Roll harfbuzz-ng to 1.0.5

third_party/harfbuzz-ng/src/hb-ft.cc

 /*
  * Copyright © 2009  Red Hat, Inc.
  * Copyright © 2009  Keith Stribley
+ * Copyright © 2015  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
  * all copies of this software.
  *
  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  *
  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
  * Red Hat Author(s): Behdad Esfahbod
+ * Google Author(s): Behdad Esfahbod
  */
 
 #include "hb-private.hh"
 
 #include "hb-ft.h"
 
 #include "hb-font-private.hh"
 
 #include FT_ADVANCES_H
 #include FT_TRUETYPE_TABLES_H
 
 
 
 #ifndef HB_DEBUG_FT
 #define HB_DEBUG_FT (HB_DEBUG+0)
 #endif
 
 
 /* TODO:
  *
  * In general, this file does a fine job of what it's supposed to do.
  * There are, however, things that need more work:
  *
- *   - We don't handle any load_flags.  That definitely has API implications. :(
- *     I believe hb_ft_font_create() should take load_flags input.
- *     In particular, FT_Get_Advance() without the NO_HINTING flag seems to be
- *     buggy.
+ *   - I remember seeing FT_Get_Advance() without the NO_HINTING flag to be buggy.
+ *     Have not investigated.
  *
- *     FreeType works in 26.6 mode.  Clients can decide to use that mode, and everything
+ *   - FreeType works in 26.6 mode.  Clients can decide to use that mode, and everything
  *     would work fine.  However, we also abuse this API for performing in font-space,
  *     but don't pass the correct flags to FreeType.  We just abuse the no-hinting mode
  *     for that, such that no rounding etc happens.  As such, we don't set ppem, and
- *     pass NO_HINTING around.  This seems to work best, until we go ahead and add a full
- *     load_flags API.
+ *     pass NO_HINTING as load_flags.  Would be much better to use NO_SCALE, and scale
+ *     ourselves, like we do in uniscribe, etc.
  *
  *   - We don't handle / allow for emboldening / obliqueing.
  *
  *   - In the future, we should add constructors to create fonts in font space?
  *
  *   - FT_Load_Glyph() is exteremely costly.  Do something about it?
  */
 
 
+struct hb_ft_font_t
+{
+  FT_Face ft_face;
+  int load_flags;
+  bool unref; /* Whether to destroy ft_face when done. */
+};
+
+static hb_ft_font_t *
+_hb_ft_font_create (FT_Face ft_face, bool unref)
+{
+  hb_ft_font_t *ft_font = (hb_ft_font_t *) calloc (1, sizeof (hb_ft_font_t));
+
+  if (unlikely (!ft_font))
+    return NULL;
+
+  ft_font->ft_face = ft_face;
+  ft_font->unref = unref;
+
+  ft_font->load_flags = FT_LOAD_DEFAULT;
+
+  return ft_font;
+}
+
+static void
+_hb_ft_font_destroy (hb_ft_font_t *ft_font)
+{
+  if (ft_font->unref)
+    FT_Done_Face (ft_font->ft_face);
+
+  free (ft_font);
+}
+
+/**
+ * hb_ft_font_set_load_flags:
+ * @font:
+ * @load_flags:
+ *
+ * 
+ *
+ * Since: 1.0.5
+ **/
+void
+hb_ft_font_set_load_flags (hb_font_t *font, int load_flags)
+{
+  if (font->immutable)
+    return;
+
+  if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)
+    return;
+
+  hb_ft_font_t *ft_font = (hb_ft_font_t *) font->user_data;
+
+  ft_font->load_flags = load_flags;
+}
+
+/**
+ * hb_ft_font_get_load_flags:
+ * @font:
+ *
+ * 
+ *
+ * Return value:
+ * Since: 1.0.5
+ **/
+int
+hb_ft_font_get_load_flags (hb_font_t *font)
+{
+  if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)
+    return 0;
+
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font->user_data;
+
+  return ft_font->load_flags;
+}
+
+FT_Face
+hb_ft_font_get_face (hb_font_t *font)
+{
+  if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)
+    return NULL;
+
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font->user_data;
+
+  return ft_font->ft_face;
+}
+
+
+
 static hb_bool_t
 hb_ft_get_glyph (hb_font_t *font HB_UNUSED,
                  void *font_data,
                  hb_codepoint_t unicode,
                  hb_codepoint_t variation_selector,
                  hb_codepoint_t *glyph,
                  void *user_data HB_UNUSED)
 
