elexis
43137fef3f
Differential Revision: https://code.wildfiregames.com/D716
Refs 09e974e1cb
Reviewed By: bb
Change in agreement with leper.
This was SVN commit r19899.
43 lines
1.4 KiB
C++
43 lines
1.4 KiB
C++
/* Copyright (C) 2010 Wildfire Games.
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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/*
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* bit-twiddling.
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*/
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#include "precompiled.h"
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#include "lib/bits.h"
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static inline u32 get_float_bits(const float x)
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{
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u32 ret;
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memcpy(&ret, &x, 4);
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return ret;
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}
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int floor_log2(const float x)
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{
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const u32 i = get_float_bits(x);
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const u32 biased_exp = (i >> 23) & 0xFF;
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return (int)biased_exp - 127;
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}
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