Add JSON output for CSG objects (#1133)

* Add accessors to convex region
* Add Span IO
* Add accessors to CSG objects
* Add string output to transform type
* Add JSON pimpl helper
* Implement object output

src/corecel/cont/SpanIO.json.hh

@@ -0,0 +1,31 @@
+//----------------------------------*-C++-*----------------------------------//
+// Copyright 2024 UT-Battelle, LLC, and other Celeritas developers.
+// See the top-level COPYRIGHT file for details.
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+//---------------------------------------------------------------------------//
+//! \file corecel/cont/SpanIO.json.hh
+//---------------------------------------------------------------------------//
+#pragma once
+
+#include <nlohmann/json.hpp>
+
+#include "Span.hh"
+
+namespace celeritas
+{
+//---------------------------------------------------------------------------//
+/*!
+ * Write a span to a JSON file.
+ */
+template<class T, std::size_t N>
+void to_json(nlohmann::json& j, Span<T, N> const& value)
+{
+    j = nlohmann::json::array();
+    for (std::size_t i = 0; i != value.size(); ++i)
+    {
+        j.push_back(value[i]);
+    }
+}
+
+//---------------------------------------------------------------------------//
+}  // namespace celeritas

src/corecel/io/JsonPimpl.hh

@@ -8,6 +8,7 @@
 #pragma once
 
 #include "celeritas_config.h"
+#include "corecel/Assert.hh"
 
 #if CELERITAS_USE_JSON
 #    include <nlohmann/json.hpp>
@@ -42,5 +43,22 @@ struct JsonPimpl
 #endif
 };
 
+//---------------------------------------------------------------------------//
+/*!
+ * Helper function to write an object to JSON.
+ *
+ * This hides the "not configured" boilerplate.
+ */
+template<class T>
+void to_json_pimpl(JsonPimpl* jp, T const& self)
+{
+#if CELERITAS_USE_JSON
+    CELER_EXPECT(jp);
+    to_json(jp->obj, self);
+#else
+    CELER_NOT_CONFIGURED("JSON");
+#endif
+}
+
 //---------------------------------------------------------------------------//
 }  // namespace celeritas

src/orange/CMakeLists.txt

@@ -68,6 +68,7 @@ if(CELERITAS_USE_JSON)
     OrangeInputIO.json.cc
     detail/OrangeInputIOImpl.json.cc
     orangeinp/CsgTreeIO.json.cc
+    orangeinp/ObjectIO.json.cc
   )
   list(APPEND PRIVATE_DEPS nlohmann_json::nlohmann_json)
 endif()

src/orange/OrangeTypes.cc

@@ -107,6 +107,20 @@ char const* to_cstring(SurfaceType value)
     return to_cstring_impl(value);
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Get a string corresponding to a transform type.
+ */
+char const* to_cstring(TransformType value)
+{
+    static EnumStringMapper<TransformType> const to_cstring_impl{
+        "no_transformation",
+        "translation",
+        "transformation",
+    };
+    return to_cstring_impl(value);
+}
+
 //---------------------------------------------------------------------------//
 /*!
  * Get a printable character corresponding to a z ordering.

src/orange/OrangeTypes.hh

@@ -444,6 +444,9 @@ inline constexpr char to_char(Sense s)
 // Get a string corresponding to a surface type
 char const* to_cstring(SurfaceType);
 
+// Get a string corresponding to a transform type
+char const* to_cstring(TransformType);
+
 // Get a string corresponding to a surface state
 inline char const* to_cstring(SurfaceState s)
 {

src/orange/orangeinp/ConvexRegion.cc

@@ -11,6 +11,7 @@
 
 #include "corecel/Constants.hh"
 #include "corecel/cont/Range.hh"
+#include "corecel/io/JsonPimpl.hh"
 #include "geocel/BoundingBox.hh"
 #include "geocel/Types.hh"
 #include "orange/surf/ConeAligned.hh"
@@ -21,6 +22,10 @@
 
