Add USE_SHARED_OPENCV and USE_SHARED_ONNXRUNTIME options (#185)

* Support shared libs on Linux for FlatPak

* Format

* Fix wording

* Update CMakeLists.txt

* Update CMakeLists.txt

* Change the word shared into system

CMakeLists.txt

@@ -1,6 +1,7 @@
 cmake_minimum_required(VERSION 3.25.2)
 
 set(CMAKE_CXX_STANDARD 20)
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
 
 # Change obs-plugintemplate to your plugin's name in a machine-readable format (e.g.:
 # obs-myawesomeplugin) and set
@@ -45,8 +46,43 @@ configure_file(src/plugin-macros.h.in ${CMAKE_SOURCE_DIR}/src/plugin-macros.gene
 
 target_sources(${CMAKE_PROJECT_NAME} PRIVATE src/plugin-macros.generated.h)
 
-include(cmake/BuildMyOnnxruntime.cmake)
-include(cmake/BuildMyOpenCV.cmake)
+set(USE_SYSTEM_ONNXRUNTIME
+    OFF
+    CACHE STRING "Use system ONNX Runtime")
+if(USE_SYSTEM_ONNXRUNTIME)
+  if(OS_LINUX)
+    find_package(Onnxruntime 1.14.1 REQUIRED)
+    add_library(Onnxruntime SHARED IMPORTED)
+    set_target_properties(Onnxruntime PROPERTIES IMPORTED_LOCATION ${Onnxruntime_LIBRARIES})
+    set(Onnxruntime_INCLUDE_PATH
+        ${Onnxruntime_INCLUDE_DIR} ${Onnxruntime_INCLUDE_DIR}/onnxruntime
+        ${Onnxruntime_INCLUDE_DIR}/onnxruntime/core/session
+        ${Onnxruntime_INCLUDE_DIR}/onnxruntime/core/providers/cpu)
+    set_target_properties(Onnxruntime PROPERTIES INTERFACE_INCLUDE_DIRECTORIES
+                                                 "${Onnxruntime_INCLUDE_PATH}")
+  else()
+    message(FATAL_ERROR "System ONNX Runtime is only supported on Linux!")
+  endif()
+else()
+  include(cmake/BuildMyOnnxruntime.cmake)
+endif()
+
+set(USE_SYSTEM_OPENCV
+    OFF
+    CACHE STRING "Use system OpenCV")
+if(USE_SYSTEM_OPENCV)
+  if(OS_LINUX)
+    find_package(OpenCV REQUIRED COMPONENTS core imgproc)
+    add_library(OpenCV SHARED IMPORTED)
+    set_target_properties(OpenCV PROPERTIES IMPORTED_LOCATION ${OpenCV_LIBRARIES})
+    set_target_properties(OpenCV PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${OpenCV_INCLUDE_DIRS}")
+  else()
+    message(FATAL_ERROR "System OpenCV is only supported on Linux!")
+  endif()
+else()
+  include(cmake/BuildMyOpenCV.cmake)
+endif()
+
 if(OS_WINDOWS)
   install(IMPORTED_RUNTIME_ARTIFACTS Onnxruntime::DirectML DESTINATION "${OBS_PLUGIN_DESTINATION}")
 endif()