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author | Jared Adams <jaxad0127@gmail.com> | 2009-04-14 16:44:03 -0600 |
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committer | Jared Adams <jaxad0127@gmail.com> | 2009-04-14 16:46:03 -0600 |
commit | dfd6bc3c91c7bd508b5bde820366784bd980a677 (patch) | |
tree | df44a1950dd589cad9eb08345fec5ab2457adba2 /src/utils/fastsqrt.h | |
parent | 87d906c4f3529e7ce8f836876292efbfbe765990 (diff) | |
download | mana-client-dfd6bc3c91c7bd508b5bde820366784bd980a677.tar.gz mana-client-dfd6bc3c91c7bd508b5bde820366784bd980a677.tar.bz2 mana-client-dfd6bc3c91c7bd508b5bde820366784bd980a677.tar.xz mana-client-dfd6bc3c91c7bd508b5bde820366784bd980a677.zip |
Start a MathUtils file
It has fast(inv)sqrt and weightedAverage.
Also cleanup the last ocmmit a bit.
Diffstat (limited to 'src/utils/fastsqrt.h')
-rw-r--r-- | src/utils/fastsqrt.h | 24 |
1 files changed, 0 insertions, 24 deletions
diff --git a/src/utils/fastsqrt.h b/src/utils/fastsqrt.h deleted file mode 100644 index 78768149..00000000 --- a/src/utils/fastsqrt.h +++ /dev/null @@ -1,24 +0,0 @@ -/* A very fast function to calculate the approximate inverse square root of a - * floating point value and a helper function that uses it for getting the - * normal squareroot. For an explanation of the inverse squareroot function - * read: - * http://www.math.purdue.edu/~clomont/Math/Papers/2003/InvSqrt.pdf - * - * Unfortunately the original creator of this function seems to be unknown. - */ - -float fastInvSqrt(float x) -{ - union { int i; float x; } tmp; - float xhalf = 0.5f * x; - tmp.x = x; - tmp.i = 0x5f375a86 - (tmp.i >> 1); - x = tmp.x; - x = x * (1.5f - xhalf * x * x); - return x; -} - -float fastSqrt(float x) -{ - return 1.0f / fastInvSqrt(x); -} |