ENH: Route PGRFSimulation logging through observer info() method

* Add defaulted virtual info() to ISimulationObserver — no-op by
  default so existing test doubles need no changes
* ConsoleObserver overrides info() to emit via spdlog (CLI output
  unchanged)
* FilterObserver overrides info() to forward through the simplnx
  IFilter::MessageHandler with Type::Info (no raw console lines
  from the DREAM3D-NX filter)
* Convert all five direct spdlog::info() calls in PGRFSimulation::run
  to observer->info() with nullptr guard; drop the redundant
  per-field spdlog line that duplicated the updateProgress message
* Remove unused #include <spdlog/spdlog.h> from PGRFSimulation.cpp

Signed-off-by: Michael Jackson <mike.jackson@bluequartz.net>

Author: imikejackson

src/LibMTRSim/ISimulationObserver.hpp

@@ -30,6 +30,12 @@ class LIBMTRSIM_EXPORT ISimulationObserver
   /// names it. `total <= 0` means "indeterminate".
   virtual void updateProgress(int64_t done, int64_t total, const std::string& message) = 0;
 
+  /// Emit an informational/diagnostic message (not progress). Default: no-op.
+  virtual void info(const std::string& message)
+  {
+    (void)message;
+  }
+
   /// Polled at checkpoints; returning true stops the simulation early.
   [[nodiscard]] virtual bool shouldCancel() const = 0;
 };

src/LibMTRSim/PGRFSimulation.cpp

@@ -9,7 +9,6 @@
 #include <algorithm>
 #include <cmath>
 #include <fmt/format.h>
-#include <spdlog/spdlog.h>
 #include <stdexcept>
 
 namespace mtrsim
@@ -55,12 +54,16 @@ PGRFResult PGRFSimulation::run(const SimulationParams& params, ISimulationObserv
     throw std::invalid_argument("PGRFSimulation: thetaList must have one row per latent Gaussian");
   }
 
-  spdlog::info("PGRFSimulation: grid {}x{}x{} = {} voxels, {} components, {} "
-               "latent fields",
-               nx, ny, nz, N, numComponents, numGaussians);
+  if(observer != nullptr)
+  {
+    observer->info(fmt::format("PGRFSimulation: grid {}x{}x{} = {} voxels, {} components, {} latent fields", nx, ny, nz, N, numComponents, numGaussians));
+  }
 
   // ── Select assignment-rule thresholds ────────────────────────────────────
-  spdlog::info("PGRFSimulation: selecting assignment rule thresholds...");
+  if(observer != nullptr)
+  {
+    observer->info("PGRFSimulation: selecting assignment rule thresholds...");
+  }
   AssignmentRule ar(m_Rng);
   const AssignmentRuleThresholds thresholds = ar.selectThresholds(params.volumeFractions);
 
@@ -84,7 +87,6 @@ PGRFResult PGRFSimulation::run(const SimulationParams& params, ISimulationObserv
       }
       observer->updateProgress(h, numGaussians, fmt::format("Simulating latent Gaussian field {}/{}", h + 1, numGaussians));
     }
-    spdlog::info("PGRFSimulation: simulating latent Gaussian Y{} ...", h + 1);
 
     const auto& thetaRow = params.thetaList[static_cast<std::size_t>(h)];
     if(thetaRow.size() < 3)
@@ -98,14 +100,20 @@ PGRFResult PGRFSimulation::run(const SimulationParams& params, ISimulationObserv
   }
 
   // ── Apply assignment rule ─────────────────────────────────────────────────
-  spdlog::info("PGRFSimulation: applying assignment rule...");
+  if(observer != nullptr)
+  {
+    observer->info("PGRFSimulation: applying assignment rule...");
+  }
   const Eigen::VectorXi mtrIndex = ar.evaluate(zAll, thresholds);
 
   // Log empirical volume fractions for verification
   for(int j = 1; j <= numComponents; ++j)
   {
     const int count = (mtrIndex.array() == j).count();
-    spdlog::info("  P{} empirical = {:.3f}  (target {:.3f})", j, static_cast<double>(count) / static_cast<double>(N), params.volumeFractions[static_cast<std::size_t>(j - 1)]);
+    if(observer != nullptr)
+    {
+      observer->info(fmt::format("  P{} empirical = {:.3f}  (target {:.3f})", j, static_cast<double>(count) / static_cast<double>(N), params.volumeFractions[static_cast<std::size_t>(j - 1)]));
+    }
   }
 
   return PGRFResult{mtrIndex, zAll};

src/LibMTRSim/SimulationObservers.hpp

@@ -43,6 +43,11 @@ class ConsoleObserver : public ISimulationObserver
       }
     }
   }
+  void info(const std::string& message) override
+  {
+    spdlog::info("{}", message);
+  }
+
   [[nodiscard]] bool shouldCancel() const override
   {
     return false;

src/MTRSim/Filters/Algorithms/MTRSim.cpp

@@ -39,6 +39,11 @@ class FilterObserver : public mtrsim::ISimulationObserver
     m_MessageHandler(IFilter::Message::Type::Progress, message, progress);
   }
 
