Performance improvements, better readme and complete python bindings

examples/CMakeLists.txt

@@ -21,14 +21,18 @@ if(KPN_WEB_DEBUG)
     target_link_libraries(14_debug_hub PRIVATE kpn)
     kpn_target_enable_web_debug(14_debug_hub)
 endif()
-# 07 and 08 require the Python bindings — only add if built
-if(KPN_BUILD_PYTHON)
-    # These are Python scripts, not compiled targets — installed alongside kpn_python
-endif()
+# 07 and 08 are Python scripts — no compiled target needed.
 
 # 09 requires OpenCV — only build if found
 find_package(OpenCV QUIET COMPONENTS core imgproc highgui videoio)
 if(OpenCV_FOUND)
+    # Hybrid Python example: kpn_opencv module (requires both OpenCV and nanobind)
+    if(KPN_BUILD_PYTHON)
+        nanobind_add_module(kpn_opencv 09_opencv_cellshade/kpn_opencv.cpp)
+        target_link_libraries(kpn_opencv PRIVATE kpn ${OpenCV_LIBS})
+        target_compile_definitions(kpn_opencv PRIVATE KPN_BUILD_PYTHON)
+        message(STATUS "KPN++ kpn_opencv Python module: building (OpenCV ${OpenCV_VERSION})")
+    endif()
     add_executable(09_opencv_cellshade 09_opencv_cellshade/main.cpp)
     target_link_libraries(09_opencv_cellshade PRIVATE kpn ${OpenCV_LIBS})