minetest/src/daynightratio.h
2013-02-24 20:15:24 +01:00

70 lines
1.8 KiB
C

/*
Minetest
Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef DAYNIGHTRATIO_HEADER
#define DAYNIGHTRATIO_HEADER
inline u32 time_to_daynight_ratio(float time_of_day, bool smooth)
{
float t = time_of_day;
if(t < 0)
t += ((int)(-t)/24000)*24000;
if(t >= 24000)
t -= ((int)(t)/24000)*24000;
if(t > 12000)
t = 24000 - t;
float values[][2] = {
{4250+125, 150},
{4500+125, 150},
{4750+125, 250},
{5000+125, 350},
{5250+125, 500},
{5500+125, 675},
{5750+125, 875},
{6000+125, 1000},
{6250+125, 1000},
};
if(!smooth){
float lastt = values[0][0];
for(u32 i=1; i<sizeof(values)/sizeof(*values); i++){
float t0 = values[i][0];
float switch_t = (t0 + lastt) / 2;
lastt = t0;
if(switch_t <= t)
continue;
return values[i][1];
}
return 1000;
} else {
for(u32 i=0; i<sizeof(values)/sizeof(*values); i++){
if(values[i][0] <= t)
continue;
if(i == 0)
return values[i][1];
float td0 = values[i][0] - values[i-1][0];
float f = (t - values[i-1][0]) / td0;
return f * values[i][1] + (1.0 - f) * values[i-1][1];
}
return 1000;
}
}
#endif