added invpow (arbitrary logarithm, finds a power that the base number would need...

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@2807 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/mathlib.h b/mathlib.h
index 29b9c6cfd594143664ca8d856c0f9d052e7b30a3..002c3f132b5e9eda844144250d40ffeff2037f30 100644 (file)
--- a/mathlib.h
+++ b/mathlib.h
@@ -51,6 +51,8 @@ extern vec3_t vec3_origin;
 
 #define lhrandom(MIN,MAX) ((rand() & 32767) * (((MAX)-(MIN)) * (1.0f / 32767.0f)) + (MIN))
 
+#define invpow(base,number) (log(number) / log(base))
+
 #define DEG2RAD(a) ((a) * ((float) M_PI / 180.0f))
 #define RAD2DEG(a) ((a) * (180.0f / (float) M_PI))
 #define ANGLEMOD(a) (((int) ((a) * (65536.0f / 360.0f)) & 65535) * (360.0f / 65536.0f))