Support for multiple mtllib files.

2 files changed, 3 insertions, 2 deletions

diff --git a/src/Wavefront.hs b/src/Wavefront.hs
index 32959d4..cae6508 100644
--- a/src/Wavefront.hs
+++ b/src/Wavefront.hs
@@ -114,7 +114,8 @@ buildOBJ = nullBuilder
         modify' $ second $ \e -> e { elObject = Just o }
     , usemtl = \x -> do
         let mtl = decodeUtf8 x
-        modify' $ second $ \e -> e { elMtl = Just mtl }
+        libs <- DList.toList <$> gets (objMtlLibs . fst)
+        modify' $ second $ \e -> e { elMtl = Just (length libs,mtl) }
     , smoothingGroup = \x -> when (x > 0) $ do
         modify $ second $ \e -> e { elSmoothingGroup = fromIntegral x }
     }
diff --git a/src/Wavefront/Types.hs b/src/Wavefront/Types.hs
index 2e49ba9..99bbb15 100644
--- a/src/Wavefront/Types.hs
+++ b/src/Wavefront/Types.hs
@@ -161,7 +161,7 @@ pattern Quad a b c d = Face a b c [d]
 data Element a = Element {
     elObject         :: Maybe Text
   , elGroups         :: [Text]
-  , elMtl            :: Maybe Text
+  , elMtl            :: Maybe (Int,Text) -- Size of stack of mtllibs, mtlname
   , elSmoothingGroup :: Natural
   , elValue          :: a
   } deriving (Eq,Ord,Show,Functor)