forked from KolibriOS/kolibrios
74 lines
2.1 KiB
C
74 lines
2.1 KiB
C
/**************************************************************************
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*
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* Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
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* All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* 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, sub license, 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 (including the
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* next paragraph) shall be included in all copies or substantial portions
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* of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
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* IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
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* ANY 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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#include "util/u_math.h"
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/** 2^x, for x in [-1.0, 1.0) */
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float pow2_table[POW2_TABLE_SIZE];
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static void
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init_pow2_table(void)
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{
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int i;
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for (i = 0; i < POW2_TABLE_SIZE; i++)
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pow2_table[i] = (float) pow(2.0, (i - POW2_TABLE_OFFSET) / POW2_TABLE_SCALE);
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}
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/** log2(x), for x in [1.0, 2.0) */
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float log2_table[LOG2_TABLE_SIZE];
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static void
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init_log2_table(void)
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{
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unsigned i;
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for (i = 0; i < LOG2_TABLE_SIZE; i++)
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log2_table[i] = (float) log2(1.0 + i * (1.0 / LOG2_TABLE_SCALE));
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}
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/**
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* One time init for math utilities.
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*/
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void
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util_init_math(void)
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{
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static boolean initialized = FALSE;
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if (!initialized) {
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init_pow2_table();
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init_log2_table();
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initialized = TRUE;
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}
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}
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