[823] | 1 | /******************************************************************************
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| 2 | Copyright (c) 2014 Ryan Juckett
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| 3 | http://www.ryanjuckett.com/
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| 4 |
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| 5 | This software is provided 'as-is', without any express or implied
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| 6 | warranty. In no event will the authors be held liable for any damages
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| 7 | arising from the use of this software.
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| 8 |
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| 9 | Permission is granted to anyone to use this software for any purpose,
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| 10 | including commercial applications, and to alter it and redistribute it
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| 11 | freely, subject to the following restrictions:
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| 12 |
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| 13 | 1. The origin of this software must not be misrepresented; you must not
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| 14 | claim that you wrote the original software. If you use this software
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| 15 | in a product, an acknowledgment in the product documentation would be
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| 16 | appreciated but is not required.
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| 17 |
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| 18 | 2. Altered source versions must be plainly marked as such, and must not be
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| 19 | misrepresented as being the original software.
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| 20 |
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| 21 | 3. This notice may not be removed or altered from any source
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| 22 | distribution.
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| 23 | ******************************************************************************/
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| 24 |
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| 25 | #ifndef RJ__Math_h
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| 26 | #define RJ__Math_h
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| 27 |
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| 28 | #include "Standard.h"
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| 29 |
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| 30 | //******************************************************************************
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| 31 | // Get the log base 2 of a 32-bit unsigned integer.
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| 32 | // http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogLookup
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| 33 | //******************************************************************************
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| 34 | tU32 LogBase2( tU32 val );
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| 35 |
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| 36 | //******************************************************************************
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| 37 | // Get the log base 2 of a 64-bit unsigned integer.
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| 38 | //******************************************************************************
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| 39 | inline tU32 LogBase2( tU64 val )
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| 40 | {
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| 41 | tU64 temp;
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| 42 |
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| 43 | temp = val >> 32;
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| 44 | if (temp)
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| 45 | return 32 + LogBase2((tU32)temp);
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| 46 |
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| 47 | return LogBase2((tU32)val);
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| 48 | }
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| 49 |
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| 50 | #endif
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