const-correctness, changed a few names, renamed file

examples/environment_example.cpp → examples/environment.cpp

@@ -16,56 +16,62 @@ using namespace corsika;
 
 // Example to show how to construct an environment in CORSIKA
 
-// MediumType is constructed via "mixin inheritance"
+// MyMediumInterface is constructed via "mixin inheritance"
 // Here, we construct our base class with IMediumModel and IMediumPropertyModel:
 // the former allow us define a density profile and nuclear composite,
 // the later is used to determine energy losses parameters.
-using IMediumType = IMediumPropertyModel<IMediumModel>;
+using MyMediumInterface = IMediumPropertyModel<IMediumModel>;
 
-using EnvType = Environment<IMediumType>;
+using MyEnvType = Environment<MyMediumInterface>;
 
 int main() {
-  // define the environment and universe
-  EnvType env;
-  VolumeTreeNode<IMediumType>* universe = env.getUniverse().get();
+  // create environment and universe, empty so far
+  MyEnvType env;
 
-  // create a geometry object: a sphere with radius of 1000m
+  // create a geometry object: a sphere with radius of 1000 m
   CoordinateSystemPtr const& rootCS = env.getCoordinateSystem();
   Point const center{rootCS, 0_m, 0_m, 0_m};
-  LengthType radius = 1000_m;
+  LengthType const radius = 1000_m;
   auto sphere = std::make_unique<Sphere>(center, radius);
 
   // create node from geometry object
-  auto node = std::make_unique<VolumeTreeNode<IMediumType>>(std::move(sphere));
+  auto node = std::make_unique<VolumeTreeNode<MyMediumInterface>>(std::move(sphere));
 
   // set medium properties to our node, say it is water
-  auto nuc_comp = NuclearComposition({{Code::Hydrogen, Code::Oxygen}, {0.11, 0.89}});
-  MassDensityType density = 1_g / (1_cm * 1_cm * 1_cm);
-  auto medium = std::make_shared<MediumPropertyModel<HomogeneousMedium<IMediumType>>>(
-      Medium::WaterLiquid, density, nuc_comp);
+  NuclearComposition const nucl_comp{{Code::Hydrogen, Code::Oxygen}, {0.11, 0.89}};
+  MassDensityType const density = 1_g / (1_cm * 1_cm * 1_cm);
+
+  // create concrete implementation of MyMediumInterface by combining parts that
+  // implement the corresponding interfaces. HomogeneousMedium implements IMediumModel,
+  // MediumPropertyModel implements IMediumPropertyModel.
+  auto const medium =
+      std::make_shared<MediumPropertyModel<HomogeneousMedium<MyMediumInterface>>>(
+          Medium::WaterLiquid, density, nucl_comp);
   node->setModelProperties(medium);
 
   // put our node into universe
   // node: this has to be down after setting node model properties, since
   // std::move will make our previous defined node, which is a unique pointer
   // un-referencable in the context
+  VolumeTreeNode<MyMediumInterface>* const universe = env.getUniverse().get();
   universe->addChild(std::move(node));
 
   // example to explore the media properties of the node
-  for (LengthType h = 0_m; h < radius; h += 100_m) {
+  for (auto h = 0_m; h < radius; h += 100_m) {
     Point const ptest{rootCS, 0_m, 0_m, h};
-    IMediumType const& media_prop_ =
+    MyMediumInterface const& media_prop =
         env.getUniverse()->getContainingNode(ptest)->getModelProperties();
-    MassDensityType rho_ = media_prop_.getMassDensity(ptest);
-    NuclearComposition nuc_comp_ = media_prop_.getNuclearComposition();
-    std::vector<Code> nucs_ = nuc_comp_.getComponents();
-    std::vector<double> fracs_ = nuc_comp_.getFractions();
+    MassDensityType const rho = media_prop.getMassDensity(ptest);
+    NuclearComposition const& nuc_comp = media_prop.getNuclearComposition();
+    std::vector<Code> const& nuclei = nuc_comp.getComponents();
+    std::vector<double> const& fractions = nuc_comp.getFractions();
     CORSIKA_LOG_INFO(
-        "radius: {:.2f} m, density: {:.2f} g/cm^3, nucs: ({:d}, {:d}), fracs: ({:.2f}, "
+        "radius: {:.2f} m, density: {:.2f} g/cm^3, nuclei: ({:d}, {:d}), fractions: "
+        "({:.2f}, "
         "{:.2f})",
-        h / 1_m, rho_ / 1_g * (1_cm * 1_cm * 1_cm), get_PDG(nucs_[0]), get_PDG(nucs_[1]),
-        fracs_[0], fracs_[1]);
+        h / 1_m, rho / (1_g / static_pow<3>(1_cm)), get_PDG(nuclei.at(0)),
+        get_PDG(nuclei.at(1)), fractions.at(0), fractions.at(1));
   }
 
   return 0;
-}
\ No newline at end of file
+}