src/gallium/auxiliary/util/u_math.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
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  25  *
  26  **************************************************************************/
  27
  28
  29
  30 #include "util/u_math.h"
  31
  32
  33
  34 float pow2_table[POW2_TABLE_SIZE];
  35
  36
  37 static void
  38 init_pow2_table(void)
  39 {
  40    int i;
  41    for (i = 0; i < POW2_TABLE_SIZE; i++) {
  42       pow2_table[i] = (float) pow(2.0, i / POW2_TABLE_SCALE);
  43    }
  44 }
  45
  46
  47 /**
  48  * One time init for math utilities.
  49  */
  50 void
  51 util_init_math(void)
  52 {
  53    static boolean initialized = FALSE;
  54    if (!initialized) {
  55       init_pow2_table();
  56       initialized = TRUE;
  57    }
  58 }
  59
  60