Line data    Source code

       1             : /*
       2             : Minetest
       3             : Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
       4             : 
       5             : This program is free software; you can redistribute it and/or modify
       6             : it under the terms of the GNU Lesser General Public License as published by
       7             : the Free Software Foundation; either version 2.1 of the License, or
       8             : (at your option) any later version.
       9             : 
      10             : This program is distributed in the hope that it will be useful,
      11             : but WITHOUT ANY WARRANTY; without even the implied warranty of
      12             : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      13             : GNU Lesser General Public License for more details.
      14             : 
      15             : You should have received a copy of the GNU Lesser General Public License along
      16             : with this program; if not, write to the Free Software Foundation, Inc.,
      17             : 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
      18             : */
      19             : 
      20             : #ifndef DAYNIGHTRATIO_HEADER
      21             : #define DAYNIGHTRATIO_HEADER
      22             : 
      23     1460846 : inline u32 time_to_daynight_ratio(float time_of_day, bool smooth)
      24             : {
      25     1460846 :         float t = time_of_day;
      26     1460846 :         if(t < 0)
      27           0 :                 t += ((int)(-t)/24000)*24000;
      28     1460846 :         if(t >= 24000)
      29           0 :                 t -= ((int)(t)/24000)*24000;
      30     1460846 :         if(t > 12000)
      31           0 :                 t = 24000 - t;
      32             :         float values[][2] = {
      33             :                 {4250+125, 150},
      34             :                 {4500+125, 150},
      35             :                 {4750+125, 250},
      36             :                 {5000+125, 350},
      37             :                 {5250+125, 500},
      38             :                 {5500+125, 675},
      39             :                 {5750+125, 875},
      40             :                 {6000+125, 1000},
      41             :                 {6250+125, 1000},
      42     1460846 :         };
      43     1460846 :         if(!smooth){
      44           0 :                 float lastt = values[0][0];
      45           0 :                 for(u32 i=1; i<sizeof(values)/sizeof(*values); i++){
      46           0 :                         float t0 = values[i][0];
      47           0 :                         float switch_t = (t0 + lastt) / 2;
      48           0 :                         lastt = t0;
      49           0 :                         if(switch_t <= t)
      50           0 :                                 continue;
      51           0 :                         return values[i][1];
      52             :                 }
      53           0 :                 return 1000;
      54             :         } else {
      55    14608460 :                 for(u32 i=0; i<sizeof(values)/sizeof(*values); i++){
      56    13147614 :                         if(values[i][0] <= t)
      57    13147614 :                                 continue;
      58           0 :                         if(i == 0)
      59           0 :                                 return values[i][1];
      60           0 :                         float td0 = values[i][0] - values[i-1][0];
      61           0 :                         float f = (t - values[i-1][0]) / td0;
      62           0 :                         return f * values[i][1] + (1.0 - f) * values[i-1][1];
      63             :                 }
      64     1460846 :                 return 1000;
      65             :         }
      66             : }
      67             : 
      68             : #endif
      69             :