285 lines
7.2 KiB
Plaintext
285 lines
7.2 KiB
Plaintext
|
/// Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||
|
|
///
|
||
|
|
/// Developed at SunPro, a Sun Microsystems, Inc. business.
|
||
|
|
/// Permission to use, copy, modify, and distribute this
|
||
|
|
/// software is freely granted, provided that this notice
|
||
|
|
/// is preserved.
|
||
|
|
|
||
|
|
#include "../detail/type_float.hpp"
|
||
|
|
#include "../ext/scalar_constants.hpp"
|
||
|
|
#include <cmath>
|
||
|
|
#include <cfloat>
|
||
|
|
|
||
|
|
#if(GLM_COMPILER & GLM_COMPILER_VC)
|
||
|
|
# pragma warning(push)
|
||
|
|
# pragma warning(disable : 4127)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
typedef union
|
||
|
|
{
|
||
|
|
float value;
|
||
|
|
/* FIXME: Assumes 32 bit int. */
|
||
|
|
unsigned int word;
|
||
|
|
} ieee_float_shape_type;
|
||
|
|
|
||
|
|
typedef union
|
||
|
|
{
|
||
|
|
double value;
|
||
|
|
struct
|
||
|
|
{
|
||
|
|
int lsw;
|
||
|
|
int msw;
|
||
|
|
} parts;
|
||
|
|
} ieee_double_shape_type;
|
||
|
|
|
||
|
|
#define GLM_EXTRACT_WORDS(ix0,ix1,d) \
|
||
|
|
do { \
|
||
|
|
ieee_double_shape_type ew_u; \
|
||
|
|
ew_u.value = (d); \
|
||
|
|
(ix0) = ew_u.parts.msw; \
|
||
|
|
(ix1) = ew_u.parts.lsw; \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
#define GLM_GET_FLOAT_WORD(i,d) \
|
||
|
|
do { \
|
||
|
|
ieee_float_shape_type gf_u; \
|
||
|
|
gf_u.value = (d); \
|
||
|
|
(i) = gf_u.word; \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
#define GLM_SET_FLOAT_WORD(d,i) \
|
||
|
|
do { \
|
||
|
|
ieee_float_shape_type sf_u; \
|
||
|
|
sf_u.word = (i); \
|
||
|
|
(d) = sf_u.value; \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
#define GLM_INSERT_WORDS(d,ix0,ix1) \
|
||
|
|
do { \
|
||
|
|
ieee_double_shape_type iw_u; \
|
||
|
|
iw_u.parts.msw = (ix0); \
|
||
|
|
iw_u.parts.lsw = (ix1); \
|
||
|
|
(d) = iw_u.value; \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
namespace glm{
|
||
|
|
namespace detail
|
||
|
|
{
|
||
|
|
GLM_FUNC_QUALIFIER float nextafterf(float x, float y)
|
||
|
|
{
|
||
|
|
volatile float t;
|
||
|
|
int hx, hy, ix, iy;
|
||
|
|
|
||
|
|
GLM_GET_FLOAT_WORD(hx, x);
|
||
|
|
GLM_GET_FLOAT_WORD(hy, y);
|
||
|
|
ix = hx & 0x7fffffff; // |x|
|
||
|
|
iy = hy & 0x7fffffff; // |y|
|
||
|
|
|
||
|
|
if((ix > 0x7f800000) || // x is nan
|
||
|
|
(iy > 0x7f800000)) // y is nan
|
||
|
|
return x + y;
|
||
|
|
if(abs(y - x) <= epsilon<float>())
|
||
|
|
return y; // x=y, return y
|
||
|
|
if(ix == 0)
|
||
|
|
{ // x == 0
|
||
|
|
GLM_SET_FLOAT_WORD(x, (hy & 0x80000000) | 1);// return +-minsubnormal
|
||
|
|
t = x * x;
|
||
|
|
if(abs(t - x) <= epsilon<float>())
|
||
|
|
return t;
|
||
|
|
else
|
||
|
|
return x; // raise underflow flag
|
||
|
|
}
|
||
|
|
if(hx >= 0)
|
||
|
|
{ // x > 0
|
||
|
|
if(hx > hy) // x > y, x -= ulp
|
||
|
|
hx -= 1;
|
||
|
|
else // x < y, x += ulp
|
||
|
|
hx += 1;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{ // x < 0
|
||
|
|
if(hy >= 0 || hx > hy) // x < y, x -= ulp
|
||
|
|
hx -= 1;
