michael@0: /*
michael@0:  * Copyright © 2009  Red Hat, Inc.
michael@0:  * Copyright © 2009  Keith Stribley
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Red Hat Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #include "hb-private.hh"
michael@0: 
michael@0: #include "hb-ft.h"
michael@0: 
michael@0: #include "hb-font-private.hh"
michael@0: 
michael@0: #include FT_ADVANCES_H
michael@0: #include FT_TRUETYPE_TABLES_H
michael@0: 
michael@0: 
michael@0: 
michael@0: #ifndef HB_DEBUG_FT
michael@0: #define HB_DEBUG_FT (HB_DEBUG+0)
michael@0: #endif
michael@0: 
michael@0: 
michael@0: /* TODO:
michael@0:  *
michael@0:  * In general, this file does a fine job of what it's supposed to do.
michael@0:  * There are, however, things that need more work:
michael@0:  *
michael@0:  *   - We don't handle any load_flags.  That definitely has API implications. :(
michael@0:  *     I believe hb_ft_font_create() should take load_flags input.
michael@0:  *     In particular, FT_Get_Advance() without the NO_HINTING flag seems to be
michael@0:  *     buggy.
michael@0:  *
michael@0:  *   - We don't handle / allow for emboldening / obliqueing.
michael@0:  *
michael@0:  *   - In the future, we should add constructors to create fonts in font space?
michael@0:  *
michael@0:  *   - FT_Load_Glyph() is exteremely costly.  Do something about it?
michael@0:  */
michael@0: 
michael@0: 
michael@0: static hb_bool_t
michael@0: hb_ft_get_glyph (hb_font_t *font HB_UNUSED,
michael@0: 		 void *font_data,
michael@0: 		 hb_codepoint_t unicode,
michael@0: 		 hb_codepoint_t variation_selector,
michael@0: 		 hb_codepoint_t *glyph,
michael@0: 		 void *user_data HB_UNUSED)
michael@0: 
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0: 
michael@0: #ifdef HAVE_FT_FACE_GETCHARVARIANTINDEX
michael@0:   if (unlikely (variation_selector)) {
michael@0:     *glyph = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector);
michael@0:     return *glyph != 0;
michael@0:   }
michael@0: #endif
michael@0: 
michael@0:   *glyph = FT_Get_Char_Index (ft_face, unicode);
michael@0:   return *glyph != 0;
michael@0: }
michael@0: 
michael@0: static hb_position_t
michael@0: hb_ft_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
michael@0: 			   void *font_data,
michael@0: 			   hb_codepoint_t glyph,
michael@0: 			   void *user_data HB_UNUSED)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0:   int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
michael@0:   FT_Fixed v;
michael@0: 
michael@0:   if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
michael@0:     return 0;
michael@0: 
michael@0:   return (v + (1<<9)) >> 10;
michael@0: }
michael@0: 
michael@0: static hb_position_t
michael@0: hb_ft_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
michael@0: 			   void *font_data,
michael@0: 			   hb_codepoint_t glyph,
michael@0: 			   void *user_data HB_UNUSED)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0:   int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING | FT_LOAD_VERTICAL_LAYOUT;
michael@0:   FT_Fixed v;
michael@0: 
michael@0:   if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
michael@0:     return 0;
michael@0: 
michael@0:   /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
michael@0:    * have a Y growing upward.  Hence the extra negation. */
michael@0:   return (-v + (1<<9)) >> 10;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: hb_ft_get_glyph_h_origin (hb_font_t *font HB_UNUSED,
michael@0: 			  void *font_data HB_UNUSED,
michael@0: 			  hb_codepoint_t glyph HB_UNUSED,
michael@0: 			  hb_position_t *x HB_UNUSED,
michael@0: 			  hb_position_t *y HB_UNUSED,
michael@0: 			  void *user_data HB_UNUSED)
michael@0: {
michael@0:   /* We always work in the horizontal coordinates. */
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
michael@0: 			  void *font_data,
michael@0: 			  hb_codepoint_t glyph,
michael@0: 			  hb_position_t *x,
michael@0: 			  hb_position_t *y,
michael@0: 			  void *user_data HB_UNUSED)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0:   int load_flags = FT_LOAD_DEFAULT;
michael@0: 
michael@0:   if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
michael@0:     return false;
michael@0: 
michael@0:   /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
michael@0:    * have a Y growing upward.  Hence the extra negation. */
