From a98fb17a0be2bac26b4ddcc31f9b091e038bb5d1 Mon Sep 17 00:00:00 2001
From: Alexander Smorkalov <alexander.smorkalov@xperience.ai>
Date: Thu, 18 Apr 2024 11:49:42 +0300
Subject: [PATCH] Integrate ARM KleidiCV as OpenCV HAL.

---
 CMakeLists.txt                                    | 15 +++++++++++++++
 .../config_reference/config_reference.markdown    |  1 +
 2 files changed, 16 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 61f4ee2c154b..423c2a3cb3e0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,6 +13,8 @@ FATAL: In-source builds are not allowed.
 ")
 endif()
 
+# Useful for HALs if built as a CMake submodule
+set(OPENCV_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 
 include(cmake/OpenCVMinDepVersions.cmake)
 
@@ -258,6 +260,8 @@ OCV_OPTION(WITH_CAP_IOS "Enable iOS video capture" ON
   VERIFY HAVE_CAP_IOS)
 OCV_OPTION(WITH_CAROTENE "Use NVidia carotene acceleration library for ARM platform" (NOT CV_DISABLE_OPTIMIZATION)
   VISIBLE_IF (ARM OR AARCH64) AND NOT IOS AND NOT XROS)
+OCV_OPTION(WITH_KLEIDICV "Use KleidiCV library for ARM platforms" OFF
+  VISIBLE_IF (AARCH64))
 OCV_OPTION(WITH_CPUFEATURES "Use cpufeatures Android library" ON
   VISIBLE_IF ANDROID
   VERIFY HAVE_CPUFEATURES)
@@ -963,6 +967,13 @@ if(HAVE_OPENVX)
   endif()
 endif()
 
+if(WITH_KLEIDICV)
+  ocv_debug_message(STATUS "Enable KleidiCV acceleration")
+  if(NOT ";${OpenCV_HAL};" MATCHES ";kleidicv;")
+    set(OpenCV_HAL "kleidicv;${OpenCV_HAL}")
+  endif()
+endif()
+
 if(WITH_CAROTENE)
   ocv_debug_message(STATUS "Enable carotene acceleration")
   if(NOT ";${OpenCV_HAL};" MATCHES ";carotene;")
@@ -987,6 +998,10 @@ foreach(hal ${OpenCV_HAL})
     else()
       message(STATUS "Carotene: NEON is not available, disabling carotene...")
     endif()
+  elseif(hal STREQUAL "kleidicv")
+    add_subdirectory(3rdparty/kleidicv)
+    ocv_hal_register(KLEIDICV_HAL_LIBRARIES KLEIDICV_HAL_HEADERS KLEIDICV_HAL_INCLUDE_DIRS)
+    list(APPEND OpenCV_USED_HAL "KleidiCV (ver ${KLEIDICV_HAL_VERSION})")
   elseif(hal STREQUAL "openvx")
     add_subdirectory(3rdparty/openvx)
     ocv_hal_register(OPENVX_HAL_LIBRARIES OPENVX_HAL_HEADERS OPENVX_HAL_INCLUDE_DIRS)
diff --git a/doc/tutorials/introduction/config_reference/config_reference.markdown b/doc/tutorials/introduction/config_reference/config_reference.markdown
index dba280485fd3..7ced9a2536b1 100644
--- a/doc/tutorials/introduction/config_reference/config_reference.markdown
+++ b/doc/tutorials/introduction/config_reference/config_reference.markdown
@@ -623,6 +623,7 @@ Following build options are utilized in `opencv_contrib` modules, as stated [pre
 `CMAKE_TOOLCHAIN_FILE`
 
 `WITH_CAROTENE`
+`WITH_KLEIDICV`
 `WITH_CPUFEATURES`
 `WITH_EIGEN`
 `WITH_OPENVX`