hb-ft.c

   1 // C99 port from c++ is protected by a GNU Lesser GPLv3
   2 // Copyright © 2013 Sylvain BERTRAND <sylvain.bertrand@gmail.com>
   3 //                                   <sylware@legeek.net>
   4 #include <stdlib.h>
   5
   6 #include <ft2build.h>
   7 #include FT_FREETYPE_H
   8 #include FT_TRUETYPE_TABLES_H
   9
  10 #include "hb.h"
  11 #include "hb-private.h"
  12 #include "hb-atomic-private.h"
  13 #include "hb-ft.h"
  14 #include "hb-shaper-private.h"
  15 #include "hb-face-private.h"
  16
  17 static hb_blob_t *
  18 reference_table(hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
  19 {
  20   FT_Face ft_face = (FT_Face)user_data;
  21   FT_Byte *buffer;
  22   FT_ULong length = 0;
  23   FT_Error error;
  24
  25   //Note: FreeType like HarfBuzz uses the NONE tag for fetching the entire blob
  26
  27   error = FT_Load_Sfnt_Table(ft_face, tag, 0, NULL, &length);
  28   if (error)
  29     return NULL;
  30
  31   buffer = (FT_Byte*)malloc(length);
  32   if (buffer == NULL)
  33     return NULL;
  34
  35   error = FT_Load_Sfnt_Table(ft_face, tag, 0, buffer, &length);
  36   if (error)
  37     return NULL;
  38
  39   return hb_blob_create((const char*)buffer,
  40                         length,
  41                         HB_MEMORY_MODE_WRITABLE,
  42                         buffer,
  43                         free);
  44 }
  45
  46 hb_face_t *
  47 hb_ft_face_create(FT_Face ft_face, hb_destroy_func_t destroy)
  48 {
  49   hb_face_t *face;
  50
  51   if (ft_face->stream->read == NULL) {
  52     hb_blob_t *blob;
  53
  54     blob = hb_blob_create((const char*)ft_face->stream->base,
  55                           (unsigned)ft_face->stream->size,
  56                           //TODO: We assume that it's mmap()'ed, but FreeType
  57                           //code suggests that there are cases we reach here
  58                           //but font is not mmapped.  For example, when mmap()
  59                           //fails.  No idea how to deal with it better here.
  60                           HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE,
  61                           ft_face, destroy);
  62     face = hb_face_create(blob, ft_face->face_index);
  63     hb_blob_destroy(blob);
  64   } else {
  65     face = hb_face_create_for_tables(reference_table, ft_face, destroy);
  66   }
  67
  68   hb_face_set_index(face, ft_face->face_index);
  69   hb_face_set_upem(face, ft_face->units_per_EM);
  70   return face;
  71 }
  72
  73 static void
  74 hb_ft_face_finalize(FT_Face ft_face)
  75 {
  76   hb_face_destroy((hb_face_t*)ft_face->generic.data);
  77 }
  78
  79 hb_face_t *
  80 hb_ft_face_create_cached(FT_Face ft_face)
  81 {
  82   if (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer)hb_ft_face_finalize) {
  83     if (ft_face->generic.finalizer)
  84       ft_face->generic.finalizer(ft_face);
  85
  86     ft_face->generic.data = hb_ft_face_create(ft_face, NULL);
  87     ft_face->generic.finalizer = (FT_Generic_Finalizer)hb_ft_face_finalize;
  88   }
  89   return hb_face_reference((hb_face_t*)ft_face->generic.data);
  90 }