michael@0:   *x = ft_face->glyph->metrics.horiBearingX -   ft_face->glyph->metrics.vertBearingX;
michael@0:   *y = ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY);
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static hb_position_t
michael@0: hb_ft_get_glyph_h_kerning (hb_font_t *font,
michael@0: 			   void *font_data,
michael@0: 			   hb_codepoint_t left_glyph,
michael@0: 			   hb_codepoint_t right_glyph,
michael@0: 			   void *user_data HB_UNUSED)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0:   FT_Vector kerningv;
michael@0: 
michael@0:   FT_Kerning_Mode mode = font->x_ppem ? FT_KERNING_DEFAULT : FT_KERNING_UNFITTED;
michael@0:   if (FT_Get_Kerning (ft_face, left_glyph, right_glyph, mode, &kerningv))
michael@0:     return 0;
michael@0: 
michael@0:   return kerningv.x;
michael@0: }
michael@0: 
michael@0: static hb_position_t
michael@0: hb_ft_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
michael@0: 			   void *font_data HB_UNUSED,
michael@0: 			   hb_codepoint_t top_glyph HB_UNUSED,
michael@0: 			   hb_codepoint_t bottom_glyph HB_UNUSED,
michael@0: 			   void *user_data HB_UNUSED)
michael@0: {
michael@0:   /* FreeType API doesn't support vertical kerning */
michael@0:   return 0;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,
michael@0: 			 void *font_data,
michael@0: 			 hb_codepoint_t glyph,
michael@0: 			 hb_glyph_extents_t *extents,
michael@0: 			 void *user_data HB_UNUSED)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0:   int load_flags = FT_LOAD_DEFAULT;
michael@0: 
michael@0:   if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
michael@0:     return false;
michael@0: 
michael@0:   extents->x_bearing = ft_face->glyph->metrics.horiBearingX;
michael@0:   extents->y_bearing = ft_face->glyph->metrics.horiBearingY;
michael@0:   extents->width = ft_face->glyph->metrics.width;
michael@0:   extents->height = -ft_face->glyph->metrics.height;
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: hb_ft_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
michael@0: 			       void *font_data,
michael@0: 			       hb_codepoint_t glyph,
michael@0: 			       unsigned int point_index,
michael@0: 			       hb_position_t *x,
michael@0: 			       hb_position_t *y,
michael@0: 			       void *user_data HB_UNUSED)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0:   int load_flags = FT_LOAD_DEFAULT;
michael@0: 
michael@0:   if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
michael@0:       return false;
michael@0: 
michael@0:   if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
michael@0:       return false;
michael@0: 
michael@0:   if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points))
michael@0:       return false;
michael@0: 
michael@0:   *x = ft_face->glyph->outline.points[point_index].x;
michael@0:   *y = ft_face->glyph->outline.points[point_index].y;
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: hb_ft_get_glyph_name (hb_font_t *font HB_UNUSED,
michael@0: 		      void *font_data,
michael@0: 		      hb_codepoint_t glyph,
michael@0: 		      char *name, unsigned int size,
michael@0: 		      void *user_data HB_UNUSED)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0: 
michael@0:   hb_bool_t ret = !FT_Get_Glyph_Name (ft_face, glyph, name, size);
michael@0:   if (ret && (size && !*name))
michael@0:     ret = false;
michael@0: 
michael@0:   return ret;
michael@0: }
michael@0: 
michael@0: static hb_bool_t
michael@0: hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED,
michael@0: 			   void *font_data,
michael@0: 			   const char *name, int len, /* -1 means nul-terminated */
michael@0: 			   hb_codepoint_t *glyph,
michael@0: 			   void *user_data HB_UNUSED)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) font_data;
michael@0: 
michael@0:   if (len < 0)
michael@0:     *glyph = FT_Get_Name_Index (ft_face, (FT_String *) name);
michael@0:   else {
michael@0:     /* Make a nul-terminated version. */
michael@0:     char buf[128];
michael@0:     len = MIN (len, (int) sizeof (buf) - 1);
michael@0:     strncpy (buf, name, len);
michael@0:     buf[len] = '\0';
michael@0:     *glyph = FT_Get_Name_Index (ft_face, buf);
michael@0:   }
michael@0: 
michael@0:   if (*glyph == 0)
michael@0:   {
michael@0:     /* Check whether the given name was actually the name of glyph 0. */
michael@0:     char buf[128];
