Added two static functions to test whether or not a geometrical configuration...

 Added two static functions to test whether or not a geometrical configuration is above the hemisphere
 Added a new unit test for the params::is_above_hemisphere static function

sources/core/params.cpp

@@ -831,3 +831,21 @@ void params::print_input_params()
 		std::cout << it->second.info << std::endl;
 	}
 }
+
+
+bool 
+params::is_above_hemisphere( double* const invec, params::input in_param_type )
+{
+	vec input_in_cartesian(6);
+
+	params::convert(invec, in_param_type, params::CARTESIAN, &input_in_cartesian[0]);
+
+	return input_in_cartesian[2] >= 0.0  && input_in_cartesian[5] >= 0.0;
+
+}
+
+
+
+
+
+

sources/core/params.h

@@ -415,6 +415,17 @@ class params
 
       static void print_input_params();
 
+      //! \brief Check whether or not a (light,view) configuration is above the hemisphere
+      //! \return true if both vectors (light and view) are above and false otherwise
+      //! \remark the function returns true also for grazing, tangential configuration 
+      //! (i.e., where light dot normal == 0 or view dot normal == 0)
+      static bool is_above_hemisphere( double* invec,         params::input intype );
+
+      static bool inline is_below_hemisphere( double* invec,         params::input intype )
+      {
+        return ! is_above_hemisphere(invec, intype);
+      }
+
 };
 
 /*! \brief A parameters object. Allow to define function object (either data

sources/tests/SConscript

@@ -177,6 +177,7 @@ CXX_TESTS = [ 'core/half-test-1.cpp',
               'core/half-test-3.cpp',
               'core/half-test-4.cpp',
               'core/params-test-1.cpp',
+              'core/params-test-2.cpp',
               'core/data-io.cpp',
               'core/nonlinear-fit.cpp' ]
 

sources/tests/core/params-test-2.cpp

+/* ALTA --- Analysis of Bidirectional Reflectance Distribution Functions
+
+   Copyright (C) 2016 CNRS, romain.pacanowski@institutoptique.fr
+
+
+   This file is part of ALTA.
+
+   This Source Code Form is subject to the terms of the Mozilla Public
+   License, v. 2.0.  If a copy of the MPL was not distributed with this
+   file, You can obtain one at http://mozilla.org/MPL/2.0/.  */
+
+// ALTA includes
+#include <core/params.h>
+#include <tests.h>
+
+using namespace alta;
+using namespace alta::tests;
+
+#include <cmath>
+#include <cstdlib>
+#include <iostream>
+#include <random>
+
+typedef std::mt19937_64 GENERATOR_TYPE;
+
+/* Test different configurations for the Half / Cartesian parametrization.  */
+int main(int argc, char** argv) 
+{
+
+  unsigned int const NB_TESTS = 1000;
+  unsigned int nb_pass = 0;
+  // Number of failed tests
+  unsigned int nb_fail = 0;
+
+  // Testing is Above with Cartesians Configurations
+  std::uniform_real_distribution<> distribution(-1.0, 1.0);
+  GENERATOR_TYPE                      generator( time(NULL) );
+
+  vec input_lv(6);
+  for (unsigned int i = 0; i < NB_TESTS; ++i)
+  {
+     double const l_x =  distribution( generator );
+     double const l_y = distribution( generator );
+     double const l_z = std::sqrt(std::max( 1.0 - l_x*l_x - l_y*l_y, 0.0) );
+
+     double const v_x = distribution( generator );
+     double const v_y = distribution( generator );
+     double const v_z = std::sqrt( std::max( 1.0 - v_x*v_x - v_y*v_y, 0.0) );
+
+     input_lv(0) = l_x; input_lv(1) = l_y; input_lv(2) = l_z;
+     input_lv(3) = v_x; input_lv(4) = v_y; input_lv(5) = v_z;
+
+     if(  params::is_above_hemisphere( &input_lv[0], params::CARTESIAN ) )
+     {
+        nb_pass++;
+     }
+     else
+     {
+        nb_fail++;
+     }
+  }
+
+
+  if(nb_fail > 0) {
+      std::cerr << "<<ERROR>> " << nb_fail << " out of " << NB_TESTS
+                << " configurations fail the test is_above_hemisphere "
+                << std::endl;
+  }
+
+  return nb_fail > 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}