From 6784ad458a39a3a52e82f0de1af177281219b3ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?D=C5=BEenan=20Zuki=C4=87?= <dzenan.zukic@kitware.com>
Date: Thu, 4 Jun 2026 16:21:52 -0400
Subject: [PATCH] ENH: Wrap BSplineTransform for 2D-2D and 4D-4D case

Currently available combinations are as follows:

<itkTemplate itk::BSplineTransform>
Options:
  [<itkCType double>, 2, 3]
  [<itkCType double>, 3, 3]
  [<itkCType double>, 4, 3]
---
 .../wrapping/itkBSplineBaseTransform.wrap       |  3 +++
 .../Transform/wrapping/itkBSplineTransform.wrap |  3 +++
 .../Core/Transform/wrapping/test/CMakeLists.txt | 13 +++++++++++++
 Wrapping/WrapITKTypes.cmake                     | 17 +++++++++++++----
 4 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/Modules/Core/Transform/wrapping/itkBSplineBaseTransform.wrap b/Modules/Core/Transform/wrapping/itkBSplineBaseTransform.wrap
index 512527a66cc..616f363d34a 100644
--- a/Modules/Core/Transform/wrapping/itkBSplineBaseTransform.wrap
+++ b/Modules/Core/Transform/wrapping/itkBSplineBaseTransform.wrap
@@ -1,5 +1,8 @@
 itk_wrap_class("itk::BSplineBaseTransform" POINTER)
 foreach(d ${ITK_WRAP_IMAGE_DIMS})
   itk_wrap_template("${ITKM_D}${d}3" "${ITKT_D},${d},3")
+  if (NOT ${d} EQUAL 3)
+    itk_wrap_template("${ITKM_D}${d}${d}" "${ITKT_D},${d},${d}")
+  endif()
 endforeach()
 itk_end_wrap_class()
diff --git a/Modules/Core/Transform/wrapping/itkBSplineTransform.wrap b/Modules/Core/Transform/wrapping/itkBSplineTransform.wrap
index a170e3efffd..91ed45a9d6b 100644
--- a/Modules/Core/Transform/wrapping/itkBSplineTransform.wrap
+++ b/Modules/Core/Transform/wrapping/itkBSplineTransform.wrap
@@ -1,5 +1,8 @@
 itk_wrap_class("itk::BSplineTransform" POINTER)
 foreach(d ${ITK_WRAP_IMAGE_DIMS})
   itk_wrap_template("${ITKM_D}${d}3" "${ITKT_D},${d},3")
+  if (NOT ${d} EQUAL 3)
+    itk_wrap_template("${ITKM_D}${d}${d}" "${ITKT_D},${d},${d}")
+  endif()
 endforeach()
 itk_end_wrap_class()
diff --git a/Modules/Core/Transform/wrapping/test/CMakeLists.txt b/Modules/Core/Transform/wrapping/test/CMakeLists.txt
index 51fbaec3979..7e2a6f6d86b 100644
--- a/Modules/Core/Transform/wrapping/test/CMakeLists.txt
+++ b/Modules/Core/Transform/wrapping/test/CMakeLists.txt
@@ -6,4 +6,17 @@ if(ITK_WRAP_PYTHON)
     ${CMAKE_CURRENT_SOURCE_DIR}/itkTransformSerializationTest.py
     DATA{Baseline/BSplineDeformationTransformDisplacements5.txt}
     ${ITK_EXAMPLE_DATA_ROOT}/DiagonalLines.png)
+
+  itk_python_expression_add_test(
+    NAME PythonInstantiateBSplineTransform2D2D
+    EXPRESSION "t = itk.BSplineTransform[itk.D, 2, 2].New()"
+  )
+
+  list(FIND ITK_WRAP_IMAGE_DIMS 4 wrap_4_index)
+  if(wrap_4_index GREATER -1)
+    itk_python_expression_add_test(
+      NAME PythonInstantiateBSplineTransform4D4D
+      EXPRESSION "t = itk.BSplineTransform[itk.D, 4, 4].New()"
+    )
+  endif()
 endif()
diff --git a/Wrapping/WrapITKTypes.cmake b/Wrapping/WrapITKTypes.cmake
index ac2347a9e65..738052883b4 100644
--- a/Wrapping/WrapITKTypes.cmake
+++ b/Wrapping/WrapITKTypes.cmake
@@ -135,8 +135,10 @@ wrap_type("itk::FixedArray" "FA" "itkFixedArray.h")
 set(dims ${ITK_WRAP_IMAGE_DIMS_INCREMENTED})
 foreach(d ${ITK_WRAP_IMAGE_DIMS})
   math(EXPR d2 "${d} * 2")
+
   # for itk::SymmetricSecondRankTensor
   math(EXPR d3 "${d} * (${d} + 1) / 2")
+
   list(
     APPEND
     dims
@@ -149,9 +151,9 @@ endforeach()
 # needs to have defined sizes for:
 # - ITK_WRAP_IMAGE_DIMS_INCREMENTED
 # - ITK_WRAP_VECTOR_COMPONENTS_INCREMENTED
-# Dimensions 1;2;3;4;6 should always be wrapped.
+# Dimensions 1;2;3;4;6;9 should always be wrapped.
 
-unique(array_sizes "${dims};1;2;3;4;6;${ITK_WRAP_VECTOR_COMPONENTS_INCREMENTED}")
+unique(array_sizes "${dims};1;2;3;4;6;9;${ITK_WRAP_VECTOR_COMPONENTS_INCREMENTED}")
 
 # 3-D FixedArrays are required as superclass of rgb pixels
 # TODO: Do we need fixed arrays for all of these types? For just the selected
@@ -178,8 +180,15 @@ foreach(d ${ITK_WRAP_IMAGE_DIMS})
   foreach(i RANGE 1 ${d})
     math(EXPR comp "${comp}*4")
   endforeach()
-  add_template("${ITKM_D}${comp}" "${ITKT_D},${comp}")
-  add_template("${ITKM_UL}${comp}" "${ITKT_UL},${comp}")
+
+  # Check if computed comp dimension has already wrapped above
+  list(FIND array_sizes ${comp} array_sizes_index)
+
+  if(array_sizes_index LESS 0)
+    # Not already in array_sizes
+    add_template("${ITKM_D}${comp}" "${ITKT_D},${comp}")
+    add_template("${ITKM_UL}${comp}" "${ITKT_UL},${comp}")
+  endif()
 endforeach()
 end_wrap_type()
 set(itk_Wrap_FixedArray ${WRAPPER_TEMPLATES})