extract costly construction in tight loop

src/simplnx/Utilities/Math/GeometryMath.cpp

@@ -54,9 +54,17 @@ BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfVertices(INodeGeometry0D
   return {ll, ur}; // should be valid
 }
 
-BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfFace(const detail::GeometryStoreCache& cache, const nx::core::TriangleGeom& triangleGeom, int32 faceId)
+BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfFace(const detail::GeometryStoreCache& cache, const nx::core::TriangleGeom& triangleGeom, int32 faceId, std::vector<usize>& verts)
 {
-  std::array<Point3Df, 3> points = GeometryMath::detail::GetFaceCoordinates<float32>(cache, faceId);
+  // Unavoidable branch to verify integrity of subsequent function
+  // specifically because this an exposed function, however, the
+  // CPU should quickly be able to predict once it has run a few
+  // iterations of the function making it relatively lightweight
+  if(verts.size() != cache.NumVertsPerFace)
+  {
+    verts = std::vector<usize>(cache.NumVertsPerFace);
+  }
+  std::array<Point3Df, 3> points = GeometryMath::detail::GetFaceCoordinates<float32>(cache, faceId, verts);
 
   Point3Df ll = points[0];
   Point3Df ur = points[0];
@@ -118,9 +126,12 @@ BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfFaces(const nx::core::Tr
 
   detail::GeometryStoreCache cache(triangleGeom.getVertices()->getDataStoreRef(), triangleGeom.getFaces()->getDataStoreRef(), triangleGeom.getNumberOfVerticesPerFace());
 
+  // initialize temp storage 'verts' vector to avoid expensive
+  // calls during tight loops below
+  std::vector<usize> verts(cache.NumVertsPerFace);
   for(const auto& id : faceIds)
   {
-    auto bounds = FindBoundingBoxOfFace(cache, triangleGeom, id);
+    auto bounds = FindBoundingBoxOfFace(cache, triangleGeom, id, verts);
     Point3Df min = bounds.getMinPoint();
     Point3Df max = bounds.getMaxPoint();
 

src/simplnx/Utilities/Math/GeometryMath.hpp

@@ -43,27 +43,25 @@ template <typename T>
 concept FloatType = std::is_floating_point_v<T>;
 
 template <FloatType FloatT>
-std::array<Point3D<FloatT>, 3> GetFaceCoordinates(const GeometryStoreCache& cache, usize faceId)
+std::array<Point3D<FloatT>, 3> GetFaceCoordinates(const GeometryStoreCache& cache, usize faceId, std::vector<usize>& verts)
 {
   std::array<Point3D<FloatT>, 3> points;
-  std::vector<usize> verts(cache.NumVertsPerFace);
   {
     const usize offset = faceId * cache.NumVertsPerFace;
     if(offset + cache.NumVertsPerFace <= cache.FacesStoreRef.getSize())
     {
       for(usize i = 0; i < cache.NumVertsPerFace; i++)
       {
-        verts[i] = cache.FacesStoreRef.at(offset + i);
+        verts[i] = cache.FacesStoreRef[offset + i];
       }
     }
   }
-  for(usize index = 0; index < verts.size(); index++)
+  for(usize index = 0; index < cache.NumVertsPerFace; index++)
   {
     const usize offset = verts[index] * 3;
-    for(usize i = 0; i < 3; i++)
-    {
-      points[index][i] = static_cast<FloatT>(cache.VerticesStoreRef.at(offset + i));
-    }
+    points[index][0] = static_cast<FloatT>(cache.VerticesStoreRef.at(offset));
+    points[index][1] = static_cast<FloatT>(cache.VerticesStoreRef.at(offset + 1));
+    points[index][2] = static_cast<FloatT>(cache.VerticesStoreRef.at(offset + 2));
   }
   return points;
 }
@@ -401,7 +399,7 @@ nx::core::BoundingBox3Df SIMPLNX_EXPORT FindBoundingBoxOfRotatedFace(nx::core::T
  * @param faceId
  * @return nx::core::BoundingBox<float32>
  */
-nx::core::BoundingBox3Df FindBoundingBoxOfFace(const detail::GeometryStoreCache& cache, const nx::core::TriangleGeom& triangleGeom, int32 faceId);
+nx::core::BoundingBox3Df FindBoundingBoxOfFace(const detail::GeometryStoreCache& cache, const nx::core::TriangleGeom& triangleGeom, int32 faceId, std::vector<usize>& verts);
 
 /**
  * @param TriangleGeom* faces
@@ -588,6 +586,10 @@ char IsPointInPolyhedron(const nx::core::TriangleGeom& triangleGeomRef, const st
 
   detail::GeometryStoreCache cache(triangleGeomRef.getVertices()->getDataStoreRef(), triangleGeomRef.getFaces()->getDataStoreRef(), triangleGeomRef.getNumberOfVerticesPerFace());
 
+  // initialize temp storage 'verts' vector to avoid expensive
+  // calls during tight loops below
+  std::vector<usize> verts(cache.NumVertsPerFace);
+
   usize numFaces = faceIds.size();
   while(iter++ < numFaces)
   {
@@ -617,7 +619,7 @@ char IsPointInPolyhedron(const nx::core::TriangleGeom& triangleGeomRef, const st
       }
       else
       {
-        std::array<Point3D<T>, 3> coords = detail::GetFaceCoordinates<T>(cache, faceIds[face]);
+        std::array<Point3D<T>, 3> coords = detail::GetFaceCoordinates<T>(cache, faceIds[face], verts);
         code = RayIntersectsTriangle(ray, coords[0], coords[1], coords[2]);
       }
 

src/simplnx/Utilities/SampleSurfaceMesh.cpp

@@ -242,6 +242,11 @@ Result<> SampleSurfaceMesh::execute(SampleSurfaceMeshInputValues& inputValues)
   {
     // !!! DO NOT USE GeometryStoreCache ELSEWHERE, SPECIAL CASE !!!
     GeometryMath::detail::GeometryStoreCache cache(triangleGeom.getVertices()->getDataStoreRef(), triangleGeom.getFaces()->getDataStoreRef(), triangleGeom.getNumberOfVerticesPerFace());
+
+    // initialize temp storage 'verts' vector to avoid expensive
+    // calls during tight loops below
+    std::vector<usize> verts(cache.NumVertsPerFace);
+
     // traverse data again to get the faces belonging to each feature
     for(int32 i = 0; i < numFaces; i++)
     {
@@ -256,7 +261,7 @@ Result<> SampleSurfaceMesh::execute(SampleSurfaceMeshInputValues& inputValues)
         faceLists[g2][(linkLoc[g2])++] = i;
       }
       // find bounding box for each face
-      faceBBs.emplace_back(GeometryMath::FindBoundingBoxOfFace(cache, triangleGeom, i));
+      faceBBs.emplace_back(GeometryMath::FindBoundingBoxOfFace(cache, triangleGeom, i, verts));
     }
   }