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mathlib: make Gain and Bias inline

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This commit is contained in:
nillerusr 2023-04-26 22:33:20 +03:00
parent 7ceba77616
commit e3edbc2d96
2 changed files with 21 additions and 31 deletions
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27
mathlib/mathlib_base.cpp
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@ -1392,33 +1392,6 @@ void VectorYawRotate( const Vector &in, float flYaw, Vector &out)
out.z = in.z;
}
float Bias( float x, float biasAmt )
{
// WARNING: not thread safe
static float lastAmt = -1;
static float lastExponent = 0;
if( lastAmt != biasAmt )
{
lastExponent = log( biasAmt ) * -1.4427f; // (-1.4427 = 1 / log(0.5))
}
float fRet = pow( x, lastExponent );
Assert ( !IS_NAN( fRet ) );
return fRet;
}
float Gain( float x, float biasAmt )
{
// WARNING: not thread safe
if( x < 0.5 )
return 0.5f * Bias( 2*x, 1-biasAmt );
else
return 1 - 0.5f * Bias( 2 - 2*x, 1-biasAmt );
}
float SmoothCurve( float x )
{
// Actual smooth curve. Visualization:

25
public/mathlib/mathlib.h
View File

@ -1082,7 +1082,19 @@ void VectorYawRotate( const Vector& in, float flYaw, Vector &out);
// 0 1
//
// With a biasAmt of 0.5, Bias returns X.
float Bias( float x, float biasAmt );
inline float Bias( float x, float biasAmt )
{
// WARNING: not thread safe
static float lastAmt = -1;
static float lastExponent = 0;
if( lastAmt != biasAmt )
{
lastExponent = log( biasAmt ) * -1.4427f; // (-1.4427 = 1 / log(0.5))
}
float fRet = pow( x, lastExponent );
Assert ( !IS_NAN( fRet ) );
return fRet;
}
// Gain is similar to Bias, but biasAmt biases towards or away from 0.5.
@ -1114,9 +1126,14 @@ float Bias( float x, float biasAmt );
// |*****
// |___________________
// 0 1
float Gain( float x, float biasAmt );
inline float Gain( float x, float biasAmt )
{
// WARNING: not thread safe
if( x < 0.5 )
return 0.5f * Bias( 2*x, 1-biasAmt );
else
return 1 - 0.5f * Bias( 2 - 2*x, 1-biasAmt );
}
// SmoothCurve maps a 0-1 value into another 0-1 value based on a cosine wave
// where the derivatives of the function at 0 and 1 (and 0.5) are 0. This is useful for
// any fadein/fadeout effect where it should start and end smoothly.