[sfnt] Implement support for `OS/2' table version 5.

See

  http://typedrawers.com/discussion/470/new-microsoft-size-specific-design-selection-mechanism

for the announcement.

* include/freetype/tttables.h (TT_OS2): Add fields
`usLowerPointSize' and `usUpperPointSize'.  Since FreeType returns
this structure only as a pointer through `FT_Get_Sfnt_Table', there
shouldn't be any ABI problems.

* src/sfnt/ttload.c (tt_face_load_os2): Implement it.

* docs/CHANGES: Updated.

ChangeLog

@@ -1,3 +1,22 @@
+2013-10-27  Werner Lemberg  <wl@gnu.org>
+
+	[sfnt] Implement support for `OS/2' table version 5.
+
+	See
+
+	  http://typedrawers.com/discussion/470/new-microsoft-size-specific-design-selection-mechanism
+
+	for the announcement.
+
+	* include/freetype/tttables.h (TT_OS2): Add fields
+	`usLowerPointSize' and `usUpperPointSize'.  Since FreeType returns
+	this structure only as a pointer through `FT_Get_Sfnt_Table', there
+	shouldn't be any ABI problems.
+
+	* src/sfnt/ttload.c (tt_face_load_os2): Implement it.
+
+	* docs/CHANGES: Updated.
+
 2013-10-24  Werner Lemberg  <wl@gnu.org>
 
 	* README.git, docs/CHANGES, docs/INSTALL: Updated.

docs/CHANGES

@@ -14,11 +14,14 @@ CHANGES BETWEEN 2.5 and 2.5.1
 
   II. IMPORTANT CHANGES
 
-    - WOFF support has been added.
+    - WOFF font format support has been added.
 
     - The auto-hinter now supports Hebrew.  Greek and Cyrillic support
       has been improved.
 
+    - Support for the forthcoming `OS/2'  SFNT table version 5, as can
+      be found e.g. in the `Sitka' font family for Windows 8.1.
+
 
   III. MISCELLANEOUS
 
@@ -28,8 +31,12 @@ CHANGES BETWEEN 2.5 and 2.5.1
     - `ftgrid' has been updated to toggle various engines with the `H'
       key, similar to `ftview' and `ftdiff'.
 
-    - `ttdebug' now displays twilight data; key `t' shows the twilight
-      point table.
+    - Some keys  in `ttdebug' have  been reassigned from  lowercase to
+      their uppercase equivalents; for example `q' to quit the program
+      is now `Q'.
+
+    - `ttdebug' now displays  twilight and storage area  data; key `T'
+      shows the twilight point table, key `S' the storage data.
 
     - Better support of ARMv7 and x86_64 processors.
 

include/freetype/tttables.h

@@ -340,8 +340,8 @@ FT_BEGIN_HEADER
   /*    TT_OS2                                                             */
   /*                                                                       */
   /* <Description>                                                         */
-  /*    A structure used to model a TrueType OS/2 table. This is the long  */
-  /*    table version.  All fields comply to the TrueType specification.   */
+  /*    A structure used to model a TrueType OS/2 table.  All fields       */
+  /*    comply to the OpenType specification.                              */
   /*                                                                       */
   /*    Note that we now support old Mac fonts that do not include an OS/2 */
   /*    table.  In this case, the `version' field is always set to 0xFFFF. */
@@ -396,6 +396,11 @@ FT_BEGIN_HEADER
     FT_UShort  usBreakChar;
     FT_UShort  usMaxContext;
 
+    /* only version 5 tables: */
+
+    FT_UShort  usLowerPointSize;
+    FT_UShort  usUpperPointSize;
+
   } TT_OS2;
 
 

src/sfnt/ttload.c

@@ -1003,7 +1003,8 @@
       FT_FRAME_END
     };
 
-    static const FT_Frame_Field  os2_fields_extra[] =
+    /* `OS/2' version 1 and newer */
+    static const FT_Frame_Field  os2_fields_extra1[] =
     {
       FT_FRAME_START( 8 ),
         FT_FRAME_ULONG( ulCodePageRange1 ),
@@ -1011,6 +1012,7 @@
       FT_FRAME_END
     };
 
+    /* `OS/2' version 2 and newer */
     static const FT_Frame_Field  os2_fields_extra2[] =
     {
       FT_FRAME_START( 10 ),
@@ -1022,6 +1024,15 @@
       FT_FRAME_END
     };
 
+    /* `OS/2' version 5 and newer */
+    static const FT_Frame_Field  os2_fields_extra5[] =
+    {
+      FT_FRAME_START( 4 ),
+        FT_FRAME_USHORT( usLowerPointSize ),
+        FT_FRAME_USHORT( usUpperPointSize ),
+      FT_FRAME_END
+    };
+
 
     /* We now support old Mac fonts where the OS/2 table doesn't  */
     /* exist.  Simply put, we set the `version' field to 0xFFFF   */
@@ -1042,11 +1053,13 @@
     os2->usDefaultChar    = 0;
     os2->usBreakChar      = 0;
     os2->usMaxContext     = 0;
+    os2->usLowerPointSize = 0;
+    os2->usUpperPointSize = 0;
 
     if ( os2->version >= 0x0001 )
     {
       /* only version 1 tables */
-      if ( FT_STREAM_READ_FIELDS( os2_fields_extra, os2 ) )
+      if ( FT_STREAM_READ_FIELDS( os2_fields_extra1, os2 ) )
         goto Exit;
 
       if ( os2->version >= 0x0002 )
@@ -1054,6 +1067,13 @@
         /* only version 2 tables */
         if ( FT_STREAM_READ_FIELDS( os2_fields_extra2, os2 ) )
           goto Exit;
+
+        if ( os2->version >= 0x0005 )
+        {
+          /* only version 5 tables */
+          if ( FT_STREAM_READ_FIELDS( os2_fields_extra5, os2 ) )
+            goto Exit;
+        }
       }
     }