Change pyAssimps library detection routine to work on Linux as well

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@564 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

port/PyAssimp/pyassimp/helper.py

@@ -8,60 +8,111 @@ import os
 import ctypes
 import structs
 import operator
+
 from errors import AssimpError
 from ctypes import POINTER
 
+additional_dirs, ext_whitelist = [],[]
 
+# populate search directories and lists of allowed file extensions
+# depending on the platform we're running on.
+if os.name=='posix':
+    additional_dirs.append('/usr/local/lib/')
+
+    # note - this won't catch libassimp.so.N.n, but 
+    # currently there's always a symlink called
+    # libassimp.so in /usr/local/lib.
+    ext_whitelist.append('.so')
+
+elif os.name=='nt':
+    ext_whitelist.append('.dll')
+
+print(additional_dirs)
 def vec2tuple(x):
-    """
-    Converts a VECTOR3D to a Tuple
-    """
+    """ Converts a VECTOR3D to a Tuple """
     return (x.x, x.y, x.z)
 
 
+def try_load_functions(library,dll,candidates):
+    """try to  functbind to aiImportFile and aiReleaseImport
+    
+    library - path to current lib
+    dll - ctypes handle to it
+    candidates - receives matching candidates
+
+    They serve as signal functions to detect assimp,
+    also they're currently the only functions we need.
+    insert (library,aiImportFile,aiReleaseImport,dll) 
+    into 'candidates' if successful.
+
+    """
+    try:
+        load = dll.aiImportFile
+        release = dll.aiReleaseImport
+    except AttributeError:
+        #OK, this is a library, but it has not the functions we need
+        pass
+    else:
+        #Library found!
+        load.restype = POINTER(structs.Scene)
+        
+        candidates.append((library, load, release, dll))
+
+
 def search_library():
-    """
-    Loads the assimp-Library.
-    
-    result (load-function, release-function)
+    """Loads the assimp-Library.
     
+    result (load-function, release-function)    
     exception AssimpError if no library is found
-    """
+    
+        """
     #this path
     folder = os.path.dirname(__file__)
-    
-    ctypes.windll.kernel32.SetErrorMode(0x8007)
-    
+
+    # silence 'DLL not found' message boxes on win
+    try:
+        ctypes.windll.kernel32.SetErrorMode(0x8007)
+    except AttributeError:
+        pass    
+
     candidates = []
     
-    #test every file
-    for filename in os.listdir(folder):
-        library = os.path.join(folder, filename)
-        
-        try:
-            dll = ctypes.cdll.LoadLibrary(library)
-        except:
-            #OK, this except is evil. But different OSs will throw different
-            #errors. So just ignore errors.
-            pass
-        else:
-            #get the functions
+    # test every file
+    for curfolder in [folder]+additional_dirs:
+        for filename in os.listdir(curfolder):
+            # our minimum requirement for candidates is that
+            # they should contain 'assimp' somewhere in 
+            # their name
+            if filename.lower().find('assimp')==-1 or\
+                os.path.splitext(filename)[-1].lower() not in ext_whitelist:
+                continue
+
+            library = os.path.join(curfolder, filename)
+            print 'Try ',library
             try:
-                load = dll.aiImportFile
-                release = dll.aiReleaseImport
-            except AttributeError:
-                #OK, this is a library, but it has not the functions we need
-                pass
-            else:
-                #Library found!
-                load.restype = POINTER(structs.Scene)
-                
-                candidates.append((library, load, release, dll))
+                dll = ctypes.cdll.LoadLibrary(library)
+            except:
+                # OK, this except is evil. But different OSs will throw different
+                # errors. So just ignore any errors.
+                continue
+
+            try_load_functions(library,dll,candidates)
     
     if not candidates:
-        #no library found
+        # no library found
         raise AssimpError, "assimp library not found"
     else:
-        #get the newest library
+        # get the newest library
         candidates = map(lambda x: (os.lstat(x[0])[-2], x), candidates)
-        return max(candidates, key=operator.itemgetter(0))[1][1:]
+        res = max(candidates, key=operator.itemgetter(0))[1]
+        print 'Taking ',res[0]
+
+        # XXX: if there are 1000 dll/so files containing 'assimp'
+        # in their name, do we have all of them in our address
+        # space now until gc kicks in?
+
+        # XXX: take version postfix of the .so on linux?
+        return res[1:]
+
+
+