 {
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
   unsigned int g;
-  FT_Face ft_face = (FT_Face) font_data;
 
   if (likely (!variation_selector))
-    g = FT_Get_Char_Index (ft_face, unicode);
+    g = FT_Get_Char_Index (ft_font->ft_face, unicode);
   else
-    g = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector);
+    g = FT_Face_GetCharVariantIndex (ft_font->ft_face, unicode, variation_selector);
 
   if (unlikely (!g))
     return false;
 
   *glyph = g;
   return true;
 }
 
 static hb_position_t
 hb_ft_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
                            void *font_data,
                            hb_codepoint_t glyph,
                            void *user_data HB_UNUSED)
 {
-  FT_Face ft_face = (FT_Face) font_data;
-  int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
   FT_Fixed v;
 
-  if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
+  if (unlikely (FT_Get_Advance (ft_font->ft_face, glyph, ft_font->load_flags, &v)))
     return 0;
 
   if (font->x_scale < 0)
     v = -v;
 
   return (v + (1<<9)) >> 10;
 }
 
 static hb_position_t
 hb_ft_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
                            void *font_data,
                            hb_codepoint_t glyph,
                            void *user_data HB_UNUSED)
 {
-  FT_Face ft_face = (FT_Face) font_data;
-  int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING | FT_LOAD_VERTICAL_LAYOUT;
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
   FT_Fixed v;
 
-  if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
+  if (unlikely (FT_Get_Advance (ft_font->ft_face, glyph, ft_font->load_flags | FT_LOAD_VERTICAL_LAYOUT, &v)))
     return 0;
 
   if (font->y_scale < 0)
     v = -v;
 
   /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
    * have a Y growing upward.  Hence the extra negation. */
   return (-v + (1<<9)) >> 10;
 }
 
@@ skipping 10 matching lines @@
 }
 
 static hb_bool_t
 hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
                           void *font_data,
                           hb_codepoint_t glyph,
                           hb_position_t *x,
                           hb_position_t *y,
                           void *user_data HB_UNUSED)
 {
-  FT_Face ft_face = (FT_Face) font_data;
-  int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
+  FT_Face ft_face = ft_font->ft_face;
 
-  if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
+  if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
     return false;
 
   /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
    * have a Y growing upward.  Hence the extra negation. */
   *x = ft_face->glyph->metrics.horiBearingX -   ft_face->glyph->metrics.vertBearingX;
   *y = ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY);
 
   if (font->x_scale < 0)
     *x = -*x;
   if (font->y_scale < 0)
     *y = -*y;
 
   return true;
 }
 
 static hb_position_t
 hb_ft_get_glyph_h_kerning (hb_font_t *font,
                            void *font_data,
                            hb_codepoint_t left_glyph,
                            hb_codepoint_t right_glyph,
                            void *user_data HB_UNUSED)
 {
-  FT_Face ft_face = (FT_Face) font_data;
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
   FT_Vector kerningv;
 
   FT_Kerning_Mode mode = font->x_ppem ? FT_KERNING_DEFAULT : FT_KERNING_UNFITTED;
-  if (FT_Get_Kerning (ft_face, left_glyph, right_glyph, mode, &kerningv))
+  if (FT_Get_Kerning (ft_font->ft_face, left_glyph, right_glyph, mode, &kerningv))
     return 0;
 
   return kerningv.x;
 }
 
 static hb_position_t
 hb_ft_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
                            void *font_data HB_UNUSED,
                            hb_codepoint_t top_glyph HB_UNUSED,
                            hb_codepoint_t bottom_glyph HB_UNUSED,
                            void *user_data HB_UNUSED)
 {
   /* FreeType API doesn't support vertical kerning */
   return 0;
 }
 
 static hb_bool_t
 hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,
                          void *font_data,
                          hb_codepoint_t glyph,
                          hb_glyph_extents_t *extents,
                          void *user_data HB_UNUSED)
 {
-  FT_Face ft_face = (FT_Face) font_data;
-  int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
+  FT_Face ft_face = ft_font->ft_face;
 
