3d_fastmath.h File Reference

Defines math related functions. More...

#include <cmath>
#include <cstdint>
#include <cstring>

Go to the source code of this file.

Macros
#define	FASTMATH_USE
#define	L1_CACHE_LINE_SIZE   64
#define	INTFLOORF(s)   (lrintf( (s) - (0.5f - FLT_EPSILON) ))

Functions
float	Fast_RandFloat ()
int	Fast_rand (void)
void	Fast_srand (unsigned int seed)
uint32_t	FloatToBits (float f)
	This part contains some functions from the PBRT 3 source code. More...
float	BitsToFloat (uint32_t ui)
uint64_t	FloatToBits (double f)
double	BitsToFloat (uint64_t ui)
float	NextFloatUp (float v)
float	NextFloatDown (float v)

Detailed Description

Defines math related functions.

Definition in file 3d_fastmath.h.

Macro Definition Documentation

FASTMATH_USE

#define FASTMATH_USE

Definition at line 39 of file 3d_fastmath.h.

INTFLOORF

#define INTFLOORF

(

s

)

(lrintf( (s) - (0.5f - FLT_EPSILON) ))

Definition at line 44 of file 3d_fastmath.h.

L1_CACHE_LINE_SIZE

#define L1_CACHE_LINE_SIZE   64

Definition at line 41 of file 3d_fastmath.h.

Function Documentation

BitsToFloat() [1/2]

float BitsToFloat ( uint32_t  ui )

inline

Definition at line 106 of file 3d_fastmath.h.

{
 float f;
 
 memcpy( &f, &ui, sizeof (uint32_t ) );
 
 return f;
}

Referenced by NextFloatDown(), and NextFloatUp().

BitsToFloat() [2/2]

double BitsToFloat ( uint64_t  ui )

inline

Definition at line 126 of file 3d_fastmath.h.

{
 double f;
 
 memcpy( &f, &ui, sizeof( uint64_t ) );
 
 return f;
}

Fast_rand()

int Fast_rand

(

void

)

Definition at line 58 of file 3d_fastmath.cpp.

{
 s_nextRandSeed = s_nextRandSeed * 1103515245 + 12345;
 
 return (unsigned int)(s_nextRandSeed >> 16) & 0x7FFF;
}

References s_nextRandSeed.

Referenced by POST_SHADER_SSAO::Shade().

Fast_RandFloat()

float Fast_RandFloat

(

)

Definition at line 45 of file 3d_fastmath.cpp.

{
 s_randSeed *= 16807;
 
 return (float)s_randSeed * 4.6566129e-010f;
}

References s_randSeed.

Referenced by RAYPACKET::RAYPACKET(), RAYPACKET_InitRays_with2DDisplacement(), and UniformRandomHemisphereDirection().

Fast_srand()

void Fast_srand

(

unsigned int

seed

)

Definition at line 65 of file 3d_fastmath.cpp.

{
 s_nextRandSeed = seed;
}

References s_nextRandSeed.

FloatToBits() [1/2]

uint64_t FloatToBits ( double  f )

inline

Definition at line 116 of file 3d_fastmath.h.

{
 uint64_t ui;
 
 memcpy( &ui, &f, sizeof( double ) );
 
 return ui;
}

FloatToBits() [2/2]

uint32_t FloatToBits ( float  f )

inline

This part contains some functions from the PBRT 3 source code.

https://github.com/mmp/pbrt-v3/blob/master/src/core/pbrt.h

Definition at line 96 of file 3d_fastmath.h.

{
 uint32_t ui;
 
 memcpy( &ui, &f, sizeof( float ) );
 
 return ui;
}

Referenced by NextFloatDown(), and NextFloatUp().

NextFloatDown()

float NextFloatDown ( float  v )

inline

Definition at line 157 of file 3d_fastmath.h.

{
 // Handle infinity and positive zero for _NextFloatDown()_
 if( std::isinf( v ) && (v < 0.) )
 return v;
 
 if( v == 0.f )
 v = -0.f;
 
 uint32_t ui = FloatToBits( v );
 
 if( v > 0. )
 --ui;
 else
 ++ui;
 
 return BitsToFloat( ui );
}

References BitsToFloat(), and FloatToBits().

Referenced by LAYER_ITEM::Intersect(), LAYER_ITEM::IntersectP(), RAYSEG2D::RAYSEG2D(), RENDER_3D_RAYTRACE::Reload(), BBOX_2D::ScaleNextDown(), BBOX_3D::ScaleNextDown(), BBOX_2D::ScaleNextUp(), and BBOX_3D::ScaleNextUp().

NextFloatUp()

float NextFloatUp ( float  v )

inline

Definition at line 136 of file 3d_fastmath.h.

{
 // Handle infinity and negative zero for _NextFloatUp()_
 if( std::isinf( v ) && (v > 0.) )
 return v;
 
 if( v == -0.f )
 v = 0.f;
 
 // Advance _v_ to next higher float
 uint32_t ui = FloatToBits( v );
 
 if( v >= 0. )
 ++ui;
 else
 --ui;
 
 return BitsToFloat( ui );
}

References BitsToFloat(), and FloatToBits().

Referenced by LAYER_ITEM::Intersect(), LAYER_ITEM::IntersectP(), RENDER_3D_RAYTRACE::Reload(), BBOX_2D::ScaleNextDown(), BBOX_3D::ScaleNextDown(), BBOX_2D::ScaleNextUp(), and BBOX_3D::ScaleNextUp().