source: libcaca/trunk/libee/math.c @ 147

Last change on this file since 147 was 147, checked in by Sam Hocevar, 18 years ago
  • libee/graphics.c: + Moved ee_putstr() and ee_putchar() in here.
  • libee/ee.h: + Got rid of ee_goto(). + Moved <slang.h> or <curses.h> into libee.
  • Replaced ee_goto()/ee_putstr() pairs with ee_putstr().
  • Ditto for ee_putchar().
  • Property svn:keywords set to Id
File size: 1.4 KB
Line 
1/*
2 *   libee         ASCII-Art library
3 *   Copyright (c) 2002, 2003 Sam Hocevar <sam@zoy.org>
4 *                 All Rights Reserved
5 *
6 *   $Id: math.c 147 2003-11-10 23:38:50Z sam $
7 *
8 *   This program is free software; you can redistribute it and/or modify
9 *   it under the terms of the GNU General Public License as published by
10 *   the Free Software Foundation; either version 2 of the License, or
11 *   (at your option) any later version.
12 *
13 *   This program is distributed in the hope that it will be useful,
14 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *   GNU General Public License for more details.
17 *
18 *   You should have received a copy of the GNU General Public License
19 *   along with this program; if not, write to the Free Software
20 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23#include "config.h"
24
25#ifdef USE_SLANG
26#   include <slang.h>
27#elif USE_NCURSES
28#   include <curses.h>
29#endif
30
31#include <stdlib.h>
32
33#include "ee.h"
34
35int ee_rand(int min, int max)
36{
37    return min + (int)((1.0*(max-min+1)) * rand() / (RAND_MAX+1.0));
38}
39
40int ee_sqrt(int a)
41{
42    int x;
43
44    if(a <= 0)
45    {
46        return 0;
47    }
48
49    x = a > 100000 ? 1000 : a > 1000 ? 100 : a > 10 ? 10 : 1;
50
51    /* Newton's method. Three iterations would be more than enough. */
52    x = (x * x + a) / x / 2;
53    x = (x * x + a) / x / 2;
54    x = (x * x + a) / x / 2;
55    x = (x * x + a) / x / 2;
56
57    return x;
58}
59
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