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
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28
29
30#include "util/u_math.h"
31
32
33/** 2^x, for x in [-1.0, 1.0) */
34float pow2_table[POW2_TABLE_SIZE];
35
36
37static void
38init_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_OFFSET) / POW2_TABLE_SCALE);
43}
44
45
46/** log2(x), for x in [1.0, 2.0) */
47float log2_table[LOG2_TABLE_SIZE];
48
49
50static void
51init_log2_table(void)
52{
53   unsigned i;
54   for (i = 0; i < LOG2_TABLE_SIZE; i++)
55      log2_table[i] = (float) log2(1.0 + i * (1.0 / LOG2_TABLE_SCALE));
56}
57
58
59/**
60 * One time init for math utilities.
61 */
62void
63util_init_math(void)
64{
65   static boolean initialized = FALSE;
66   if (!initialized) {
67      init_pow2_table();
68      init_log2_table();
69      initialized = TRUE;
70   }
71}
72
73
74