deprecated / bimsim

  #include "montecarlo.h"

  #include "rts/math/quaternion.h"
  #include "rts/math/matrix.h"

  #include <iostream>
  #include <stdlib.h>
  using namespace std;
  
  void mcSampleNA(bsVector* samples, int N, bsVector k, ptype NAin, ptype NAout)
  {
      /*Create Monte-Carlo samples of a cassegrain objective by performing uniform sampling
          of a sphere and projecting these samples onto an inscribed sphere.
  
          samples = rtsPointer to sample vectors specified as normalized cartesian coordinates
          N       = number of samples
  		kSph	= incident light direction in spherical coordinates
          NAin    = internal obscuration NA
          NAout   = outer cassegrain NA
      */
  
  	//get the axis of rotation for transforming (0, 0, 1) to k
  	//k = -k;
  	ptype cos_angle = k.dot(bsVector(0, 0, 1));

  	rts::matrix<ptype, 3> rotation;

  	if(cos_angle != 1.0)
  	{
  		bsVector axis = bsVector(0, 0, 1).cross(k).norm();
  
  		ptype angle = acos(cos_angle);

  		rts::quaternion<ptype> quat;

  		quat.CreateRotation(angle, axis);

  		rotation = quat.toMatrix3();

  	}
  
      //find the phi values associated with the cassegrain ring
      ptype inPhi = asin(NAin);
      ptype outPhi = asin(NAout);
  

      //calculate the z-values associated with these angles
      ptype inZ = cos(inPhi);
      ptype outZ = cos(outPhi);
  
      ptype rangeZ = inZ - outZ;
  

      //draw a distribution of random phi, z values
      ptype z, phi, theta;
      for(int i=0; i<N; i++)
      {

          z = ((ptype)rand() / (ptype)RAND_MAX) * rangeZ + outZ;
          theta = ((ptype)rand() / (ptype)RAND_MAX) * 2 * (ptype)PI;

  
          //calculate theta
          phi = acos(z);
  
          //compute and store cartesian coordinates

  		bsVector spherical(1, theta, phi);
  		bsVector cart = spherical.sph2cart();
          samples[i] = rotation * cart;
      }
  
  
  
  
  }