(svn r11538) -Codechange: Rewrite GetNthSetBit in a more uncontroversial way and add its documentation
--- a/src/town_gui.cpp Wed Nov 28 15:42:52 2007 +0000
+++ b/src/town_gui.cpp Wed Nov 28 21:59:06 2007 +0000
@@ -109,15 +109,22 @@
return buttons;
}
+/**
+ * Get the position of the Nth set bit.
+ *
+ * If there is no Nth bit set return -1
+ *
+ * @param bits The value to search in
+ * @param n The Nth set bit from which we want to know the position
+ * @return The position of the Nth set bit
+ */
static int GetNthSetBit(uint32 bits, int n)
{
- int i = 0;
-
if (n >= 0) {
- do {
- if (bits & 1 && --n < 0) return i;
- i++;
- } while (bits >>= 1);
+ for (uint i = 0; bits != 0; bits >>= 1, i++) {
+ if (bits & 1) n--;
+ if (n < 0) return i;
+ }
}
return -1;
}