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--- new:bits [2018/02/18 19:15] – korshun
+++ new:bits [2018/02/19 12:29] (current) – korshun
@@ Line 1: / Line 1: @@
 ====== Bit functions ======
+These functions are for bit math.
+===== Powers of two =====
+  * ''int npo2(int x)'' -- returns the next lowest power of 2 greater or equal to X.
+  * ''int bitlog2(int x)'' -- returns the index of the highest used bit, aka integer binary logarithm. Useful to convert flags like ''1<<8 = 256'' back into ''8''.
 ===== Working with bit arrays =====
@@ Line 5: / Line 12: @@
 These functions allow you to work with variables as if they were arrays of bits:
-  * ''bool getbit(int a, int i)'' -- returns bit ''a[i]''
+  * ''bool getbit(int a, int i)'' -- returns bit ''a[i]''.
-  * ''void setbit(int a, int i)'' -- performs ''a[i] = 1''
+  * ''int setbit(int a, int i)'' -- performs ''a[i] = 1'' and returns the result.
-  * ''void clrbit(int a, int i)'' -- performs ''a[i] = 0''
+  * ''int clrbit(int a, int i)'' -- performs ''a[i] = 0'' and returns the result.
-  * ''void tglbit(int a, int i)'' -- performs ''a[i] = !a[i]''
+  * ''int tglbit(int a, int i)'' -- performs ''a[i] = !a[i]'' and returns the result.
 ===== Unsetting bit flags =====

ACSUtils Wiki