164 lines
5.2 KiB
C++
164 lines
5.2 KiB
C++
![]() |
/********************************************************************
|
||
|
KWin - the KDE window manager
|
||
|
This file is part of the KDE project.
|
||
|
|
||
|
Copyright 2017 Roman Gilg <subdiff@gmail.com>
|
||
|
|
||
|
This program is free software; you can redistribute it and/or modify
|
||
|
it under the terms of the GNU General Public License as published by
|
||
|
the Free Software Foundation; either version 2 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 General Public License for more details.
|
||
|
|
||
|
You should have received a copy of the GNU General Public License
|
||
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||
|
*********************************************************************/
|
||
|
#include "suncalc.h"
|
||
|
#include "constants.h"
|
||
|
|
||
|
#include <QDateTime>
|
||
|
#include <qmath.h>
|
||
|
|
||
|
namespace KWin {
|
||
|
namespace ColorCorrect {
|
||
|
|
||
|
#define TWILIGHT_NAUT -12.0
|
||
|
#define TWILIGHT_CIVIL -6.0
|
||
|
#define SUN_RISE_SET -0.833
|
||
|
#define SUN_HIGH 2.0
|
||
|
|
||
|
QPair<QTime, QTime> calculateSunTimings(QDate prompt, double latitude, double longitude, bool morning)
|
||
|
{
|
||
|
// calculations based on http://aa.quae.nl/en/reken/zonpositie.html
|
||
|
// accuracy: +/- 5min
|
||
|
|
||
|
// positioning
|
||
|
const double rad = M_PI / 180.;
|
||
|
const double earthObliquity = 23.4397; // epsilon
|
||
|
|
||
|
const double lat = latitude; // phi
|
||
|
const double lng = -longitude; // lw
|
||
|
|
||
|
// times
|
||
|
const double juPrompt = prompt.toJulianDay(); // J
|
||
|
const double ju2000 = 2451545.; // J2000
|
||
|
|
||
|
// geometry
|
||
|
auto mod360 = [](double number) -> double {
|
||
|
return std::fmod(number, 360.);
|
||
|
};
|
||
|
|
||
|
auto sin = [&rad](double angle) -> double {
|
||
|
return std::sin(angle * rad);
|
||
|
};
|
||
|
auto cos = [&rad](double angle) -> double {
|
||
|
return std::cos(angle * rad);
|
||
|
};
|
||
|
auto asin = [&rad](double val) -> double {
|
||
|
return std::asin(val) / rad;
|
||
|
};
|
||
|
auto acos = [&rad](double val) -> double {
|
||
|
return std::acos(val) / rad;
|
||
|
};
|
||
|
|
||
|
auto anomaly = [&](const double date) -> double { // M
|
||
|
return mod360(357.5291 + 0.98560028 * (date - ju2000));
|
||
|
};
|
||
|
|
||
|
auto center = [&sin](double anomaly) -> double { // C
|
||
|
return 1.9148 * sin(anomaly) + 0.02 * sin(2 * anomaly) + 0.0003 * sin(3 * anomaly);
|
||
|
};
|
||
|
|
||
|
auto ecliptLngMean = [](double anom) -> double { // Mean ecliptical longitude L_sun = Mean Anomaly + Perihelion + 180°
|
||
|
return anom + 282.9372; // anom + 102.9372 + 180°
|
||
|
};
|
||
|
|
||
|
auto ecliptLng = [&](double anom) -> double { // lambda = L_sun + C
|
||
|
return ecliptLngMean(anom) + center(anom);
|
||
|
};
|
||
|
|
||
|
auto declination = [&](const double date) -> double { // delta
|
||
|
const double anom = anomaly(date);
|
||
|
const double eclLng = ecliptLng(anom);
|
||
|
|
||
|
return mod360(asin(sin(earthObliquity) * sin(eclLng)));
|
||
|
};
|
||
|
|
||
|
// sun hour angle at specific angle
|
||
|
auto hourAngle = [&](const double date, double angle) -> double { // H_t
|
||
|
const double decl = declination(date);
|
||
|
const double ret0 = (sin(angle) - sin(lat) * sin(decl)) / (cos(lat) * cos(decl));
|
||
|
|
||
|
double ret = mod360(acos( ret0 ));
|
||
|
if (180. < ret) {
|
||
|
ret = ret - 360.;
|
||
|
}
|
||
|
return ret;
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* Sun positions
|
||
|
*/
|
||
|
|
||
|
// transit is at noon
|
||
|
auto getTransit = [&](const double date) -> double { // Jtransit
|
||
|
const double juMeanSolTime = juPrompt - ju2000 - 0.0009 - lng / 360.; // n_x = J - J_2000 - J_0 - l_w / 360°
|
||
|
const double juTrEstimate = date + qRound64(juMeanSolTime) - juMeanSolTime; // J_x = J + n - n_x
|
||
|
const double anom = anomaly(juTrEstimate); // M
|
||
|
const double eclLngM = ecliptLngMean(anom); // L_sun
|
||
|
|
||
|
return juTrEstimate + 0.0053 * sin(anom) - 0.0068 * sin(2 * eclLngM);
|
||
|
};
|
||
|
|
||
|
auto getSunMorning = [&hourAngle](const double angle, const double transit) -> double {
|
||
|
return transit - hourAngle(transit, angle) / 360.;
|
||
|
};
|
||
|
|
||
|
auto getSunEvening = [&hourAngle](const double angle, const double transit) -> double {
|
||
|
return transit + hourAngle(transit, angle) / 360.;
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* Begin calculations
|
||
|
*/
|
||
|
|
||
|
// noon - sun at the highest point
|
||
|
const double juNoon = getTransit(juPrompt);
|
||
|
|
||
|
double begin, end;
|
||
|
if (morning) {
|
||
|
begin = getSunMorning(TWILIGHT_CIVIL, juNoon);
|
||
|
end = getSunMorning(SUN_HIGH, juNoon);
|
||
|
} else {
|
||
|
begin = getSunEvening(SUN_HIGH, juNoon);
|
||
|
end = getSunEvening(TWILIGHT_CIVIL, juNoon);
|
||
|
}
|
||
|
// transform to QDateTime
|
||
|
begin += 0.5;
|
||
|
end += 0.5;
|
||
|
|
||
|
QTime timeBegin, timeEnd;
|
||
|
|
||
|
if (std::isnan(begin)) {
|
||
|
timeBegin = QTime();
|
||
|
} else {
|
||
|
double timePart = begin - (int)begin;
|
||
|
timeBegin = QTime::fromMSecsSinceStartOfDay((int)( timePart * MSC_DAY ));
|
||
|
}
|
||
|
if (std::isnan(end)) {
|
||
|
timeEnd = QTime();
|
||
|
} else {
|
||
|
double timePart = end - (int)end;
|
||
|
timeEnd = QTime::fromMSecsSinceStartOfDay((int)( timePart * MSC_DAY ));
|
||
|
}
|
||
|
|
||
|
return QPair<QTime,QTime> (timeBegin, timeEnd);
|
||
|
}
|
||
|
|
||
|
}
|
||
|
}
|