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align btQuadWord on 16byte boundary

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slightly improved friction model
This commit is contained in:
ejcoumans
2007-09-25 06:58:53 +00:00
parent a38de566c6
commit 811c105c24
13 changed files with 224 additions and 175 deletions
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21
src/LinearMath/btScalar.h
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@@ -154,7 +154,26 @@ SIMD_FORCE_INLINE btScalar btPow(btScalar x,btScalar y) { return pow(x,y); }
#else
SIMD_FORCE_INLINE btScalar btSqrt(btScalar x) { return sqrtf(x); }
SIMD_FORCE_INLINE btScalar btSqrt(btScalar y)
{
#ifdef USE_APPROXIMATION
double x, z, tempf;
unsigned long *tfptr = ((unsigned long *)&tempf) + 1;
tempf = y;
*tfptr = (0xbfcdd90a - *tfptr)>>1; /* estimate of 1/sqrt(y) */
x = tempf;
z = y*btScalar(0.5); /* hoist out the <20>/2<> */
x = (btScalar(1.5)*x)-(x*x)*(x*z); /* iteration formula */
x = (btScalar(1.5)*x)-(x*x)*(x*z);
x = (btScalar(1.5)*x)-(x*x)*(x*z);
x = (btScalar(1.5)*x)-(x*x)*(x*z);
x = (btScalar(1.5)*x)-(x*x)*(x*z);
return x*y;
#else
return sqrtf(y);
#endif
}
SIMD_FORCE_INLINE btScalar btFabs(btScalar x) { return fabsf(x); }
SIMD_FORCE_INLINE btScalar btCos(btScalar x) { return cosf(x); }
SIMD_FORCE_INLINE btScalar btSin(btScalar x) { return sinf(x); }