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