better OSX support, I think

direct/src/extensions_native/extension_native_helpers.py

@@ -3,49 +3,70 @@ __all__ = ["Dtool_ObjectToDict", "Dtool_funcToMethod", "Dtool_PreloadDLL"]
 
 import imp,sys,os
 
-is_python_d = False
+# The following code exists to work around a problem that exists
-dll_suffix = ''
+# with Python 2.5 or greater.
-dll_ext = '.dll'
-if (sys.platform == "darwin"):
-    dll_ext = '.dylib'
 
-if (sys.platform == "win32"):
+# Specifically, Python 2.5 is designed to import files named *.pyd
-    # If we launched from python_d.exe, we need to load libpanda_d.dll, etc.
+# only; it will not import files named *.dll (or *.so).  We work
-    is_python_d = (sys.executable.endswith('_d.exe'))
+# around this problem by explicitly preloading all of the dll's we
-    if is_python_d:
+# expect to need.
+
+dll_suffix = ''
+if sys.platform == "win32":
+    # On Windows, dynamic libraries end in ".dll".
+    dll_ext = '.dll'
+
+    # If we launched from python_d.exe, we need to load
+    # libpanda_d.dll, etc.
+    if sys.executable.endswith('_d.exe'):
         dll_suffix = '_d'
 
+else:
+    # On OSX or Linux, dynamic libraries end in ".so".  OSX also
+    # provides *.dylib files, but these are apparently not intended to
+    # be imported directly.
+    dll_ext = '.so'
+
+if sys.platform == "win32":
+    # On Windows, we must furthermore ensure that the PATH is modified
+    # to locate all of the DLL files.
+
+    # First, search for the directory that contains all of our compiled
+    # modules.
     target = None
     filename = "libpandaexpress%s%s" % (dll_suffix, dll_ext)
     for dir in sys.path + [sys.prefix]:
         lib = os.path.join(dir, filename)
         if (os.path.exists(lib)):
             target = dir
-    if (target == None):
+    if target == None:
         message = "Cannot find %s" % (filename)
         raise message
-    path=os.environ["PATH"]
+
-    if (path.startswith(target+";")==0):
+    # And add that directory to the system path.
-        os.environ["PATH"] = target+";"+path
+    path = os.environ["PATH"]
+    if not path.startswith(target + ";"):
+        os.environ["PATH"] = target + ";" + path
 
 def Dtool_PreloadDLL(module):
-    """ Preloading solves the problem that python 2.5 on
-    windows can't find DLLs - it can only find PYDs.  The
-    preloader is able to find DLLs."""
-
-    if (sys.platform != "win32" and sys.platform != "darwin"):
-        return
     if (sys.modules.has_key(module)):
         return
+
+    # Search for the appropriate directory.
     target = None
+    filename = module + dll_suffix + dll_ext
     for dir in sys.path + [sys.prefix]:
-        lib = os.path.join(dir, module + dll_suffix + dll_ext)
+        lib = os.path.join(dir, filename)
         if (os.path.exists(lib)):
             target = dir
             break
-    if (target == None):
+    if target == None:
-        raise "DLL loader cannot find "+module+"."
+        message = "DLL loader cannot find %s." % (module)
-    imp.load_dynamic(module, os.path.join(target, module + dll_suffix + dll_ext))
+        raise message
+
+    # Now import the file explicitly.
+    pathname = os.path.join(target, filename)
+    imp.load_dynamic(module, pathname)
 
 Dtool_PreloadDLL("libpandaexpress")
 from libpandaexpress import *