52 lines
1.9 KiB
C++
52 lines
1.9 KiB
C++
/**
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* @file llsmoothstep.h
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* @brief Smoothstep - transition from 0 to 1 - function, first and second derivatives all continuous (smooth)
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*
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* $LicenseInfo:firstyear=2001&license=viewergpl$
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*
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* Copyright (c) 2001-2009, Linden Research, Inc.
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*
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* Second Life Viewer Source Code
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* The source code in this file ("Source Code") is provided by Linden Lab
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* to you under the terms of the GNU General Public License, version 2.0
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* ("GPL"), unless you have obtained a separate licensing agreement
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* ("Other License"), formally executed by you and Linden Lab. Terms of
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* the GPL can be found in doc/GPL-license.txt in this distribution, or
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* online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
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*
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* There are special exceptions to the terms and conditions of the GPL as
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* it is applied to this Source Code. View the full text of the exception
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* in the file doc/FLOSS-exception.txt in this software distribution, or
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* online at
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* http://secondlifegrid.net/programs/open_source/licensing/flossexception
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*
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* By copying, modifying or distributing this software, you acknowledge
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* that you have read and understood your obligations described above,
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* and agree to abide by those obligations.
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*
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* ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
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* WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
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* COMPLETENESS OR PERFORMANCE.
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* $/LicenseInfo$
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*/
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#ifndef LL_LLSMOOTHSTEP_H
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#define LL_LLSMOOTHSTEP_H
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template <class LLDATATYPE>
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inline LLDATATYPE llsmoothstep(const LLDATATYPE& edge0, const LLDATATYPE& edge1, const LLDATATYPE& value)
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{
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if (value < edge0)
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return (LLDATATYPE)0;
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if (value >= edge1)
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return (LLDATATYPE)1;
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// Scale/bias into [0..1] range
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LLDATATYPE scaled_value = (value - edge0) / (edge1 - edge0);
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return scaled_value * scaled_value * (3 - 2 * scaled_value);
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}
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#endif // LL_LLSMOOTHSTEP_H
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