270 lines
6.0 KiB
C++
270 lines
6.0 KiB
C++
///////////////////////////////////////////////////////////////////////////
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//
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// Copyright (c) 2002-2012, Industrial Light & Magic, a division of Lucas
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// Digital Ltd. LLC
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//
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// All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following disclaimer
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// in the documentation and/or other materials provided with the
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// distribution.
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// * Neither the name of Industrial Light & Magic nor the names of
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// its contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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///////////////////////////////////////////////////////////////////////////
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#ifndef INCLUDED_IMATHFUN_H
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#define INCLUDED_IMATHFUN_H
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//-----------------------------------------------------------------------------
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//
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// Miscellaneous utility functions
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//
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//-----------------------------------------------------------------------------
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#include "ImathExport.h"
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#include "ImathLimits.h"
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#include "ImathInt64.h"
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#include "ImathNamespace.h"
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IMATH_INTERNAL_NAMESPACE_HEADER_ENTER
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template <class T>
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inline T
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abs (T a)
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{
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return (a > T(0)) ? a : -a;
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}
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template <class T>
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inline int
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sign (T a)
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{
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return (a > T(0))? 1 : ((a < T(0)) ? -1 : 0);
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}
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template <class T, class Q>
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inline T
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lerp (T a, T b, Q t)
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{
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return (T) (a * (1 - t) + b * t);
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}
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template <class T, class Q>
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inline T
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ulerp (T a, T b, Q t)
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{
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return (T) ((a > b)? (a - (a - b) * t): (a + (b - a) * t));
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}
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template <class T>
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inline T
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lerpfactor(T m, T a, T b)
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{
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//
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// Return how far m is between a and b, that is return t such that
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// if:
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// t = lerpfactor(m, a, b);
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// then:
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// m = lerp(a, b, t);
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//
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// If a==b, return 0.
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//
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T d = b - a;
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T n = m - a;
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if (abs(d) > T(1) || abs(n) < limits<T>::max() * abs(d))
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return n / d;
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return T(0);
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}
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template <class T>
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inline T
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clamp (T a, T l, T h)
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{
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return (a < l)? l : ((a > h)? h : a);
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}
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template <class T>
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inline int
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cmp (T a, T b)
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{
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return IMATH_INTERNAL_NAMESPACE::sign (a - b);
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}
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template <class T>
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inline int
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cmpt (T a, T b, T t)
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{
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return (IMATH_INTERNAL_NAMESPACE::abs (a - b) <= t)? 0 : cmp (a, b);
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}
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template <class T>
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inline bool
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iszero (T a, T t)
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{
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return (IMATH_INTERNAL_NAMESPACE::abs (a) <= t) ? 1 : 0;
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}
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template <class T1, class T2, class T3>
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inline bool
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equal (T1 a, T2 b, T3 t)
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{
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return IMATH_INTERNAL_NAMESPACE::abs (a - b) <= t;
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}
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template <class T>
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inline int
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floor (T x)
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{
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return (x >= 0)? int (x): -(int (-x) + (-x > int (-x)));
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}
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template <class T>
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inline int
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ceil (T x)
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{
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return -floor (-x);
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}
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template <class T>
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inline int
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trunc (T x)
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{
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return (x >= 0) ? int(x) : -int(-x);
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}
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//
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// Integer division and remainder where the
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// remainder of x/y has the same sign as x:
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//
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// divs(x,y) == (abs(x) / abs(y)) * (sign(x) * sign(y))
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// mods(x,y) == x - y * divs(x,y)
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//
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inline int
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divs (int x, int y)
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{
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return (x >= 0)? ((y >= 0)? ( x / y): -( x / -y)):
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((y >= 0)? -(-x / y): (-x / -y));
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}
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inline int
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mods (int x, int y)
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{
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return (x >= 0)? ((y >= 0)? ( x % y): ( x % -y)):
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((y >= 0)? -(-x % y): -(-x % -y));
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}
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//
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// Integer division and remainder where the
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// remainder of x/y is always positive:
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//
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// divp(x,y) == floor (double(x) / double (y))
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// modp(x,y) == x - y * divp(x,y)
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//
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inline int
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divp (int x, int y)
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{
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return (x >= 0)? ((y >= 0)? ( x / y): -( x / -y)):
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((y >= 0)? -((y-1-x) / y): ((-y-1-x) / -y));
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}
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inline int
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modp (int x, int y)
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{
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return x - y * divp (x, y);
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}
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//----------------------------------------------------------
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// Successor and predecessor for floating-point numbers:
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//
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// succf(f) returns float(f+e), where e is the smallest
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// positive number such that float(f+e) != f.
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//
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// predf(f) returns float(f-e), where e is the smallest
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// positive number such that float(f-e) != f.
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//
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// succd(d) returns double(d+e), where e is the smallest
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// positive number such that double(d+e) != d.
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//
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// predd(d) returns double(d-e), where e is the smallest
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// positive number such that double(d-e) != d.
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//
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// Exceptions: If the input value is an infinity or a nan,
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// succf(), predf(), succd(), and predd() all
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// return the input value without changing it.
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//
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//----------------------------------------------------------
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IMATH_EXPORT float succf (float f);
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IMATH_EXPORT float predf (float f);
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IMATH_EXPORT double succd (double d);
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IMATH_EXPORT double predd (double d);
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//
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// Return true if the number is not a NaN or Infinity.
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//
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inline bool
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finitef (float f)
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{
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union {float f; int i;} u;
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u.f = f;
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return (u.i & 0x7f800000) != 0x7f800000;
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}
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inline bool
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finited (double d)
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{
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union {double d; Int64 i;} u;
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u.d = d;
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return (u.i & 0x7ff0000000000000LL) != 0x7ff0000000000000LL;
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}
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IMATH_INTERNAL_NAMESPACE_HEADER_EXIT
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#endif // INCLUDED_IMATHFUN_H
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