140 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			140 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
///////////////////////////////////////////////////////////////////////////
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//
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// Copyright (c) 2002, 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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//-----------------------------------------------------------------------------
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//
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//	Routines for converting between pixel data types,
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//	with well-defined behavior for exceptional cases.
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//
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//-----------------------------------------------------------------------------
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#include <ImfConvert.h>
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#include <limits.h>
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namespace Imf {
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namespace {
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inline bool
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isNegative (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 & 0x80000000) != 0;
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}
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inline bool
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isNan (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 & 0x7fffffff) > 0x7f800000;
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}
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inline bool
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isInfinity (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 & 0x7fffffff) == 0x7f800000;
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}
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inline bool
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isFinite (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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} // namespace
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unsigned int
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halfToUint (half h)
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{
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    if (h.isNegative() || h.isNan())
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    return 0;
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    if (h.isInfinity())
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    return UINT_MAX;
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    return (unsigned int) h;
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}
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unsigned int
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floatToUint (float f)
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{
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    if (isNegative (f) || isNan (f))
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    return 0;
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    if (isInfinity (f) || f > UINT_MAX)
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    return UINT_MAX;
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    return (unsigned int) f;
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}
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half
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uintToHalf (unsigned int ui)
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{
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    if (ui >  HALF_MAX)
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    return half::posInf();
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    return half (ui);
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}
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half
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floatToHalf (float f)
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{
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    if (isFinite (f))
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    {
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    if (f >  HALF_MAX)
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        return half::posInf();
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    if (f < -HALF_MAX)
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        return half::negInf();
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    }
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    return half (f);
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}
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} // namespace Imf
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