Adsk Contrib - Allow PyOpenColorIO module to load DLLs from Windows P…

…ATH environment variable (AcademySoftwareFoundation#1759) * Allow PyOpenColorIO module to load DLLs from Windows PATH environment variable with an opt-out option in case the user want the default behavior of Python 3.8+. Signed-off-by: Cédrik Fuoco <[email protected]> * Fixing typos in comments Signed-off-by: Cédrik Fuoco <[email protected]> --------- Signed-off-by: Cédrik Fuoco <[email protected]> Co-authored-by: Doug Walker <[email protected]> Signed-off-by: Cédrik Fuoco <[email protected]>
autodesk-forks · Mar 24, 2023 · caa2fce · caa2fce
1 parent 0221599
commit caa2fce
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Showing 2 changed files with 33 additions and 3 deletions.
diff --git a/src/bindings/python/CMakeLists.txt b/src/bindings/python/CMakeLists.txt
@@ -227,16 +227,22 @@ target_compile_definitions(PyOpenColorIO
 		PY_VERSION_PATCH=${Python_VERSION_PATCH}
 )
 
+# Set to site-package location.
 if(WIN32)
     set(_Python_VARIANT_PATH "${CMAKE_INSTALL_LIBDIR}/site-packages")
 else()
     set(_Python_VARIANT_PATH "${CMAKE_INSTALL_LIBDIR}/python${Python_VERSION_MAJOR}.${Python_VERSION_MINOR}/site-packages")
 endif()
 
-# Create an internal global variable to access it in another scope but not publicly visible
-# using ccmake.
+# Create an internal global variable to access it in another scope but not publicly visible.
+# The site-package location is needed in setup_ocio.bat.in and setup_ocio.sh.in.
 set(PYTHON_VARIANT_PATH ${_Python_VARIANT_PATH} CACHE INTERNAL "")
 
+# Set to PyOpenColorIO site-package location.
+set(_PyOpenColorIO_SITE_PACKAGE_DIR "${PYTHON_VARIANT_PATH}/PyOpenColorIO")
+
 install(TARGETS PyOpenColorIO
-    LIBRARY DESTINATION ${_Python_VARIANT_PATH}
+    LIBRARY DESTINATION ${_PyOpenColorIO_SITE_PACKAGE_DIR}
 )
+
+install(FILES __init__.py DESTINATION ${_PyOpenColorIO_SITE_PACKAGE_DIR})
diff --git a/src/bindings/python/__init__.py b/src/bindings/python/__init__.py
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright Contributors to the OpenColorIO Project.
+
+import os, sys, platform
+
+#
+# Python 3.8+ has stopped loading DLLs from PATH environment variable on Windows.
+#
+# This code reproduce the old behavior (loading DLLs from PATH) by doing the following:
+# 1 - Tokenizing PATH
+# 2 - Checking that the directories exist and are not "."
+# 3 - Add them to the DLL load path.
+#
+# The behavior described above is opt-out which means that it is activated by default. 
+# A user can opt-out and use the default behavior of Python 3.8+ by setting OCIO_PYTHON_LOAD_DLLS_FROM_PATH 
+# environment variable to 0.
+#
+
+if sys.version_info >= (3, 8) and platform.system() == "Windows" and os.getenv("OCIO_PYTHON_LOAD_DLLS_FROM_PATH", "1") == "1":
+    for path in os.getenv("PATH", "").split(os.pathsep):
+        if os.path.exists(path) and path != ".":
+            os.add_dll_directory(path)
+
+from .PyOpenColorIO import *