OccultationModel.h

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/*
Occultation model header file

Author: Alex Jackson
*/
/*
Metadata for MS GUI:
imdata = {"displayname" : "Occultation",
          "exclude" : False,
          "category" : "Environment"
}
aliases = {"r_s" : "Source Object Radius",
           "r_oc" : "Occulting Object Radius",
           "pos_ob__f" : "Observer Position",
           "pos_oc__f" : "Occulting Object Position",
           "pos_s__f" : "Source Position",
           "occ_frac" : "Visibility Fraction",
}
*/

#ifndef MODELS_ENVIRONMENT_OCCULTATION_MODEL_H
#define MODELS_ENVIRONMENT_OCCULTATION_MODEL_H

#include "simulation/Model.h"
#include "frames/Frame.h"
#include "frames/Node.h"
#include "frames/frameutils.h"
#include "constants/planetdefaults.h"


namespace warptwin {


    /**
     * @brief   Occultation model using spherical representations of objects
     * 
     * This model calculates the occultation fraction of a source from the
     * perspective of an observer using spherical representations of the
     * occulting object and source.
    */
   MODEL(OccultationModel)
    public:
        // Model params
        //         NAME                     TYPE                    DEFAULT VALUE
        START_PARAMS
            /* This is the radius of the source object. If the object is not spherical,
             * a representative radius should be used. The default is zero radius (point)
             */
            SIGNAL(r_s,                     double,                 0.0)
            /* This is the radius of the occulting object. If the object is not spherical,
             * a representative radius should be used. The default is zero radius (point)
             */
            SIGNAL(r_oc,                    double,                 0.0)
        END_PARAMS

        // Model inputs
        //         NAME                     TYPE                    DEFAULT VALUE
        START_INPUTS
            /** The position of the observer in the reference frame f */
            SIGNAL(pos_ob__f,               CartesianVector3,      CartesianVector3({0.0, 0.0, 0.0}))
            /** The position of the occulting object in the reference frame f*/
            SIGNAL(pos_oc__f,               CartesianVector3,      CartesianVector3({0.0, 0.0, 0.0}))
            /** The position of the source object in the reference frame f*/
            SIGNAL(pos_s__f,                CartesianVector3,      CartesianVector3({0.0, 0.0, 0.0}))
        END_INPUTS

        // Model outputs
        //         NAME                     TYPE                    DEFAULT VALUE
        START_OUTPUTS
            /** Fraction of two spherical representations of objects that are visible from the point
             * of view of the observer. 0 is fully occulted, 1 is not occulted, 0-1 is 
             * visible fraction of observed object. */
            SIGNAL(occ_frac,                double,                 1.0)
        END_OUTPUTS

    protected:
        int16 execute() override; 

        // Temporary vectors and variables to carry out our calculations
        double _a_i;
        double _d;
        double _d_1;
        double _d_2;
        double _d_e;
        double _d_i;
        double _d_o;
        double _theta;
        double _tmp;
        double _tmp1;
        double _tmp2;
        double _tmp3;
        double _tmp4;
        double _tmp5;
        CartesianVector3 _s_ob_vec;
        CartesianVector3 _tmpvec;
    };

}

#endif