Re: Emacs text shaping using Harfbuzz

[Paul Eggert <eggert@cs.ucla.edu>]

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The Emacs harfbuzz branch built fine for me on Fedora 29 (no surprise). 
I saw no problems, not that I would catch many (the Arabic I saw 
displayed OK to me, but I don't read Arabic so am not the best person to 
judge).

One minor tweak proposed in the attached patch, for simplicity/clarity 
in the mainstream-Harbuzz code.

I see that Harbuzz is disabled by default by 'configure', and that 
there's an environment variable to disable it at runtime. I propose 
removing the environment variable, and enabling Harfbuzz by default at 
'configure' time (if the Harbuzz libraries are available), as I don't 
see much point in nudging users away from Harfbuzz.

I see there are some FIXMEs and suchlike comments. Will someone be 
working on them?


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diff --git a/src/ftfont.c b/src/ftfont.c
index a645bbf029..47442df0e5 100644
--- a/src/ftfont.c
+++ b/src/ftfont.c
@@ -478,28 +478,27 @@ ftfont_get_otf (struct ftfont_info *ftfont_info)
 
 #ifdef HAVE_HARFBUZZ
 
-#ifndef HAVE_HB_FT_FONT_CREATE_REFERENCED
+# ifndef HAVE_HB_FT_FONT_CREATE_REFERENCED
 static void
 ft_face_destroy (void *data)
 {
-  FT_Done_Face ((FT_Face) data);
+  FT_Done_Face (data);
 }
-#endif
+
+static hb_font_t *
+hb_ft_font_create_referenced (FT_Face face)
+{
+  FT_Reference_Face (face);
+  return hb_ft_font_create (face, ft_face_destroy);
+}
+# endif
 
 static hb_font_t *
 ftfont_get_hb_font (struct ftfont_info *ftfont_info)
 {
   if (! ftfont_info->hb_font)
-    {
-      hb_font_t *hb_font;
-#ifdef HAVE_HB_FT_FONT_CREATE_REFERENCED
-      hb_font = hb_ft_font_create_referenced (ftfont_info->ft_size->face);
-#else
-      FT_Reference_Face (ftfont_info->ft_size->face);
-      hb_font = hb_ft_font_create (ftfont_info->ft_size->face, ft_face_destroy);
-#endif
-      ftfont_info->hb_font = hb_font;
-    }
+    ftfont_info->hb_font
+      = hb_ft_font_create_referenced (ftfont_info->ft_size->face);
   return ftfont_info->hb_font;
 }