util.c

   1
   2 /**
   3  *
   4  * Tennix! SDL Port
   5  * Copyright (C) 2003, 2007, 2008, 2009 Thomas Perl <thp@thpinfo.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  20  * MA  02110-1301, USA.
  21  *
  22  **/
  23
  24 #include "tennix.h"
  25 #include "util.h"
  26
  27 #include <time.h>
  28 #include <assert.h>
  29
  30 void day_night(unsigned int width, unsigned int* start, unsigned int* end)
  31 {
  32     time_t t = time(NULL);
  33     unsigned int offset = 60; /* set this so the day/night fits for London */
  34
  35     assert(start != NULL);
  36     assert(end != NULL);
  37
  38     *start = (unsigned int)(offset - (t/60)*width/(60*24)) % width;
  39     *end = (unsigned int)(*start + width/2) % width;
  40 }
  41
  42 /**
  43  * The following functions are implemented, because we had problems
  44  * with the math library functions on some target platforms. If these
  45  * problems are fixed, and Tennix runs with the fminf/fmaxf/fabsf
  46  * functions, these can be removed and the calls replaced.
  47  **/
  48
  49 float minf(float a, float b)
  50 {
  51     if (a < b) {
  52         return a;
  53     } else {
  54         return b;
  55     }
  56 }
  57
  58 float maxf(float a, float b)
  59 {
  60     if (a > b) {
  61         return a;
  62     } else {
  63         return b;
  64     }
  65 }
  66
  67 float absf(float a)
  68 {
  69     if (a >= 0.0) {
  70         return a;
  71     } else {
  72         return -a;
  73     }
  74 }
  75