+  void info(const std::string& message) override
+  {
+    m_MessageHandler(IFilter::Message::Type::Info, message);
+  }
+
   [[nodiscard]] bool shouldCancel() const override
   {
     return m_ShouldCancel.load();

src/MTRSim/Filters/MTRSimFilter.cpp

@@ -70,15 +70,6 @@ Parameters MTRSimFilter::parameters() const
 {
   Parameters params;
 
-  params.insertSeparator(Parameters::Separator{"Input ODF"});
-  params.insert(std::make_unique<GeometrySelectionParameter>(k_InputOdfGeometry_Key, "Input ODF Geometry", "Image Geometry holding the ODF (from the Read/Compute ODF filters).", DataPath{},
-                                                             GeometrySelectionParameter::AllowedTypes{IGeometry::Type::Image}));
-  params.insert(std::make_unique<MultiArraySelectionParameter>(k_OdfComponentArrays_Key, "ODF Component Arrays",
-                                                               "Ordered list of per-component ODF cell arrays. Order maps to Volume "
-                                                               "Fraction columns.",
-                                                               MultiArraySelectionParameter::ValueType{}, MultiArraySelectionParameter::AllowedTypes{IArray::ArrayType::DataArray},
-                                                               GetAllNumericTypes(), MultiArraySelectionParameter::AllowedComponentShapes{{1}}));
-
   params.insertSeparator(Parameters::Separator{"Configuration Source"});
   params.insertLinkableParameter(std::make_unique<BoolParameter>(k_UseConfigFile_Key, "Load Simulation Parameters from Config File",
                                                                  "When ON, read volume fractions, theta list, physical size/spacing, and seed from an MTRSim JSON config "
@@ -116,20 +107,31 @@ Parameters MTRSimFilter::parameters() const
   params.insert(std::make_unique<VectorFloat32Parameter>(k_PhysicalSpacing_Key, "Physical Spacing (microns)", "Voxel spacing X,Y,Z.", std::vector<float32>{0.02f, 0.02f, 0.02f},
                                                          std::vector<std::string>{"X", "Y", "Z"}));
 
+  params.insertSeparator(Parameters::Separator{"Input ODF"});
+  params.insert(std::make_unique<GeometrySelectionParameter>(k_InputOdfGeometry_Key, "Input ODF Geometry", "Image Geometry holding the ODF (from the Read/Compute ODF filters).", DataPath{},
+                                                             GeometrySelectionParameter::AllowedTypes{IGeometry::Type::Image}));
+  params.insert(std::make_unique<MultiArraySelectionParameter>(k_OdfComponentArrays_Key, "ODF Component Arrays",
+                                                               "Ordered list of per-component ODF cell arrays. Order maps to Volume "
+                                                               "Fraction columns.",
+                                                               MultiArraySelectionParameter::ValueType{}, MultiArraySelectionParameter::AllowedTypes{IArray::ArrayType::DataArray},
+                                                               GetAllNumericTypes(), MultiArraySelectionParameter::AllowedComponentShapes{{1}}));
+
   params.insertSeparator(Parameters::Separator{"Random Number Seed Parameters"});
   params.insertLinkableParameter(std::make_unique<BoolParameter>(k_UseSeed_Key, "Use Seed for Random Generation", "When true the user can supply a fixed seed.", false));
   params.insert(std::make_unique<NumberParameter<uint64>>(k_SeedValue_Key, "Seed Value", "The seed fed into the random generator.", std::mt19937::default_seed));
   params.insert(std::make_unique<DataObjectNameParameter>(k_SeedArrayName_Key, "Stored Seed Value Array Name", "Top-level array recording the seed used.", "MTRSim SeedValue"));
 
   params.insertSeparator(Parameters::Separator{"Output Data Object(s)"});
-  params.insertLinkableParameter(std::make_unique<BoolParameter>(k_GeneratePolarColoring_Key, "Generate Polar Coloring",
-                                                                 "Create a 3-component UInt8 RGB array using the MATLAB polar color "
-                                                                 "mapping.",
-                                                                 false));
+
   params.insert(std::make_unique<DataGroupCreationParameter>(k_OutputGeometry_Key, "Output Image Geometry", "Path of the new microstructure Image Geometry.", DataPath({"MTR Microstructure"})));
   params.insert(std::make_unique<DataObjectNameParameter>(k_CellAttrMatName_Key, "Cell Attribute Matrix Name", "Name of the created cell AttributeMatrix.", "Cell Data"));
   params.insert(std::make_unique<DataObjectNameParameter>(k_MtrIdsArrayName_Key, "MTR Ids Array Name", "Int32 per-voxel MTR component id (1-based).", "MTRIds"));
   params.insert(std::make_unique<DataObjectNameParameter>(k_EulersArrayName_Key, "Euler Angles Array Name", "Float32 3-component Bunge Euler angles [rad].", "Eulers"));
+
+  params.insertLinkableParameter(std::make_unique<BoolParameter>(k_GeneratePolarColoring_Key, "Generate Polar Coloring",
+                                                                 "Create a 3-component UInt8 RGB array using the MATLAB polar color "
+                                                                 "mapping.",
+                                                                 false));
   params.insert(std::make_unique<DataObjectNameParameter>(k_PolarColorsArrayName_Key, "Polar Colors Array Name", "UInt8 3-component RGB polar coloring.", "Polar Colors"));
 
   params.linkParameters(k_UseSeed_Key, k_SeedValue_Key, true);