[Freetype] load glyph error

[Brian Stell]

I have a prototype integration of FreeType2 in the Mozilla browser. 
It works well on my Redhat 6.2 and Redhat 7.1 systems.

I have a user that is running Debian (with FreeType from a Debian 
SID) who is seeing the FT_Load_Glyph call fail but seeing the cache
manager succeed in getting the glyph.

In the first phase the code directly opens all the fonts to 
generate a catalog. This works for me but FT_Load_Glyph fails for 
this user.

In the second phase the code accesses fonts using the cache 
manager and displays text. This works for both me and this
user.

Here is the code in the first phase:

  sFreeTypeInitError = FT_Init_FreeType(&sFreeTypeLibrary);
  if (sFreeTypeInitError) {
    do not use freetype
  ...
  FT_Error error = FTC_Manager_New(sFreeTypeLibrary, 0, 0, 0,
                      nsFreeTypeFaceRequester, 0, &sFTCacheManager);
  NS_ASSERTION(error==0, "failed to create FreeType Cache manager");
  error = FTC_Image_Cache_New(sFTCacheManager, &sImageCache);
  NS_ASSERTION(error==0, "failed to create FreeType image cache");
  ...

  // open the font
  fterror = FT_New_Face(aFreeTypeLibrary, aFontFileName, 0, &face);
  if ((fterror) || (!FT_IS_SCALABLE(face))) {
    ignore this font 
  ...
  tt_os2 = (TT_OS2 *)FT_Get_Sfnt_Table(face, ft_sfnt_os2);
  if (!tt_os2) {
    FONT_CATALOG_PRINTF(("unable to get OS2 table"));
    ignore this font 
  ...
  for (i=0; i<len; i++) { // len = 0x10000
    glyph_index = FT_Get_Char_Index(face, (FT_ULong)i);
    if (!glyph_index)
      continue;
    fterror = FT_Load_Glyph(face, glyph_index, FT_LOAD_DEFAULT);
    if (fterror) {
        printf("i = %d, glyph_index=%d, fterror = %d, face = %p\n", 
                        i, glyph_index, fterror, face);
      continue;
    }

The FT_Load_Glyph returns a non-zero error:

    i = 33, glyph_index = 4, fterror = 1090, face = 0x836af38
    i = 34, glyph_index = 5, fterror = 1090, face = 0x836af38
    i = 35, glyph_index = 6, fterror = 1090, face = 0x836af38
    i = 36, glyph_index = 7, fterror = 1090, face = 0x836af38
    ...

The error code is decimal 1090 which is 0x442.

If I understand the error codes this means module 4 and error 
code 0x42.

But module 4 is CID not TrueType and there does not appear to 
be an error code 0x42.

Any thoughts?

The other font values seem okay:

    FontFileName=/usr/local/lib/ttffonts/formal-436.ttf
    FamilyName=Formal436 BT
    FaceIndex=0
    StyleName=Regular
    NumGlyphs=260
    FaceFlags=0x00000259
    StyleFlags=0x00000000
    Weight=400
    Width=5
    CodePageRange1=0x00000000
    CodePageRange2=0x00000000
    VendorID=Bits


Here is information on the user's system:

    Debian sid
    Linux terminus 2.4.9 #1 SMP Fri Aug 17 11:38:08 EDT 2001 
      i686 unknown
    ii  libc6 2.2.4-1 GNU C Library: Shared libraries and
      Timezone dat
    ii  xlibs 4.1.0-2 X Window System client libraries

    ii  libfreetype6  2.0.2.20010514-1 FreeType 2 font engine, 
      shared library files.
    ii  libfreetype6-dev 2.0.2.20010514-1 FreeType 2 font engine, 
      development files


Here is later bit of code that does the drawing:

  // get the glyph and draw it to a XImage
  for (PRUint32 i=0; i<aLength; i++) {
    glyph_index = FT_Get_Char_Index(face, (FT_ULong)aString[i]);
    error = FTC_Image_Cache_Lookup(nsFreeType::sImageCache,
                                   &mImageDesc, glyph_index, &glyph);
    if (error) {
      // draw an empty box for the missing character
      ...
      continue;
    }
    ...
    // draw the glyph to a (local) XImage
    FT_BitmapGlyph slot = (FT_BitmapGlyph)glyph;
    (*nsFreeType::sBlitGlyph)(ximage, slot, pixel, xOff, 
                                 bbox.yMax-slot->top);
    xOff += slot->root.advance.x>>16;
  }
  // send the XImage to the display
  XPutImage(dpy, GDK_WINDOW_XWINDOW(aSurface->GetDrawable()),
  ...

-- 
Brian Stell
mailto:address@hidden