raze-gles/polymer/eduke32/source/android/etcpak/Math.hpp

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#ifndef __DARKRL__MATH_HPP__
#define __DARKRL__MATH_HPP__
#include <algorithm>
#include "Types.hpp"
template<typename T>
inline T AlignPOT( T val )
{
if( val == 0 ) return 1;
val--;
for( unsigned int i=1; i<sizeof( T ) * 8; i <<= 1 )
{
val |= val >> i;
}
return val + 1;
}
inline int CountSetBits( uint32 val )
{
val -= ( val >> 1 ) & 0x55555555;
val = ( ( val >> 2 ) & 0x33333333 ) + ( val & 0x33333333 );
val = ( ( val >> 4 ) + val ) & 0x0f0f0f0f;
val += val >> 8;
val += val >> 16;
return val & 0x0000003f;
}
inline int CountLeadingZeros( uint32 val )
{
val |= val >> 1;
val |= val >> 2;
val |= val >> 4;
val |= val >> 8;
val |= val >> 16;
return 32 - CountSetBits( val );
}
inline float sRGB2linear( float v )
{
const float a = 0.055f;
if( v <= 0.04045f )
{
return v / 12.92f;
}
else
{
return pow( ( v + a ) / ( 1 + a ), 2.4f );
}
}
inline float linear2sRGB( float v )
{
const float a = 0.055f;
if( v <= 0.0031308f )
{
return 12.92f * v;
}
else
{
return ( 1 + a ) * pow( v, 1/2.4f ) - a;
}
}
template<class T>
inline T SmoothStep( T x )
{
return x*x*(3-2*x);
}
inline uint8 clampu8( int32 val )
{
return std::min( std::max( 0, val ), 255 );
}
template<class T>
inline T sq( T val )
{
return val * val;
}
static inline int mul8bit( int a, int b )
{
int t = a*b + 128;
return ( t + ( t >> 8 ) ) >> 8;
}
#endif