[GRASS-SVN] r52048 - grass/trunk/lib/bitmap

[svn_grass at osgeo.org]

Author: mmetz
Date: 2012-06-12 06:20:39 -0700 (Tue, 12 Jun 2012)
New Revision: 52048

Modified:
   grass/trunk/lib/bitmap/sparse.c
Log:
bitmap lib: use bit manipulation

Modified: grass/trunk/lib/bitmap/sparse.c
===================================================================
--- grass/trunk/lib/bitmap/sparse.c	2012-06-12 12:42:53 UTC (rev 52047)
+++ grass/trunk/lib/bitmap/sparse.c	2012-06-12 13:20:39 UTC (rev 52048)
@@ -23,8 +23,8 @@
 #include <grass/bitmap.h>
 
 
-#define BM_col_to_byte(x)  ((x)/8)
-#define BM_col_to_bit(x)   ((x)%8)
+#define BM_col_to_byte(x)  ((x) >> 3)  /* x / 8 */
+#define BM_col_to_bit(x)   ((x) & 7)   /* x % 8 */
 
 static int depth;