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      1 /*
      2  * Copyright  2009  Red Hat, Inc.
      3  * Copyright  2011  Google, Inc.
      4  *
      5  *  This is part of HarfBuzz, a text shaping library.
      6  *
      7  * Permission is hereby granted, without written agreement and without
      8  * license or royalty fees, to use, copy, modify, and distribute this
      9  * software and its documentation for any purpose, provided that the
     10  * above copyright notice and the following two paragraphs appear in
     11  * all copies of this software.
     12  *
     13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
     14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
     15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
     16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
     17  * DAMAGE.
     18  *
     19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
     20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
     21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
     22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
     23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
     24  *
     25  * Red Hat Author(s): Behdad Esfahbod
     26  * Google Author(s): Behdad Esfahbod
     27  */
     28 
     29 #ifndef HB_FONT_PRIVATE_HH
     30 #define HB_FONT_PRIVATE_HH
     31 
     32 #include "hb-private.hh"
     33 
     34 #include "hb-font.h"
     35 #include "hb-object-private.hh"
     36 #include "hb-face-private.hh"
     37 #include "hb-shaper-private.hh"
     38 
     39 
     40 
     41 /*
     42  * hb_font_funcs_t
     43  */
     44 
     45 #define HB_FONT_FUNCS_IMPLEMENT_CALLBACKS \
     46   HB_FONT_FUNC_IMPLEMENT (glyph) \
     47   HB_FONT_FUNC_IMPLEMENT (glyph_h_advance) \
     48   HB_FONT_FUNC_IMPLEMENT (glyph_v_advance) \
     49   HB_FONT_FUNC_IMPLEMENT (glyph_h_origin) \
     50   HB_FONT_FUNC_IMPLEMENT (glyph_v_origin) \
     51   HB_FONT_FUNC_IMPLEMENT (glyph_h_kerning) \
     52   HB_FONT_FUNC_IMPLEMENT (glyph_v_kerning) \
     53   HB_FONT_FUNC_IMPLEMENT (glyph_extents) \
     54   HB_FONT_FUNC_IMPLEMENT (glyph_contour_point) \
     55   HB_FONT_FUNC_IMPLEMENT (glyph_name) \
     56   HB_FONT_FUNC_IMPLEMENT (glyph_from_name) \
     57   /* ^--- Add new callbacks here */
     58 
     59 struct hb_font_funcs_t {
     60   hb_object_header_t header;
     61   ASSERT_POD ();
     62 
     63   hb_bool_t immutable;
     64 
     65   /* Don't access these directly.  Call hb_font_get_*() instead. */
     66 
     67   struct {
     68 #define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_func_t name;
     69     HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
     70 #undef HB_FONT_FUNC_IMPLEMENT
     71   } get;
     72 
     73   struct {
     74 #define HB_FONT_FUNC_IMPLEMENT(name) void *name;
     75     HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
     76 #undef HB_FONT_FUNC_IMPLEMENT
     77   } user_data;
     78 
     79   struct {
     80 #define HB_FONT_FUNC_IMPLEMENT(name) hb_destroy_func_t name;
     81     HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
     82 #undef HB_FONT_FUNC_IMPLEMENT
     83   } destroy;
     84 };
     85 
     86 
     87 
     88 /*
     89  * hb_font_t
     90  */
     91 
     92 struct hb_font_t {
     93   hb_object_header_t header;
     94   ASSERT_POD ();
     95 
     96   hb_bool_t immutable;
     97 
     98   hb_font_t *parent;
     99   hb_face_t *face;
    100 
    101   int x_scale;
    102   int y_scale;
    103 
    104   unsigned int x_ppem;
    105   unsigned int y_ppem;
    106 
    107   hb_font_funcs_t   *klass;
    108   void              *user_data;
    109   hb_destroy_func_t  destroy;
    110 
    111   struct hb_shaper_data_t shaper_data;
    112 
    113 
    114   /* Convert from font-space to user-space */
    115   inline hb_position_t em_scale_x (int16_t v) { return em_scale (v, this->x_scale); }
