[Win32] Add checks before trying to import Sofa modules (#169)

* add checks before trying to import Sofa modules

* Update __init__.py

indent error...

* Improve __init__.py

* Improve __init__.py (2)

Co-authored-by: Guillaume Paran <[email protected]>

Author: fredroy

bindings/Sofa/package/__init__.py

@@ -34,6 +34,72 @@
 import traceback
 import importlib
 
+print("---------------------------------------")
+print("Checking SOFA_ROOT and SOFAPYTHON3_ROOT")
+
+# check if SOFA_ROOT has been (well) set
+sofa_root = os.environ.get('SOFA_ROOT')
+if sofa_root:
+    print("Using environment variable SOFA_ROOT: " + sofa_root)
+else:
+    print("Warning: environment variable SOFA_ROOT is empty. Trying to guess it.")
+    # try a guess from <sofa_root>/plugins/SofaPython3/lib/python3/site-packages/Sofa
+    sofa_root_guess = os.path.abspath(os.path.dirname(os.path.realpath(__file__)) + '/../../../../../..') 
+    if os.path.isdir(os.path.abspath(sofa_root_guess + '/lib' )):
+        print("Guessed SOFA_ROOT: " + sofa_root_guess)
+        sofa_root = sofa_root_guess
+    else:
+        print("Warning: cannot guess SOFA_ROOT", 
+        "Loading SOFA libraries will likely fail and/or SOFA won't find its resources.")
+
+# check if SOFAPYTHON3_ROOT has been (well) set
+sofapython3_root = os.environ.get('SOFAPYTHON3_ROOT')
+if sofapython3_root:
+    print("Using environment variable SOFAPYTHON3_ROOT: " + sofapython3_root)
+else:
+    print("Warning: environment variable SOFAPYTHON3_ROOT is empty. Trying to guess it.")
+    # try a guess from <sofapython3_root>/lib/python3/site-packages/Sofa
+    sofapython3_root_guess = os.path.abspath(os.path.dirname(os.path.realpath(__file__)) + '/../../../..') 
+    if os.path.isdir(os.path.abspath(sofapython3_root_guess + '/lib' )):
+        print("Guessed SOFAPYTHON3_ROOT: " + sofapython3_root_guess)
+        sofapython3_root = sofapython3_root_guess
+    else:
+        print("Warning: cannot guess SOFAPYTHON3_ROOT", 
+        "Loading SofaPython3 modules will likely fail.")
+
+if sofa_root and sys.platform == 'win32':
+    # Windows-only: starting from python 3.8, python wont read the env. variable PATH to get SOFA's dlls. 
+    # os.add_dll_directory() is the new way to add paths for python to get external libraries.
+    sofa_bin_path = sofa_root + "\\bin"
+    sofa_file_test = sofa_bin_path + "\\Sofa.Helper.dll"
+    sofapython3_bin_path = sofapython3_root + "\\bin"
+    sofapython3_file_test = sofapython3_bin_path + "\\SofaPython3.dll"
+    
+    if not os.path.isfile(sofa_file_test):
+        print("Warning: environment variable SOFA_ROOT is set but seems invalid.",
+        "Loading SOFA libraries will likely fail.")
+        print("SOFA_ROOT is currently: " + sofa_root)
+    if not os.path.isfile(sofapython3_file_test):
+        print("Warning: cannot find SofaPython3.dll at path: " + sofapython3_bin_path)
+        print("This path will NOT be added to the DLL search path.", 
+        "Loading SofaPython3 python modules will likely fail.")
+    
+    if sys.version_info.minor >= 8:
+        # Starting from python3.8 we need to explicitly find SOFA libraries
+        if os.path.isfile(sofa_file_test):
+            os.add_dll_directory(sofa_bin_path)
+        if os.path.isfile(sofapython3_file_test):
+            os.add_dll_directory(sofapython3_bin_path)
+    else:
+        # Add temporarily the bin/lib path to the env variable PATH
+        if os.path.isfile(sofa_file_test):
+            os.environ['PATH'] = sofa_bin_path + os.pathsep + os.environ['PATH']
+        if os.path.isfile(sofapython3_file_test):
+            os.environ['PATH'] = sofapython3_bin_path + os.pathsep + os.environ['PATH']
+
+print("---------------------------------------")
+sys.stdout.flush()
+
 import Sofa.constants
 import Sofa.Helper
 import Sofa.Core