|
||
|
|
else // x > y, x += ulp
|
||
|
|
hx += 1;
|
||
|
|
}
|
||
|
|
hy = hx & 0x7f800000;
|
||
|
|
if(hy >= 0x7f800000)
|
||
|
|
return x + x; // overflow
|
||
|
|
if(hy < 0x00800000) // underflow
|
||
|
|
{
|
||
|
|
t = x * x;
|
||
|
|
if(abs(t - x) > epsilon<float>())
|
||
|
|
{ // raise underflow flag
|
||
|
|
GLM_SET_FLOAT_WORD(y, hx);
|
||
|
|
return y;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
GLM_SET_FLOAT_WORD(x, hx);
|
||
|
|
return x;
|
||
|
|
}
|
||
|
|
|
||
|
|
GLM_FUNC_QUALIFIER double nextafter(double x, double y)
|
||
|
|
{
|
||
|
|
volatile double t;
|
||
|
|
int hx, hy, ix, iy;
|
||
|
|
unsigned int lx, ly;
|
||
|
|
|
||
|
|
GLM_EXTRACT_WORDS(hx, lx, x);
|
||
|
|
GLM_EXTRACT_WORDS(hy, ly, y);
|
||
|
|
ix = hx & 0x7fffffff; // |x|
|
||
|
|
iy = hy & 0x7fffffff; // |y|
|
||
|
|
|
||
|
|
if(((ix >= 0x7ff00000) && ((ix - 0x7ff00000) | lx) != 0) || // x is nan
|
||
|
|
((iy >= 0x7ff00000) && ((iy - 0x7ff00000) | ly) != 0)) // y is nan
|
||
|
|
return x + y;
|
||
|
|
if(abs(y - x) <= epsilon<double>())
|
||
|
|
return y; // x=y, return y
|
||
|
|
if((ix | lx) == 0)
|
||
|
|
{ // x == 0
|
||
|
|
GLM_INSERT_WORDS(x, hy & 0x80000000, 1); // return +-minsubnormal
|
||
|
|
t = x * x;
|
||
|
|
if(abs(t - x) <= epsilon<double>())
|
||
|
|
return t;
|
||
|
|
else
|
||
|
|
return x; // raise underflow flag
|
||
|
|
}
|
||
|
|
if(hx >= 0) { // x > 0
|
||
|
|
if(hx > hy || ((hx == hy) && (lx > ly))) { // x > y, x -= ulp
|
||
|
|
if(lx == 0) hx -= 1;
|
||
|
|
lx -= 1;
|
||
|
|
}
|
||
|
|
else { // x < y, x += ulp
|
||
|
|
lx += 1;
|
||
|
|
if(lx == 0) hx += 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else { // x < 0
|
||
|
|
if(hy >= 0 || hx > hy || ((hx == hy) && (lx > ly))){// x < y, x -= ulp
|
||
|
|
if(lx == 0) hx -= 1;
|
||
|
|
lx -= 1;
|
||
|
|
}
|
||
|
|
else { // x > y, x += ulp
|
||
|
|
lx += 1;
|
||
|
|
if(lx == 0) hx += 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
hy = hx & 0x7ff00000;
|
||
|
|
if(hy >= 0x7ff00000)
|
||
|
|
return x + x; // overflow
|
||
|
|
if(hy < 0x00100000)
|
||
|
|
{ // underflow
|
||
|
|
t = x * x;
|
||
|
|
if(abs(t - x) > epsilon<double>())
|
||
|
|
{ // raise underflow flag
|
||
|
|
GLM_INSERT_WORDS(y, hx, lx);
|
||
|
|
return y;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
GLM_INSERT_WORDS(x, hx, lx);
|
||
|
|
return x;
|
||
|
|
}
|
||
|
|
}//namespace detail
|
||
|
|
}//namespace glm
|
||
|
|
|
||
|
|
#if(GLM_COMPILER & GLM_COMPILER_VC)
|
||
|
|
# pragma warning(pop)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
namespace glm
|
||
|
|
{
|
||
|
|
template<>
|
||
|
|
GLM_FUNC_QUALIFIER float nextFloat(float x)
|
||
|
|
{
|
||
|
|
# if GLM_HAS_CXX11_STL
|
||
|
|
return std::nextafter(x, std::numeric_limits<float>::max());
|
||
|
|
# elif((GLM_COMPILER & GLM_COMPILER_VC) || ((GLM_COMPILER & GLM_COMPILER_INTEL) && (GLM_PLATFORM & GLM_PLATFORM_WINDOWS)))
|
||
|
|
return detail::nextafterf(x, FLT_MAX);
|
||
|
|
# elif(GLM_PLATFORM & GLM_PLATFORM_ANDROID)
|
||
|
|
return __builtin_nextafterf(x, FLT_MAX);
