SunLight

SunLight is a C++ class library that calculates various sunrise and sunset phases based on date, latitude, and longitude. Its implementation is based on the NOAA Solar Calculator.

Features

Calculate the exact time for:

• Sunrise: When the upper edge of the Sun appears over the eastern horizon.
• Sunset: When the upper edge of the Sun disappears below the horizon.
• Civil Dawn/Dusk: Sun is 6 degrees below the horizon. Objects are distinguishable.
• Nautical Dawn/Dusk: Sun is 12 degrees below the horizon. Horizon is visible.
• Astronomical Dawn/Dusk: Sun is 18 degrees below the horizon. Sky is no longer completely dark.
• Golden Hour: Soft, warm light when the sun is close to the horizon.

Installation

CMake

You can include SunLight in your project using CMake.

1. Clone the repository or add it as a submodule.
2. Add the following to your CMakeLists.txt:

add_subdirectory(SunLight)
target_link_libraries(YourTarget PRIVATE SunLight)

Usage

Here is a simple example of how to use the SunLight library:

#include <iostream>
#include <ctime>
#include "SunLight.h"

int main() {
    // Stockholm, Sweden
    double latitude  = 59.370272;
    double longitude = 18.000767;
    time_t now       = time(NULL);

    SunLight sunLight(Date(now), latitude, longitude);

    time_t sunrise = sunLight.sunrise();
    time_t sunset  = sunLight.sunset();

    std::cout << "Sunrise: " << asctime(gmtime(&sunrise));
    std::cout << "Sunset:  " << asctime(gmtime(&sunset));

    return 0;
}

Testing

Install Google Test (GTest)

sudo apt-get install libgtest-dev
cd /usr/src/gtest
sudo cmake .
sudo make
sudo cp lib/*.a /usr/lib

Running Tests

1. Build with tests enabled:

cd build
cmake -DCMAKE_BUILD_TYPE=Release -Dmake_tests=ON ..
make

2. Run the tests:

./Tests/SunLight_tests

Reference

• NOAA Solar Calculator

Credits

This library is strongly influenced by the JavaScript library solar-calc.

License

This project is licensed under the MIT License - see the LICENSE file for details.