Move MaterialFilter to C++

include/openmc/material.h

@@ -24,7 +24,7 @@ extern std::unordered_map<int32_t, int32_t> material_map;
 class Material
 {
 public:
-  int32_t id; //!< Unique ID
+  int32_t id_; //!< Unique ID
   double volume_ {-1.0}; //!< Volume in [cm^3]
 
   //! \brief Default temperature for cells containing this material.

include/openmc/tallies/tally_filter_material.h

@@ -0,0 +1,81 @@
+#ifndef OPENMC_TALLY_FILTER_MATERIAL_H
+#define OPENMC_TALLY_FILTER_MATERIAL_H
+
+#include <sstream>
+#include <unordered_map>
+#include <vector>
+
+#include "openmc/error.h"
+#include "openmc/material.h"
+#include "openmc/tallies/tally_filter.h"
+
+
+namespace openmc {
+
+class MaterialFilter : public TallyFilter
+{
+public:
+  virtual std::string type() const override {return "material";}
+
+  virtual ~MaterialFilter() override = default;
+
+  virtual void
+  from_xml(pugi::xml_node node) override
+  {
+    materials_ = get_node_array<int32_t>(node, "bins");
+    n_bins_ = materials_.size();
+  }
+
+  virtual void
+  initialize() override
+  {
+    for (auto& m : materials_) {
+      auto search = material_map.find(m);
+      if (search != material_map.end()) {
+        m = search->second;
+      } else {
+        std::stringstream err_msg;
+        err_msg << "Could not find material " << m
+                << " specified on tally filter.";
+        fatal_error(err_msg);
+      }
+    }
+
+    for (int i = 0; i < materials_.size(); i++) {
+      map_[materials_[i]] = i;
+    }
+  }
+
+  virtual void
+  get_all_bins(Particle* p, int estimator, TallyFilterMatch& match)
+  const override
+  {
+    auto search = map_.find(p->material - 1);
+    if (search != map_.end()) {
+      // TODO: off-by-one
+      match.bins.push_back(search->second + 1);
+      match.weights.push_back(1);
+    }
+  }
+
+  virtual void
+  to_statepoint(hid_t filter_group) const override
+  {
+    TallyFilter::to_statepoint(filter_group);
+    std::vector<int32_t> material_ids;
+    for (auto c : materials_) material_ids.push_back(materials[c]->id_);
+    write_dataset(filter_group, "bins", material_ids);
+  }
+
+  virtual std::string
+  text_label(int bin) const override
+  {
+    return "Material " + std::to_string(materials[materials_[bin-1]]->id_);
+  }
+
+  std::vector<int32_t> materials_;
+  std::unordered_map<int32_t, int> map_;
+};
+
+} // namespace openmc
+#endif // OPENMC_TALLY_FILTER_MATERIAL_H