michael@0:     if (!FT_Get_Glyph_Name(ft_face, 0, buf, sizeof (buf)) &&
michael@0:         len < 0 ? !strcmp (buf, name) : !strncmp (buf, name, len))
michael@0:       return true;
michael@0:   }
michael@0: 
michael@0:   return *glyph != 0;
michael@0: }
michael@0: 
michael@0: 
michael@0: static hb_font_funcs_t *
michael@0: _hb_ft_get_font_funcs (void)
michael@0: {
michael@0:   static const hb_font_funcs_t ft_ffuncs = {
michael@0:     HB_OBJECT_HEADER_STATIC,
michael@0: 
michael@0:     true, /* immutable */
michael@0: 
michael@0:     {
michael@0: #define HB_FONT_FUNC_IMPLEMENT(name) hb_ft_get_##name,
michael@0:       HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
michael@0: #undef HB_FONT_FUNC_IMPLEMENT
michael@0:     }
michael@0:   };
michael@0: 
michael@0:   return const_cast<hb_font_funcs_t *> (&ft_ffuncs);
michael@0: }
michael@0: 
michael@0: 
michael@0: static hb_blob_t *
michael@0: reference_table  (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
michael@0: {
michael@0:   FT_Face ft_face = (FT_Face) user_data;
michael@0:   FT_Byte *buffer;
michael@0:   FT_ULong  length = 0;
michael@0:   FT_Error error;
michael@0: 
michael@0:   /* Note: FreeType like HarfBuzz uses the NONE tag for fetching the entire blob */
michael@0: 
michael@0:   error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length);
michael@0:   if (error)
michael@0:     return NULL;
michael@0: 
michael@0:   buffer = (FT_Byte *) malloc (length);
michael@0:   if (buffer == NULL)
michael@0:     return NULL;
michael@0: 
michael@0:   error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length);
michael@0:   if (error)
michael@0:     return NULL;
michael@0: 
michael@0:   return hb_blob_create ((const char *) buffer, length,
michael@0: 			 HB_MEMORY_MODE_WRITABLE,
michael@0: 			 buffer, free);
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * hb_ft_face_create:
michael@0:  * @ft_face: (destroy destroy) (scope notified): 
michael@0:  * @destroy:
michael@0:  *
michael@0:  * 
michael@0:  *
michael@0:  * Return value: (transfer full): 
michael@0:  * Since: 1.0
michael@0:  **/
michael@0: hb_face_t *
michael@0: hb_ft_face_create (FT_Face           ft_face,
michael@0: 		   hb_destroy_func_t destroy)
michael@0: {
michael@0:   hb_face_t *face;
michael@0: 
michael@0:   if (ft_face->stream->read == NULL) {
michael@0:     hb_blob_t *blob;
michael@0: 
michael@0:     blob = hb_blob_create ((const char *) ft_face->stream->base,
michael@0: 			   (unsigned int) ft_face->stream->size,
michael@0: 			   /* TODO: We assume that it's mmap()'ed, but FreeType code
michael@0: 			    * suggests that there are cases we reach here but font is
michael@0: 			    * not mmapped.  For example, when mmap() fails.  No idea
michael@0: 			    * how to deal with it better here. */
michael@0: 			   HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE,
michael@0: 			   ft_face, destroy);
michael@0:     face = hb_face_create (blob, ft_face->face_index);
michael@0:     hb_blob_destroy (blob);
michael@0:   } else {
michael@0:     face = hb_face_create_for_tables (reference_table, ft_face, destroy);
michael@0:   }
michael@0: 
michael@0:   hb_face_set_index (face, ft_face->face_index);
michael@0:   hb_face_set_upem (face, ft_face->units_per_EM);
michael@0: 
michael@0:   return face;
michael@0: }
michael@0: 
michael@0: static void
michael@0: hb_ft_face_finalize (FT_Face ft_face)
michael@0: {
michael@0:   hb_face_destroy ((hb_face_t *) ft_face->generic.data);
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * hb_ft_face_create_cached:
michael@0:  * @ft_face: 
michael@0:  *
michael@0:  * 
michael@0:  *
michael@0:  * Return value: (transfer full): 
michael@0:  * Since: 1.0
michael@0:  **/
michael@0: hb_face_t *
michael@0: hb_ft_face_create_cached (FT_Face ft_face)
michael@0: {
michael@0:   if (unlikely (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer) hb_ft_face_finalize))
michael@0:   {
michael@0:     if (ft_face->generic.finalizer)
michael@0:       ft_face->generic.finalizer (ft_face);
michael@0: 
michael@0:     ft_face->generic.data = hb_ft_face_create (ft_face, NULL);
michael@0:     ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize;
michael@0:   }
michael@0: 
michael@0:   return hb_face_reference ((hb_face_t *) ft_face->generic.data);
michael@0: }
michael@0: 
michael@0: static void
michael@0: _do_nothing (void)
michael@0: {
michael@0: }