|
||
|
|
# else
|
||
|
|
return nextafterf(x, FLT_MAX);
|
||
|
|
# endif
|
||
|
|
}
|
||
|
|
|
||
|
|
template<>
|
||
|
|
GLM_FUNC_QUALIFIER double nextFloat(double x)
|
||
|
|
{
|
||
|
|
# if GLM_HAS_CXX11_STL
|
||
|
|
return std::nextafter(x, std::numeric_limits<double>::max());
|
||
|
|
# elif((GLM_COMPILER & GLM_COMPILER_VC) || ((GLM_COMPILER & GLM_COMPILER_INTEL) && (GLM_PLATFORM & GLM_PLATFORM_WINDOWS)))
|
||
|
|
return detail::nextafter(x, std::numeric_limits<double>::max());
|
||
|
|
# elif(GLM_PLATFORM & GLM_PLATFORM_ANDROID)
|
||
|
|
return __builtin_nextafter(x, DBL_MAX);
|
||
|
|
# else
|
||
|
|
return nextafter(x, DBL_MAX);
|
||
|
|
# endif
|
||
|
|
}
|
||
|
|
|
||
|
|
template<typename T>
|
||
|
|
GLM_FUNC_QUALIFIER T nextFloat(T x, int ULPs)
|
||
|
|
{
|
||
|
|
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559, "'next_float' only accept floating-point input");
|
||
|
|
assert(ULPs >= 0);
|
||
|
|
|
||
|
|
T temp = x;
|
||
|
|
for(int i = 0; i < ULPs; ++i)
|
||
|
|
temp = nextFloat(temp);
|
||
|
|
return temp;
|
||
|
|
}
|
||
|
|
|
||
|
|
GLM_FUNC_QUALIFIER float prevFloat(float x)
|
||
|
|
{
|
||
|
|
# if GLM_HAS_CXX11_STL
|
||
|
|
return std::nextafter(x, std::numeric_limits<float>::min());
|
||
|
|
# elif((GLM_COMPILER & GLM_COMPILER_VC) || ((GLM_COMPILER & GLM_COMPILER_INTEL) && (GLM_PLATFORM & GLM_PLATFORM_WINDOWS)))
|
||
|
|
return detail::nextafterf(x, FLT_MIN);
|
||
|
|
# elif(GLM_PLATFORM & GLM_PLATFORM_ANDROID)
|
||
|
|
return __builtin_nextafterf(x, FLT_MIN);
|
||
|
|
# else
|
||
|
|
return nextafterf(x, FLT_MIN);
|
||
|
|
# endif
|
||
|
|
}
|
||
|
|
|
||
|
|
GLM_FUNC_QUALIFIER double prevFloat(double x)
|
||
|
|
{
|
||
|
|
# if GLM_HAS_CXX11_STL
|
||
|
|
return std::nextafter(x, std::numeric_limits<double>::min());
|
||
|
|
# elif((GLM_COMPILER & GLM_COMPILER_VC) || ((GLM_COMPILER & GLM_COMPILER_INTEL) && (GLM_PLATFORM & GLM_PLATFORM_WINDOWS)))
|
||
|
|
return _nextafter(x, DBL_MIN);
|
||
|
|
# elif(GLM_PLATFORM & GLM_PLATFORM_ANDROID)
|
||
|
|
return __builtin_nextafter(x, DBL_MIN);
|
||
|
|
# else
|
||
|
|
return nextafter(x, DBL_MIN);
|
||
|
|
# endif
|
||
|
|
}
|
||
|
|
|
||
|
|
template<typename T>
|
||
|
|
GLM_FUNC_QUALIFIER T prevFloat(T x, int ULPs)
|
||
|
|
{
|
||
|
|
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559, "'prev_float' only accept floating-point input");
|
||
|
|
assert(ULPs >= 0);
|
||
|
|
|
||
|
|
T temp = x;
|
||
|
|
for(int i = 0; i < ULPs; ++i)
|
||
|
|
temp = prevFloat(temp);
|
||
|
|
return temp;
|
||
|
|
}
|
||
|
|
|
||
|
|
GLM_FUNC_QUALIFIER int floatDistance(float x, float y)
|
||
|
|
{
|
||
|
|
detail::float_t<float> const a(x);
|
||
|
|
detail::float_t<float> const b(y);
|
||
|
|
|
||
|
|
return abs(a.i - b.i);
|
||
|
|
}
|
||
|
|
|
||
|
|
GLM_FUNC_QUALIFIER int64 floatDistance(double x, double y)
|
||
|
|
{
|
||
|
|
detail::float_t<double> const a(x);
|
||
|
|
detail::float_t<double> const b(y);
|
||
|
|
|
||
|
|
return abs(a.i - b.i);
|
||
|
|
}
|
||
|
|
}//namespace glm
|