Commit c528f6fa4100c13a662e2d2a6d6951e24daf14cf
2002-12-18T22:43:07
* src/base/ftobjs.c (find_unicode_charmap): added some comments to better explain what's happening there * src/base/ftobjs.c (open_face): included Graham Asher's fix to prevent faces without Unicode charmaps from loading
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diff --git a/ChangeLog b/ChangeLog
index fcc3589..633fa6a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2002-12-17 David Turner <david@freetype.org>
+
+ * src/base/ftobjs.c (find_unicode_charmap): added some comments to
+ better explain what's happening there
+
+ * src/base/ftobjs.c (open_face): included Graham Asher's fix to
+ prevent faces without Unicode charmaps from loading
+
2002-12-16 David Turner <david@freetype.org>
* docs/VERSION.DLL: updating document to better explain the differences between
diff --git a/src/base/ftobjs.c b/src/base/ftobjs.c
index 3333c92..dcf9816 100644
--- a/src/base/ftobjs.c
+++ b/src/base/ftobjs.c
@@ -731,6 +731,29 @@
if ( !first )
return FT_Err_Invalid_CharMap_Handle;
+ /*
+ * the original TrueType specification(s) only specified charmap
+ * formats that are capable of mapping 8 or 16 bit character codes to
+ * glyph indices.
+ *
+ * however, recent updates to the Apple and OpenType specifications
+ * introduced new formats that are capable of mapping 32-bit character
+ * codes as well. And these are already used on some fonts, mainly to
+ * map non-BMP asian ideographs as defined in Unicode.
+ *
+ * for compatibility purposes, these fonts generally come with
+ * *several* Unicode charmaps:
+ *
+ * - one of them in the "old" 16-bit format, that cannot access
+ * all glyphs in the font
+ *
+ * - another one in the "new" 32-bit format, that can access all
+ * the glyphs.
+ *
+ * this function has been written to always favor a 32-bit charmap
+ * when found. Otherwise, a 16-bit one is returned when found
+ */
+
/* since the `interesting' table, with id's 3,10, is normally the */
/* last one, we loop backwards. This looses with type1 fonts with */
/* non-BMP characters (<.0001%), this wins with .ttf with non-BMP */
@@ -746,10 +769,11 @@
/* XXX If some new encodings to represent UCS-4 are added, */
/* they should be added here. */
- if ( ( cur[0]->platform_id == TT_PLATFORM_MICROSOFT
- && cur[0]->encoding_id == TT_MS_ID_UCS_4 )
- || ( cur[0]->platform_id == TT_PLATFORM_APPLE_UNICODE
- && cur[0]->encoding_id == TT_APPLE_ID_UNICODE_32 ) )
+ if ( ( cur[0]->platform_id == TT_PLATFORM_MICROSOFT &&
+ cur[0]->encoding_id == TT_MS_ID_UCS_4 ) ||
+ ( cur[0]->platform_id == TT_PLATFORM_APPLE_UNICODE &&
+ cur[0]->encoding_id == TT_APPLE_ID_UNICODE_32 ) )
+
/* Hurray! We found a UCS-4 charmap. We can stop the scan! */
{
face->charmap = cur[0];
@@ -833,10 +857,13 @@
/* select Unicode charmap by default */
error2 = find_unicode_charmap( face );
- /* if no Unicode charmap can be found, return FT_Err_Invalid_Argument */
+
+ /* if no Unicode charmap can be found, FT_Err_Invalid_CharMap_Handle is
+ * returned.
+ */
/* no error should happen, but we want to play safe. */
- if ( error2 && error2 != FT_Err_Invalid_Argument )
+ if ( error2 && error2 != FT_Err_Invalid_CharMap_Handle )
{
error = error2;
goto Fail;