 #include "ConvexSurfaceBuilder.hh"
 
+#if CELERITAS_USE_JSON
+#    include "ObjectIO.json.hh"
+#endif
+
 namespace celeritas
 {
 namespace orangeinp
@@ -75,6 +80,15 @@ void Box::build(ConvexSurfaceBuilder& insert_surface) const
     insert_surface(Sense::inside, PlaneZ{hw_[Z]});
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Write output to the given JSON object.
+ */
+void Box::output(JsonPimpl* j) const
+{
+    to_json_pimpl(j, *this);
+}
+
 //---------------------------------------------------------------------------//
 // CONE
 //---------------------------------------------------------------------------//
@@ -167,6 +181,15 @@ void Cone::build(ConvexSurfaceBuilder& insert_surface) const
     insert_surface(Sense::outside, interior_bbox);
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Write output to the given JSON object.
+ */
+void Cone::output(JsonPimpl* j) const
+{
+    to_json_pimpl(j, *this);
+}
+
 //---------------------------------------------------------------------------//
 // CYLINDER
 //---------------------------------------------------------------------------//
@@ -191,6 +214,15 @@ void Cylinder::build(ConvexSurfaceBuilder& insert_surface) const
     insert_surface(CCylZ{radius_});
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Write output to the given JSON object.
+ */
+void Cylinder::output(JsonPimpl* j) const
+{
+    to_json_pimpl(j, *this);
+}
+
 //---------------------------------------------------------------------------//
 // ELLIPSOID
 //---------------------------------------------------------------------------//
@@ -249,6 +281,15 @@ void Ellipsoid::build(ConvexSurfaceBuilder& insert_surface) const
     insert_surface(Sense::outside, BBox{-inner_radii, inner_radii});
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Write output to the given JSON object.
+ */
+void Ellipsoid::output(JsonPimpl* j) const
+{
+    to_json_pimpl(j, *this);
+}
+
 //---------------------------------------------------------------------------//
 // PRISM
 //---------------------------------------------------------------------------//
@@ -319,6 +360,15 @@ void Prism::build(ConvexSurfaceBuilder& insert_surface) const
     insert_surface(Sense::outside, interior_bbox);
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Write output to the given JSON object.
+ */
+void Prism::output(JsonPimpl* j) const
+{
+    to_json_pimpl(j, *this);
+}
+
 //---------------------------------------------------------------------------//
 // SPHERE
 //---------------------------------------------------------------------------//
@@ -339,6 +389,15 @@ void Sphere::build(ConvexSurfaceBuilder& insert_surface) const
     insert_surface(SphereCentered{radius_});
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Write output to the given JSON object.
+ */
+void Sphere::output(JsonPimpl* j) const
+{
+    to_json_pimpl(j, *this);
+}
+
 //---------------------------------------------------------------------------//
 }  // namespace orangeinp
 }  // namespace celeritas

src/orange/orangeinp/ConvexRegion.hh

@@ -14,6 +14,8 @@
 
 namespace celeritas
 {
+struct JsonPimpl;
+
 namespace orangeinp
 {
 class ConvexSurfaceBuilder;
@@ -43,6 +45,9 @@ class ConvexRegionInterface
     //! Construct surfaces that are AND-ed into this region
     virtual void build(ConvexSurfaceBuilder&) const = 0;
 
+    //! Write the region to a JSON object
+    virtual void output(JsonPimpl*) const = 0;
+
   protected:
     //!@{
     //! Allow construction and assignment only through daughter classes
@@ -65,6 +70,14 @@ class Box final : public ConvexRegionInterface
     // Build surfaces
     void build(ConvexSurfaceBuilder&) const final;
 
+    // Output to JSON
+    void output(JsonPimpl*) const final;
+
+    //// ACCESSORS ////
+
+    //! Half-width for each axis
+    Real3 const& halfwidths() const { return hw_; }
+
   private:
     Real3 hw_;
 };
@@ -100,6 +113,17 @@ class Cone final : public ConvexRegionInterface
     // Build surfaces
     void build(ConvexSurfaceBuilder&) const final;
 
