Replace imprecise value of PI with a better one, and tweak circle_poly

in hopes of reducing platform-to-platform variations in its results.
This will cause the geometry regression test to start failing on some
platforms.  I plan to update the test later today.

diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index ddad122585167e4313159d720196ab25bd85e231..513b6c1321e60995380adb7c2ab49442640daf98 100644 (file)
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.67 2002/11/08 17:37:52 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.68 2002/11/08 18:32:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,10 +22,12 @@
 #include "utils/builtins.h"
 #include "utils/geo_decls.h"
 
-#ifndef PI
-#define PI 3.1415926536
+#ifndef M_PI
+/* from my RH5.2 gcc math.h file - thomas 2000-04-03 */
+#define M_PI 3.14159265358979323846
 #endif
 
+
 /*
  * Internal routines
  */
@@ -4365,7 +4367,7 @@ circle_center(PG_FUNCTION_ARGS)
 static double
 circle_ar(CIRCLE *circle)
 {
-       return PI * (circle->radius * circle->radius);
+       return M_PI * (circle->radius * circle->radius);
 }
 
 
@@ -4438,6 +4440,7 @@ circle_poly(PG_FUNCTION_ARGS)
                                size;
        int                     i;
        double          angle;
+       double          anglestep;
 
        if (FPzero(circle->radius) || (npts < 2))
                elog(ERROR, "Unable to convert circle to polygon");
@@ -4455,9 +4458,11 @@ circle_poly(PG_FUNCTION_ARGS)
        poly->size = size;
        poly->npts = npts;
 
+       anglestep = (2.0 * M_PI) / npts;
+
        for (i = 0; i < npts; i++)
        {
-               angle = i * (2 * PI / npts);
+               angle = i * anglestep;
                poly->p[i].x = circle->center.x - (circle->radius * cos(angle));
                poly->p[i].y = circle->center.y + (circle->radius * sin(angle));
        }