Extend CID service functions to handle CID-keyed CFFs as CID fonts.

* include/freetype/ftcid.h (FT_Get_CID_Is_Internally_CID_keyed,
FT_Get_CID_From_Glyph_Index): New functions.

* include/freetype/internal/services/svcid.h
(FT_CID_GetIsInternallyCIDKeyedFunc,
FT_CID_GetCIDFromGlyphIndexFunc): New function typedefs.
(CID Service): Use them.

* src/base/ftcid.c: Include FT_CID_H.
(FT_Get_CID_Is_Internally_CID_keyed, FT_Get_CID_From_Glyph_Index):
New functions.

* src/cff/cffdrivr.c (cff_get_is_cid, cff_get_cid_from_glyph_index):
New functions.
(cff_service_cid_info): Add them.
* src/cff/cffload.c (cff_font_load): Don't free `font->charset.sids'
-- it is needed for access as a CID-keyed font.  It gets deleted
later on.

* src/cid/cidriver.c (cid_get_is_cid, cid_get_cid_from_glyph_index):
New functions.
(cid_service_cid_info): Add them.

* docs/CHANGES: Updated.

1 files changed, 34 insertions, 1 deletions

diff --git a/src/cid/cidriver.c b/src/cid/cidriver.c
index f650ee1d9..b41d5d6f0 100644
--- a/src/cid/cidriver.c
+++ b/src/cid/cidriver.c
@@ -122,9 +122,42 @@
   }
 
 
+  static FT_Error
+  cid_get_is_cid( CID_Face  face,
+                  FT_Bool  *is_cid )
+  {
+    FT_Error  error = CID_Err_Ok;
+    FT_UNUSED( face );
+
+
+    if ( is_cid )
+      *is_cid = 1; /* cid driver is only used for CID keyed fonts */
+
+    return error;
+  }
+
+
+  static FT_Error
+  cid_get_cid_from_glyph_index( CID_Face  face,
+                                FT_UInt   glyph_index,
+                                FT_UInt  *cid )
+  {
+    FT_Error  error = CID_Err_Ok;
+    FT_UNUSED( face );
+
+
+    if ( cid )
+      *cid = glyph_index; /* identity mapping */
+
+    return error;
+  }
+
+
   static const FT_Service_CIDRec  cid_service_cid_info =
   {
-    (FT_CID_GetRegistryOrderingSupplementFunc)cid_get_ros
+     (FT_CID_GetRegistryOrderingSupplementFunc)cid_get_ros,
+     (FT_CID_GetIsInternallyCIDKeyedFunc)      cid_get_is_cid,
+     (FT_CID_GetCIDFromGlyphIndexFunc)         cid_get_cid_from_glyph_index
   };