+    // Output to JSON
+    void output(JsonPimpl*) const final;
+
+    //// ACCESSORS ////
+
+    //! Lower and upper radii
+    Real2 const& radii() const { return radii_; }
+
+    //! Half-height along Z
+    real_type halfheight() const { return hh_; }
+
   private:
     Real2 radii_;
     real_type hh_;
@@ -118,6 +142,17 @@ class Cylinder final : public ConvexRegionInterface
     // Build surfaces
     void build(ConvexSurfaceBuilder&) const final;
 
+    // Output to JSON
+    void output(JsonPimpl*) const final;
+
+    //// ACCESSORS ////
+
+    //! Radius
+    real_type radius() const { return radius_; }
+
+    //! Half-height along Z
+    real_type halfheight() const { return hh_; }
+
   private:
     real_type radius_;
     real_type hh_;
@@ -136,6 +171,14 @@ class Ellipsoid final : public ConvexRegionInterface
     // Build surfaces
     void build(ConvexSurfaceBuilder&) const final;
 
+    // Output to JSON
+    void output(JsonPimpl*) const final;
+
+    //// ACCESSORS ////
+
+    //! Radius along each axis
+    Real3 const& radii() const { return radii_; }
+
   private:
     Real3 radii_;
 };
@@ -171,6 +214,20 @@ class Prism final : public ConvexRegionInterface
     // Build surfaces
     void build(ConvexSurfaceBuilder&) const final;
 
+    // Output to JSON
+    void output(JsonPimpl*) const final;
+
+    //// ACCESSORS ////
+
+    //! Number of sides
+    int num_sides() const { return num_sides_; }
+    //! Inner radius
+    real_type apothem() const { return apothem_; }
+    //! Half the Z height
+    real_type halfheight() const { return hh_; }
+    //! Rotation factor
+    real_type orientation() const { return orientation_; }
+
   private:
     // Number of sides
     int num_sides_;
@@ -198,6 +255,14 @@ class Sphere final : public ConvexRegionInterface
     // Build surfaces
     void build(ConvexSurfaceBuilder&) const final;
 
+    // Output to JSON
+    void output(JsonPimpl*) const final;
+
+    //// ACCESSORS ////
+
+    //! Radius
+    real_type radius() const { return radius_; }
+
   private:
     real_type radius_;
 };

src/orange/orangeinp/CsgObject.cc

@@ -9,9 +9,15 @@
 
 #include <utility>
 
+#include "corecel/io/JsonPimpl.hh"
+
 #include "detail/CsgUnitBuilder.hh"
 #include "detail/VolumeBuilder.hh"
 
+#if CELERITAS_USE_JSON
+#    include "ObjectIO.json.hh"
+#endif
+
 namespace celeritas
 {
 namespace orangeinp
@@ -49,6 +55,15 @@ NodeId NegatedObject::build(VolumeBuilder& vb) const
     return vb.insert_region(Label{label_}, Negated{daughter_id});
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Output to JSON.
+ */
+void NegatedObject::output(JsonPimpl* j) const
+{
+    to_json_pimpl(j, *this);
+}
+
 //---------------------------------------------------------------------------//
 // JOIN_OBJECTS
 //---------------------------------------------------------------------------//
@@ -91,6 +106,16 @@ NodeId JoinObjects<Op>::build(VolumeBuilder& vb) const
     return vb.insert_region(Label{label_}, Joined{op_token, std::move(nodes)});
 }
 
+//---------------------------------------------------------------------------//
+/*!
+ * Output to JSON.
+ */
+template<OperatorToken Op>
+void JoinObjects<Op>::output(JsonPimpl* j) const
+{
+    to_json_pimpl(j, *this);
+}
+
 //---------------------------------------------------------------------------//
 // FREE FUNCTIONS
 //---------------------------------------------------------------------------//