src/Sine.cxx

   1 /*
   2  * Sine.cxx
   3  * Daniel Nelson - 12/3/1
   4  *
   5  * Copyright (C) 2000  Daniel Nelson
   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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20  *
  21  * Daniel Nelson - aluminumangel.org
  22  * 174 W. 18th Ave.
  23  * Columbus, OH  43210
  24  *
  25  * Approximates sin(x) with a table and interpolation.
  26  */
  27
  28 #include "Sine.h"
  29
  30 #include "Game.h"
  31 #include "MetaState.h"
  32
  33 float Sine::table[GC_SINE_TABLE_LENGTH];
  34
  35 void Sine::initialize (   )
  36 {
  37   // currently only used in CM_SOLO mode
  38   if (!(MetaState::mode & CM_SOLO)) return;
  39
  40   for (int n = GC_SINE_TABLE_LENGTH; n--; ) {
  41     float x = n * GC_SINE_TABLE_STEP_WIDTH + GC_SINE_TABLE_LOWER_BOUND;
  42     table[n] = ::sin(x);
  43   }
  44 }