michael@0: 
michael@0: 
michael@0: /**
michael@0:  * hb_ft_font_create:
michael@0:  * @ft_face: (destroy destroy) (scope notified): 
michael@0:  * @destroy:
michael@0:  *
michael@0:  * 
michael@0:  *
michael@0:  * Return value: (transfer full): 
michael@0:  * Since: 1.0
michael@0:  **/
michael@0: hb_font_t *
michael@0: hb_ft_font_create (FT_Face           ft_face,
michael@0: 		   hb_destroy_func_t destroy)
michael@0: {
michael@0:   hb_font_t *font;
michael@0:   hb_face_t *face;
michael@0: 
michael@0:   face = hb_ft_face_create (ft_face, destroy);
michael@0:   font = hb_font_create (face);
michael@0:   hb_face_destroy (face);
michael@0:   hb_font_set_funcs (font,
michael@0: 		     _hb_ft_get_font_funcs (),
michael@0: 		     ft_face, (hb_destroy_func_t) _do_nothing);
michael@0:   hb_font_set_scale (font,
michael@0: 		     (int) (((uint64_t) ft_face->size->metrics.x_scale * (uint64_t) ft_face->units_per_EM + (1<<15)) >> 16),
michael@0: 		     (int) (((uint64_t) ft_face->size->metrics.y_scale * (uint64_t) ft_face->units_per_EM + (1<<15)) >> 16));
michael@0:   hb_font_set_ppem (font,
michael@0: 		    ft_face->size->metrics.x_ppem,
michael@0: 		    ft_face->size->metrics.y_ppem);
michael@0: 
michael@0:   return font;
michael@0: }
michael@0: 
michael@0: 
michael@0: /* Thread-safe, lock-free, FT_Library */
michael@0: 
michael@0: static FT_Library ft_library;
michael@0: 
michael@0: static inline
michael@0: void free_ft_library (void)
michael@0: {
michael@0:   FT_Done_FreeType (ft_library);
michael@0: }
michael@0: 
michael@0: static FT_Library
michael@0: get_ft_library (void)
michael@0: {
michael@0: retry:
michael@0:   FT_Library library = (FT_Library) hb_atomic_ptr_get (&ft_library);
michael@0: 
michael@0:   if (unlikely (!library))
michael@0:   {
michael@0:     /* Not found; allocate one. */
michael@0:     if (FT_Init_FreeType (&library))
michael@0:       return NULL;
michael@0: 
michael@0:     if (!hb_atomic_ptr_cmpexch (&ft_library, NULL, library)) {
michael@0:       FT_Done_FreeType (library);
michael@0:       goto retry;
michael@0:     }
michael@0: 
michael@0: #ifdef HAVE_ATEXIT
michael@0:     atexit (free_ft_library); /* First person registers atexit() callback. */
michael@0: #endif
michael@0:   }
michael@0: 
michael@0:   return library;
michael@0: }
michael@0: 
michael@0: static void
michael@0: _release_blob (FT_Face ft_face)
michael@0: {
michael@0:   hb_blob_destroy ((hb_blob_t *) ft_face->generic.data);
michael@0: }
michael@0: 
michael@0: void
michael@0: hb_ft_font_set_funcs (hb_font_t *font)
michael@0: {
michael@0:   hb_blob_t *blob = hb_face_reference_blob (font->face);
michael@0:   unsigned int blob_length;
michael@0:   const char *blob_data = hb_blob_get_data (blob, &blob_length);
michael@0:   if (unlikely (!blob_length))
michael@0:     DEBUG_MSG (FT, font, "Font face has empty blob");
michael@0: 
michael@0:   FT_Face ft_face = NULL;
michael@0:   FT_Error err = FT_New_Memory_Face (get_ft_library (),
michael@0: 				     (const FT_Byte *) blob_data,
michael@0: 				     blob_length,
michael@0: 				     hb_face_get_index (font->face),
michael@0: 				     &ft_face);
michael@0: 
michael@0:   if (unlikely (err)) {
michael@0:     hb_blob_destroy (blob);
michael@0:     DEBUG_MSG (FT, font, "Font face FT_New_Memory_Face() failed");
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   FT_Select_Charmap (ft_face, FT_ENCODING_UNICODE);
michael@0: 
michael@0:   assert (font->y_scale >= 0);
michael@0:   FT_Set_Char_Size (ft_face,
michael@0: 		    font->x_scale, font->y_scale,
michael@0: 		    0, 0);
michael@0: #if 0
michael@0: 		    font->x_ppem * 72 * 64 / font->x_scale,
michael@0: 		    font->y_ppem * 72 * 64 / font->y_scale);
michael@0: #endif
michael@0: 
michael@0:   ft_face->generic.data = blob;
michael@0:   ft_face->generic.finalizer = (FT_Generic_Finalizer) _release_blob;
michael@0: 
michael@0:   hb_font_set_funcs (font,
michael@0: 		     _hb_ft_get_font_funcs (),
michael@0: 		     ft_face,
michael@0: 		     (hb_destroy_func_t) FT_Done_Face);
michael@0: }
michael@0: 
michael@0: FT_Face
michael@0: hb_ft_font_get_face (hb_font_t *font)
michael@0: {
michael@0:   if (font->destroy == (hb_destroy_func_t) FT_Done_Face ||
michael@0:       font->destroy == (hb_destroy_func_t) _do_nothing)
michael@0:     return (FT_Face) font->user_data;
michael@0: 
michael@0:   return NULL;
michael@0: }