Re: [ft-devel] PDF text rendering error

[suzuki toshiya]

Attached is my proposal to fix this issue, please try.

In my case (Debian GNU/Linux xpdf-3.02-11), using the
patched freetype library by LD_PRELOAD, xpdf shows
readable result (without patch, the result is unreadable).

Regards,
mpsuzuki

suzuki toshiya wrote:
> Johnson Y. Yan wrote (2012/06/11 16:03):
> > Werner and Toshiya-san,
> >
> > I  put the font as a tricky font to deal with.
> > static const char trick_names[TRICK_NAMES_COUNT]
> >                                  [TRICK_NAMES_MAX_CHARACTERS + 1] =
> >     {
> >       "DFKaiSho-SB",     /* dfkaisb.ttf */
> >       "DFKaiShu",
> >       "DFKai-SB",        /* kaiu.ttf */
> >       "HuaTianKaiTi?",   /* htkt2.ttf */
> >       "HuaTianSongTi?",  /* htst3.ttf */
> >       "MingLiU",         /* mingliu.ttf & mingliu.ttc */
> >       "PMingLiU",        /* mingliu.ttc */
> >       "MingLi43",        /* mingli.ttf */
> >   "BKLGIB+FA"     ---------------------------------------- this is the 
> > embeded font in th document.
> >     };
> > it still render error. .
>
> Including the randomization prefix to the tricky font name list is bad 
> idea.
>
> > I opened the embeded font use font lab, found the gid = 2134 is like 
> > this, please see the attach bitmap,
> > some of lines form a 0 area areas, then fill the area(have no area), 
> > Does freetype made special processing?
> >
> >  
> >
> > Johnson Y. Yan
> >
> >
> >
> > 发件人： Werner LEMBERG
> > 发送时间： 2012-06-11 12:55:42
> > 收件人： yinsen_yan
> > 抄送： freetype-devel; mpsuzuki
> > 主题： Re: PDF text rendering error
> >
> > > Do you mean the font must be rendered use
> > > TT_CONFIG_OPTION_BYTECODE_INTERPRETER?
> > No, the FreeType *library* must be built with it: Edit ftoption.h to
> > set this flag, then recompile.
> > Additionally, hinting must be enabled for this font, this is,
> > FT_LOAD_NO_SCALE doesn't work here.
> > Normally, those steps are (more or less) handled automatically by
> > FreeType, since we maintain a list of `tricky' font like the one you
> > have encountered in the PDF; see file `ttobjs.c'.  The subsetted font
> > in question, however, which identifies itself as
> >   BKLGIB+FA-RoundGothicB
> >   ＦＡ 丸ゴシックＢ and FA-RoundGothicB are trademarks of NEC Office 
> > Systems,Ltd.
> > isn't in this list; for the NEC FA fonts (and others), a second
> > mechanism is used which doesn't work with subsetted fonts.
> > Toshiya-san, any ideas?
> >     Werner
>
>
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diff --git a/src/truetype/ttobjs.c b/src/truetype/ttobjs.c
index 814c713..1f8a768 100644
--- a/src/truetype/ttobjs.c
+++ b/src/truetype/ttobjs.c
@@ -244,7 +244,7 @@
   tt_check_trickyness_sfnt_ids( TT_Face  face )
   {
 #define TRICK_SFNT_IDS_PER_FACE   3
-#define TRICK_SFNT_IDS_NUM_FACES  13
+#define TRICK_SFNT_IDS_NUM_FACES  17
 
     static const tt_sfnt_id_rec sfnt_id[TRICK_SFNT_IDS_NUM_FACES]
                                        [TRICK_SFNT_IDS_PER_FACE] = {
@@ -317,6 +317,26 @@
         { 0x00000000, 0x00000000 }, /* cvt  */
         { 0x0d3de9cb, 0x00000141 }, /* fpgm */
         { 0xd4127766, 0x00002280 }  /* prep */
+      },
+      { /* NEC FA-Gothic, 1996 */
+        { 0x00000000, 0x00000000 }, /* cvt  */
+        { 0x4a692698, 0x000001f0 }, /* fpgm */
+        { 0x340d4346, 0x00001fca }  /* prep */
+      },
+      { /* NEC FA-Minchou, 1996 */
+        { 0x00000000, 0x00000000 }, /* cvt  */
+        { 0xcd34c604, 0x00000166 }, /* fpgm */
+        { 0x6cf31046, 0x000022b0 }  /* prep */
+      },
+      { /* NEC FA-RoundGothicB, 1996 */
+        { 0x00000000, 0x00000000 }, /* cvt  */
+        { 0x5da75315, 0x0000019d }, /* fpgm */
+        { 0x40745a5f, 0x000022e0 }  /* prep */
+      },
+      { /* NEC FA-RoundGothicM, 1996 */
+        { 0x00000000, 0x00000000 }, /* cvt  */
+        { 0xf055fc48, 0x000001c2 }, /* fpgm */
+        { 0x3900ded3, 0x00001e18 }  /* prep */
       }
     };