-  if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
+  if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
     return false;
 
   extents->x_bearing = ft_face->glyph->metrics.horiBearingX;
   extents->y_bearing = ft_face->glyph->metrics.horiBearingY;
   extents->width = ft_face->glyph->metrics.width;
   extents->height = -ft_face->glyph->metrics.height;
   return true;
 }
 
 static hb_bool_t
 hb_ft_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
                                void *font_data,
                                hb_codepoint_t glyph,
                                unsigned int point_index,
                                hb_position_t *x,
                                hb_position_t *y,
                                void *user_data HB_UNUSED)
 {
-  FT_Face ft_face = (FT_Face) font_data;
-  int load_flags = FT_LOAD_DEFAULT;
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
+  FT_Face ft_face = ft_font->ft_face;
 
-  if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
+  if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
       return false;
 
   if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
       return false;
 
   if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points))
       return false;
 
   *x = ft_face->glyph->outline.points[point_index].x;
   *y = ft_face->glyph->outline.points[point_index].y;
 
   return true;
 }
 
 static hb_bool_t
 hb_ft_get_glyph_name (hb_font_t *font HB_UNUSED,
                       void *font_data,
                       hb_codepoint_t glyph,
                       char *name, unsigned int size,
                       void *user_data HB_UNUSED)
 {
-  FT_Face ft_face = (FT_Face) font_data;
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
 
-  hb_bool_t ret = !FT_Get_Glyph_Name (ft_face, glyph, name, size);
+  hb_bool_t ret = !FT_Get_Glyph_Name (ft_font->ft_face, glyph, name, size);
   if (ret && (size && !*name))
     ret = false;
 
   return ret;
 }
 
 static hb_bool_t
 hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED,
                            void *font_data,
                            const char *name, int len, /* -1 means nul-terminated */
                            hb_codepoint_t *glyph,
                            void *user_data HB_UNUSED)
 {
-  FT_Face ft_face = (FT_Face) font_data;
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
+  FT_Face ft_face = ft_font->ft_face;
 
   if (len < 0)
     *glyph = FT_Get_Name_Index (ft_face, (FT_String *) name);
   else {
     /* Make a nul-terminated version. */
     char buf[128];
     len = MIN (len, (int) sizeof (buf) - 1);
     strncpy (buf, name, len);
     buf[len] = '\0';
     *glyph = FT_Get_Name_Index (ft_face, buf);
   }
 
   if (*glyph == 0)
   {
     /* Check whether the given name was actually the name of glyph 0. */
     char buf[128];
     if (!FT_Get_Glyph_Name(ft_face, 0, buf, sizeof (buf)) &&
         len < 0 ? !strcmp (buf, name) : !strncmp (buf, name, len))
       return true;
   }
 
   return *glyph != 0;
 }
 
 
-static hb_font_funcs_t *
-_hb_ft_get_font_funcs (void)
+static void
+_hb_ft_font_set_funcs (hb_font_t *font, FT_Face ft_face, bool unref)
 {
   static const hb_font_funcs_t ft_ffuncs = {
     HB_OBJECT_HEADER_STATIC,
 
     true, /* immutable */
 
     {
 #define HB_FONT_FUNC_IMPLEMENT(name) hb_ft_get_##name,
       HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
 #undef HB_FONT_FUNC_IMPLEMENT
     }
   };
 
-  return const_cast<hb_font_funcs_t *> (&ft_ffuncs);
+  hb_font_set_funcs (font,
+                     const_cast<hb_font_funcs_t *> (&ft_ffuncs),
+                     _hb_ft_font_create (ft_face, unref),
+                     (hb_destroy_func_t) _hb_ft_font_destroy);
 }
 
 
 static hb_blob_t *
 reference_table  (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
 {
   FT_Face ft_face = (FT_Face) user_data;
   FT_Byte *buffer;
   FT_ULong  length = 0;
   FT_Error error;
@@ skipping 18 matching lines @@
 }
 
