1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/assimp/qnan.h	Sat Feb 01 19:58:19 2014 +0200
     1.3 @@ -0,0 +1,110 @@
     1.4 +/*
     1.5 +---------------------------------------------------------------------------
     1.6 +Open Asset Import Library (assimp)
     1.7 +---------------------------------------------------------------------------
     1.8 +
     1.9 +Copyright (c) 2006-2012, assimp team
    1.10 +
    1.11 +All rights reserved.
    1.12 +
    1.13 +Redistribution and use of this software in source and binary forms, 
    1.14 +with or without modification, are permitted provided that the following 
    1.15 +conditions are met:
    1.16 +
    1.17 +* Redistributions of source code must retain the above
    1.18 +  copyright notice, this list of conditions and the
    1.19 +  following disclaimer.
    1.20 +
    1.21 +* Redistributions in binary form must reproduce the above
    1.22 +  copyright notice, this list of conditions and the
    1.23 +  following disclaimer in the documentation and/or other
    1.24 +  materials provided with the distribution.
    1.25 +
    1.26 +* Neither the name of the assimp team, nor the names of its
    1.27 +  contributors may be used to endorse or promote products
    1.28 +  derived from this software without specific prior
    1.29 +  written permission of the assimp team.
    1.30 +
    1.31 +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
    1.32 +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
    1.33 +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    1.34 +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
    1.35 +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    1.36 +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
    1.37 +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    1.38 +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
    1.39 +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
    1.40 +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
    1.41 +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    1.42 +---------------------------------------------------------------------------
    1.43 +*/
    1.44 +
    1.45 +/**  @file  qnan.h
    1.46 + *   @brief Some utilities for our dealings with qnans.
    1.47 + *
    1.48 + *   @note Some loaders use qnans to mark invalid values tempoarily, also
    1.49 + *     Assimp explicitly enforces undefined normals to be set to qnan.
    1.50 + *     qnan utilities are available in standard libraries (C99 for example)
    1.51 + *     but last time I checked compiler coverage was so bad that I decided
    1.52 + *     to reinvent the wheel.
    1.53 + */
    1.54 +
    1.55 +#ifndef AI_QNAN_H_INCLUDED
    1.56 +#define AI_QNAN_H_INCLUDED
    1.57 +
    1.58 +// ---------------------------------------------------------------------------
    1.59 +/** Data structure to represent the bit pattern of a 32 Bit 
    1.60 + *         IEEE 754 floating-point number. */
    1.61 +union _IEEESingle
    1.62 +{
    1.63 +	float Float;
    1.64 +	struct
    1.65 +	{
    1.66 +		uint32_t Frac : 23;
    1.67 +		uint32_t Exp  : 8;
    1.68 +		uint32_t Sign : 1;
    1.69 +	} IEEE;
    1.70 +} ;
    1.71 +
    1.72 +// ---------------------------------------------------------------------------
    1.73 +/** Check whether a given float is qNaN. 
    1.74 + *  @param in Input value */
    1.75 +AI_FORCE_INLINE bool is_qnan(float in)	
    1.76 +{
    1.77 +	// the straightforward solution does not work:
    1.78 +	//   return (in != in);
    1.79 +	// compiler generates code like this
    1.80 +	//   load <in> to <register-with-different-width>
    1.81 +	//   compare <register-with-different-width> against <in>
    1.82 +
    1.83 +	// FIXME: Use <float> stuff instead? I think fpclassify needs C99
    1.84 +	return (reinterpret_cast<_IEEESingle*>(&in)->IEEE.Exp == (1u << 8)-1 &&
    1.85 +		reinterpret_cast<_IEEESingle*>(&in)->IEEE.Frac);
    1.86 +}
    1.87 +
    1.88 +// ---------------------------------------------------------------------------
    1.89 +/** Check whether a float is NOT qNaN. 
    1.90 + *  @param in Input value */
    1.91 +AI_FORCE_INLINE bool is_not_qnan(float in)	
    1.92 +{
    1.93 +	return !is_qnan(in);
    1.94 +}
    1.95 +
    1.96 +// ---------------------------------------------------------------------------
    1.97 +/** @brief check whether a float is either NaN or (+/-) INF. 
    1.98 + *
    1.99 + *  Denorms return false, they're treated like normal values.
   1.100 + *  @param in Input value */
   1.101 +AI_FORCE_INLINE bool is_special_float(float in)
   1.102 +{
   1.103 +	return (reinterpret_cast<_IEEESingle*>(&in)->IEEE.Exp == (1u << 8)-1);
   1.104 +}
   1.105 +
   1.106 +// ---------------------------------------------------------------------------
   1.107 +/** @brief Get a fresh qnan.  */
   1.108 +AI_FORCE_INLINE float get_qnan()
   1.109 +{
   1.110 +	return std::numeric_limits<float>::quiet_NaN();
   1.111 +}
   1.112 +
   1.113 +#endif // !! AI_QNAN_H_INCLUDED