common: add some more bit utilities

2 files changed, 8 insertions, 6 deletions

diff --git a/src/common.h b/src/common.h
index f9d9f77..b1c3273 100644
--- a/src/common.h
+++ b/src/common.h
@@ -54,9 +54,11 @@
 
 #define SYSCALL(call) while (((call) == -1) && (errno == EINTR))
 
-#define GETBIT(m, x) ((m>>(x))&1U)
-#define SETBIT(m, x) (m|=(1U<<(x)))
-#define CLEARBIT(m, x) (m&=~(1U<<(x)))
+#define BITMASK(x) (1U << (x))
+#define BITONES(x) (BITMASK(x) - 1U)
+#define GETBIT(m, x) (((m) >> (x)) & 1U)
+#define SETBIT(m, x) (m |= BITMASK(x))
+#define CLEARBIT(m, x) (m &= ~BITMASK(x))
 
 ////////////////////////////////////////////////////////
 
diff --git a/src/gestures.c b/src/gestures.c
index 8ba32f3..89dad1a 100644
--- a/src/gestures.c
+++ b/src/gestures.c
@@ -51,11 +51,11 @@ void extract_gestures(struct Gestures *gs, struct MTouch* mt)
                 if (nsf == 3)
                         SETBIT(gs->type, GS_HSCROLL);
         }
-        if (mt->ns.button == (1U << MT_BUTTON_LEFT)) {
+        if (mt->ns.button == BITMASK(MT_BUTTON_LEFT)) {
                 if (nsf == 2)
-                        mt->ns.button = (1U << MT_BUTTON_RIGHT);
+                        mt->ns.button = BITMASK(MT_BUTTON_RIGHT);
                 if (nsf == 3)
-                        mt->ns.button = (1U << MT_BUTTON_MIDDLE);
+                        mt->ns.button = BITMASK(MT_BUTTON_MIDDLE);
         }
         for (i = 0; i < DIM_BUTTON; i++) {
                 if (GETBIT(mt->ns.button, i) != GETBIT(mt->os.button, i)) {