 /**
  * hb_ft_face_create:
  * @ft_face: (destroy destroy) (scope notified): 
  * @destroy:
  *
  * 
  *
  * Return value: (transfer full): 
- * Since: 1.0
+ * Since: 0.9.2
  **/
 hb_face_t *
 hb_ft_face_create (FT_Face           ft_face,
                    hb_destroy_func_t destroy)
 {
   hb_face_t *face;
 
   if (ft_face->stream->read == NULL) {
     hb_blob_t *blob;
 
@@ skipping 35 matching lines @@
   hb_face_destroy ((hb_face_t *) ft_face->generic.data);
 }
 
 /**
  * hb_ft_face_create_cached:
  * @ft_face: 
  *
  * 
  *
  * Return value: (transfer full): 
- * Since: 1.0
+ * Since: 0.9.2
  **/
 hb_face_t *
 hb_ft_face_create_cached (FT_Face ft_face)
 {
   if (unlikely (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer) hb_ft_face_finalize))
   {
     if (ft_face->generic.finalizer)
       ft_face->generic.finalizer (ft_face);
 
     ft_face->generic.data = hb_ft_face_create (ft_face, NULL);
     ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize;
   }
 
   return hb_face_reference ((hb_face_t *) ft_face->generic.data);
 }
 
-static void
-_do_nothing (void)
-{
-}
-
 
 /**
  * hb_ft_font_create:
  * @ft_face: (destroy destroy) (scope notified): 
  * @destroy:
  *
  * 
  *
  * Return value: (transfer full): 
- * Since: 1.0
+ * Since: 0.9.2
  **/
 hb_font_t *
 hb_ft_font_create (FT_Face           ft_face,
                    hb_destroy_func_t destroy)
 {
   hb_font_t *font;
   hb_face_t *face;
 
   face = hb_ft_face_create (ft_face, destroy);
   font = hb_font_create (face);
   hb_face_destroy (face);
-  hb_font_set_funcs (font,
-                     _hb_ft_get_font_funcs (),
-                     ft_face, (hb_destroy_func_t) _do_nothing);
+  _hb_ft_font_set_funcs (font, ft_face, false);
   hb_font_set_scale (font,
                      (int) (((uint64_t) ft_face->size->metrics.x_scale * (uint64_t) ft_face->units_per_EM + (1<<15)) >> 16),
                      (int) (((uint64_t) ft_face->size->metrics.y_scale * (uint64_t) ft_face->units_per_EM + (1<<15)) >> 16));
 #if 0 /* hb-ft works in no-hinting model */
   hb_font_set_ppem (font,
                     ft_face->size->metrics.x_ppem,
                     ft_face->size->metrics.y_ppem);
 #endif
 
   return font;
@@ skipping 93 matching lines @@
   if (font->x_scale < 0 || font->y_scale < 0)
   {
     FT_Matrix matrix = { font->x_scale < 0 ? -1 : +1, 0,
                           0, font->y_scale < 0 ? -1 : +1};
     FT_Set_Transform (ft_face, &matrix, NULL);
   }
 
   ft_face->generic.data = blob;
   ft_face->generic.finalizer = (FT_Generic_Finalizer) _release_blob;
 
-  hb_font_set_funcs (font,
-                     _hb_ft_get_font_funcs (),
-                     ft_face,
-                     (hb_destroy_func_t) FT_Done_Face);
+  _hb_ft_font_set_funcs (font, ft_face, true);
+  hb_ft_font_set_load_flags (font, FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING);
 }
-
-FT_Face
-hb_ft_font_get_face (hb_font_t *font)
-{
-  if (font->destroy == (hb_destroy_func_t) FT_Done_Face ||
-      font->destroy == (hb_destroy_func_t) _do_nothing)
-    return (FT_Face) font->user_data;
-
-  return NULL;
-}