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authorFrank Warmerdam <warmerdam@pobox.com>2000-11-18 19:24:19 +0000
committerFrank Warmerdam <warmerdam@pobox.com>2000-11-18 19:24:19 +0000
commitd503ded5a03e626b093b21f2e6adb842560a4260 (patch)
tree8d721f24230bdf7a7bc3fbf0b20818ac4aacc445
parentc86123e30f1ef6d77e609ffe6eb7312ebc95c0d1 (diff)
downloadPROJ-d503ded5a03e626b093b21f2e6adb842560a4260.tar.gz
PROJ-d503ded5a03e626b093b21f2e6adb842560a4260.zip
applied adjlon fix from Craig Bruce
git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@881 4e78687f-474d-0410-85f9-8d5e500ac6b2
-rw-r--r--ChangeLog6
-rw-r--r--src/adjlon.c21
2 files changed, 17 insertions, 10 deletions
diff --git a/ChangeLog b/ChangeLog
index 0f7602c9..f8249a8f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2000-11-18 Frank Warmerdam <warmerda@cs46980-c>
+
+ * Patch from Craig Bruce to adjlon.c to avoid wrong results,
+ and near-hangs when adjusting very large numbers.
+ http://bugzilla.remotesensing.org/show_bug.cgi?id=27
+
2000-09-22 Frank Warmerdam <warmerda@cs46980-c>
* Fixed src/Makefile.am install-exec-local target, and added
diff --git a/src/adjlon.c b/src/adjlon.c
index 3de12a16..04f04400 100644
--- a/src/adjlon.c
+++ b/src/adjlon.c
@@ -3,14 +3,15 @@
static const char SCCSID[]="@(#)adjlon.c 4.3 93/06/12 GIE REL";
#endif
#include <math.h>
-/* note: PI adjusted high
-** approx. true val: 3.14159265358979323844
-*/
-#define SPI 3.14159265359
-#define TWOPI 6.2831853071795864769
- double
-adjlon (double lon) {
- while ( fabs(lon) > SPI )
- lon += lon < 0. ? TWOPI : -TWOPI;
- return( lon );
+
+#define SPI 3.14159265359
+#define TWOPI 6.2831853071795864769
+#define ONEPI 3.14159265358979323846
+
+double adjlon (double lon) {
+ if (fabs(lon) <= SPI) return( lon );
+ lon += ONEPI; /* adjust to 0..2pi rad */
+ lon -= TWOPI * floor(lon / TWOPI); /* remove integral # of 'revolutions'*/
+ lon -= ONEPI; /* adjust back to -pi..pi rad */
+ return( lon );
}