e+300,Infinity) | (-10,0) | {Infinity,-1,NaN}
(1e+300,Infinity) | (-3,4) | {Infinity,-1,NaN}
(1e+300,Infinity) | (5.1,34.5) | {Infinity,-1,NaN}
(1e+300,Infinity) | (-5,-12) | {Infinity,-1,NaN}
(1e+300,Infinity) | (1e-300,-1e-300) | {Infinity,-1,NaN}
(1e+300,Infinity) | (0,0) | {-1,0,1e+300}
(1e+300,Infinity) | (-10,0) | {-1,0,1e+300}
(1e+300,Infinity) | (-3,4) | {-1,0,1e+300}
(1e+300,Infinity) | (5.1,34.5) | {-1,0,1e+300}
(1e+300,Infinity) | (-5,-12) | {-1,0,1e+300}
(1e+300,Infinity) | (1e-300,-1e-300) | {-1,0,1e+300}
(1e+300,Infinity) | (Infinity,1e+300) | {NaN,-1,NaN}
(1e+300,Infinity) | (NaN,NaN) | {NaN,-1,NaN}
(1e+300,Infinity) | (10,10) | {Infinity,-1,NaN}
(Infinity,1e+300) | (0,0) | {0,-1,NaN}
(Infinity,1e+300) | (-10,0) | {0,-1,NaN}
(Infinity,1e+300) | (-3,4) | {0,-1,NaN}
(Infinity,1e+300) | (5.1,34.5) | {0,-1,NaN}
(Infinity,1e+300) | (-5,-12) | {0,-1,NaN}
(Infinity,1e+300) | (1e-300,-1e-300) | {0,-1,NaN}
(1e+300,Infinity) | (10,10) | {-1,0,1e+300}
(Infinity,1e+300) | (0,0) | {0,-1,1e+300}
(Infinity,1e+300) | (-10,0) | {0,-1,1e+300}
(Infinity,1e+300) | (-3,4) | {0,-1,1e+300}
(Infinity,1e+300) | (5.1,34.5) | {0,-1,1e+300}
(Infinity,1e+300) | (-5,-12) | {0,-1,1e+300}
(Infinity,1e+300) | (1e-300,-1e-300) | {0,-1,1e+300}
(Infinity,1e+300) | (1e+300,Infinity) | {NaN,-1,NaN}
(Infinity,1e+300) | (NaN,NaN) | {NaN,-1,NaN}
(Infinity,1e+300) | (10,10) | {0,-1,NaN}
(Infinity,1e+300) | (10,10) | {0,-1,1e+300}
(NaN,NaN) | (0,0) | {NaN,-1,NaN}
(NaN,NaN) | (-10,0) | {NaN,-1,NaN}
(NaN,NaN) | (-3,4) | {NaN,-1,NaN}
@ -998,7 +998,7 @@ SELECT p1.f1, p2.f1, line(p1.f1, p2.f1)
(10,10) | (5.1,34.5) | {-5,-1,60}
(10,10) | (-5,-12) | {1.46666666667,-1,-4.66666666667}
(10,10) | (1e-300,-1e-300) | {1,-1,0}
(10,10) | (1e+300,Infinity) | {Infinity,-1,-Infinity}
(10,10) | (1e+300,Infinity) | {-1,0,10}
(10,10) | (Infinity,1e+300) | {0,-1,10}
(10,10) | (NaN,NaN) | {NaN,-1,NaN}
(88 rows)
@ -1078,7 +1078,7 @@ SELECT p.f1, l.s, p.f1 ## l.s FROM POINT_TBL p, LINE_TBL l;
(1e+300,Infinity) | {0,-1,3} | (1e+300,3)
(1e+300,Infinity) | {-1,0,3} |
(Infinity,1e+300) | {0,-1,5} |
(Infinity,1e+300) | {1,0,5} |
(Infinity,1e+300) | {1,0,5} | (-5,1e+300)
(Infinity,1e+300) | {0,3,0} |
(Infinity,1e+300) | {1,-1,0} |
(Infinity,1e+300) | {-0.4,-1,-6} |
@ -1086,7 +1086,7 @@ SELECT p.f1, l.s, p.f1 ## l.s FROM POINT_TBL p, LINE_TBL l;
(Infinity,1e+300) | {3,NaN,5} |
(Infinity,1e+300) | {NaN,NaN,NaN} |
(Infinity,1e+300) | {0,-1,3} |
(Infinity,1e+300) | {-1,0,3} |
(Infinity,1e+300) | {-1,0,3} | (3,1e+300)
(NaN,NaN) | {0,-1,5} |
(NaN,NaN) | {1,0,5} |
(NaN,NaN) | {0,3,0} |