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 /*

  * Copyright © 2009  Red Hat, Inc.

  * Copyright © 2009  Keith Stribley

  *

  *  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

  */

 #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.

  *

  *   - 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?

  */

 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)

 {

   FT_Face ft_face = (FT_Face) font_data;

 #ifdef HAVE_FT_FACE_GETCHARVARIANTINDEX

   if (unlikely (variation_selector)) {

     *glyph = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector);

     return *glyph != 0;

   }

 #endif

   *glyph = FT_Get_Char_Index (ft_face, unicode);

   return *glyph != 0;

 }

 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;

   FT_Fixed v;

   if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))

     return 0;

   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;

   FT_Fixed v;

   if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))

     return 0;

   /* 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;

 }

 static hb_bool_t

 hb_ft_get_glyph_h_origin (hb_font_t *font HB_UNUSED,

 			  void *font_data HB_UNUSED,

 			  hb_codepoint_t glyph HB_UNUSED,

 			  hb_position_t *x HB_UNUSED,

 			  hb_position_t *y HB_UNUSED,

 			  void *user_data HB_UNUSED)

 {

   /* We always work in the horizontal coordinates. */

   return true;

 }

 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;

   if (unlikely (FT_Load_Glyph (ft_face, glyph, 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);

   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;

   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))

     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;

   if (unlikely (FT_Load_Glyph (ft_face, glyph, 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;

   if (unlikely (FT_Load_Glyph (ft_face, glyph, 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;

   hb_bool_t ret = !FT_Get_Glyph_Name (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;

   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 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);

 }

 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;

   /* Note: FreeType like HarfBuzz uses the NONE tag for fetching the entire blob */

   error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length);

   if (error)

     return NULL;

   buffer = (FT_Byte *) malloc (length);

   if (buffer == NULL)

     return NULL;

   error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length);

   if (error)

     return NULL;

   return hb_blob_create ((const char *) buffer, length,

 			 HB_MEMORY_MODE_WRITABLE,

 			 buffer, free);

 }

 /**

  * hb_ft_face_create:

  * @ft_face: (destroy destroy) (scope notified): 

  * @destroy:

  *

  * 

  *

  * Return value: (transfer full): 

  * Since: 1.0

  **/

 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;

     blob = hb_blob_create ((const char *) ft_face->stream->base,

 			   (unsigned int) ft_face->stream->size,

 			   /* TODO: We assume that it's mmap()'ed, but FreeType code

 			    * suggests that there are cases we reach here but font is

 			    * not mmapped.  For example, when mmap() fails.  No idea

 			    * how to deal with it better here. */

 			   HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE,

 			   ft_face, destroy);

     face = hb_face_create (blob, ft_face->face_index);

     hb_blob_destroy (blob);

   } else {

     face = hb_face_create_for_tables (reference_table, ft_face, destroy);

   }

   hb_face_set_index (face, ft_face->face_index);

   hb_face_set_upem (face, ft_face->units_per_EM);

   return face;

 }

 static void

 hb_ft_face_finalize (FT_Face ft_face)

 {

   hb_face_destroy ((hb_face_t *) ft_face->generic.data);

 }

 /**

  * hb_ft_face_create_cached:

  * @ft_face: 

  *

  * 

  *

  * Return value: (transfer full): 

  * Since: 1.0

  **/

 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

  **/

 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_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));

   hb_font_set_ppem (font,

 		    ft_face->size->metrics.x_ppem,

 		    ft_face->size->metrics.y_ppem);

   return font;

 }

 /* Thread-safe, lock-free, FT_Library */

 static FT_Library ft_library;

 static inline

 void free_ft_library (void)

 {

   FT_Done_FreeType (ft_library);

 }

 static FT_Library

 get_ft_library (void)

 {

 retry:

   FT_Library library = (FT_Library) hb_atomic_ptr_get (&ft_library);

   if (unlikely (!library))

   {

     /* Not found; allocate one. */

     if (FT_Init_FreeType (&library))

       return NULL;

     if (!hb_atomic_ptr_cmpexch (&ft_library, NULL, library)) {

       FT_Done_FreeType (library);

       goto retry;

     }

 #ifdef HAVE_ATEXIT

     atexit (free_ft_library); /* First person registers atexit() callback. */

 #endif

   }

   return library;

 }

 static void

 _release_blob (FT_Face ft_face)

 {

   hb_blob_destroy ((hb_blob_t *) ft_face->generic.data);

 }

 void

 hb_ft_font_set_funcs (hb_font_t *font)

 {

   hb_blob_t *blob = hb_face_reference_blob (font->face);

   unsigned int blob_length;

   const char *blob_data = hb_blob_get_data (blob, &blob_length);

   if (unlikely (!blob_length))

     DEBUG_MSG (FT, font, "Font face has empty blob");

   FT_Face ft_face = NULL;

   FT_Error err = FT_New_Memory_Face (get_ft_library (),

 				     (const FT_Byte *) blob_data,

 				     blob_length,

 				     hb_face_get_index (font->face),

 				     &ft_face);

   if (unlikely (err)) {

     hb_blob_destroy (blob);

     DEBUG_MSG (FT, font, "Font face FT_New_Memory_Face() failed");

     return;

   }

   FT_Select_Charmap (ft_face, FT_ENCODING_UNICODE);

   assert (font->y_scale >= 0);

   FT_Set_Char_Size (ft_face,

 		    font->x_scale, font->y_scale,

 		    0, 0);

 #if 0

 		    font->x_ppem * 72 * 64 / font->x_scale,

 		    font->y_ppem * 72 * 64 / font->y_scale);

 #endif

   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);

 }

 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;

 }