/**************************************************************************
*
* Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
#include "util/u_math.h"
/** 2^x, for x in [-1.0, 1.0) */
float pow2_table[POW2_TABLE_SIZE];
static void
init_pow2_table(void)
{
int i;
for (i = 0; i < POW2_TABLE_SIZE; i++)
pow2_table
[i
] = (float) pow(2.0, (i
- POW2_TABLE_OFFSET
) / POW2_TABLE_SCALE
);}
/** log2(x), for x in [1.0, 2.0) */
float log2_table[LOG2_TABLE_SIZE];
static void
init_log2_table(void)
{
unsigned i;
for (i = 0; i < LOG2_TABLE_SIZE; i++)
log2_table[i] = (float) log2(1.0 + i * (1.0 / LOG2_TABLE_SCALE));
}
/**
* One time init for math utilities.
*/
void
util_init_math(void)
{
static boolean initialized = FALSE;
if (!initialized) {
init_pow2_table();
init_log2_table();
initialized = TRUE;
}
}