    116   inline hb_position_t em_scale_y (int16_t v) { return em_scale (v, this->y_scale); }
    117 
    118   /* Convert from parent-font user-space to our user-space */
    119   inline hb_position_t parent_scale_x_distance (hb_position_t v) {
    120     if (unlikely (parent && parent->x_scale != x_scale))
    121       return (hb_position_t) (v * (int64_t) this->x_scale / this->parent->x_scale);
    122     return v;
    123   }
    124   inline hb_position_t parent_scale_y_distance (hb_position_t v) {
    125     if (unlikely (parent && parent->y_scale != y_scale))
    126       return (hb_position_t) (v * (int64_t) this->y_scale / this->parent->y_scale);
    127     return v;
    128   }
    129   inline hb_position_t parent_scale_x_position (hb_position_t v) {
    130     return parent_scale_x_distance (v);
    131   }
    132   inline hb_position_t parent_scale_y_position (hb_position_t v) {
    133     return parent_scale_y_distance (v);
    134   }
    135 
    136   inline void parent_scale_distance (hb_position_t *x, hb_position_t *y) {
    137     *x = parent_scale_x_distance (*x);
    138     *y = parent_scale_y_distance (*y);
    139   }
    140   inline void parent_scale_position (hb_position_t *x, hb_position_t *y) {
    141     *x = parent_scale_x_position (*x);
    142     *y = parent_scale_y_position (*y);
    143   }
    144 
    145 
    146   /* Public getters */
    147 
    148   inline hb_bool_t get_glyph (hb_codepoint_t unicode, hb_codepoint_t variation_selector,
    149 			      hb_codepoint_t *glyph)
    150   {
    151     *glyph = 0;
    152     return klass->get.glyph (this, user_data,
    153 			     unicode, variation_selector, glyph,
    154 			     klass->user_data.glyph);
    155   }
    156 
    157   inline hb_position_t get_glyph_h_advance (hb_codepoint_t glyph)
    158   {
    159     return klass->get.glyph_h_advance (this, user_data,
    160 				       glyph,
    161 				       klass->user_data.glyph_h_advance);
    162   }
    163 
    164   inline hb_position_t get_glyph_v_advance (hb_codepoint_t glyph)
    165   {
    166     return klass->get.glyph_v_advance (this, user_data,
    167 				       glyph,
    168 				       klass->user_data.glyph_v_advance);
    169   }
    170 
    171   inline hb_bool_t get_glyph_h_origin (hb_codepoint_t glyph,
    172 				       hb_position_t *x, hb_position_t *y)
    173   {
    174     *x = *y = 0;
    175     return klass->get.glyph_h_origin (this, user_data,
    176 				      glyph, x, y,
    177 				      klass->user_data.glyph_h_origin);
    178   }
    179 
    180   inline hb_bool_t get_glyph_v_origin (hb_codepoint_t glyph,
    181 				       hb_position_t *x, hb_position_t *y)
    182   {
    183     *x = *y = 0;
    184     return klass->get.glyph_v_origin (this, user_data,
    185 				      glyph, x, y,
    186 				      klass->user_data.glyph_v_origin);
    187   }
    188 
    189   inline hb_position_t get_glyph_h_kerning (hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)
    190   {
    191     return klass->get.glyph_h_kerning (this, user_data,
    192 				       left_glyph, right_glyph,
    193 				       klass->user_data.glyph_h_kerning);
    194   }
    195 
    196   inline hb_position_t get_glyph_v_kerning (hb_codepoint_t top_glyph, hb_codepoint_t bottom_glyph)
    197   {
    198     return klass->get.glyph_v_kerning (this, user_data,
    199 				       top_glyph, bottom_glyph,
    200 				       klass->user_data.glyph_v_kerning);
    201   }
    202 
    203   inline hb_bool_t get_glyph_extents (hb_codepoint_t glyph,
    204 				      hb_glyph_extents_t *extents)
    205   {
    206     memset (extents, 0, sizeof (*extents));
    207     return klass->get.glyph_extents (this, user_data,
    208 				     glyph,
    209 				     extents,
    210 				     klass->user_data.glyph_extents);
    211   }
    212 
    213   inline hb_bool_t get_glyph_contour_point (hb_codepoint_t glyph, unsigned int point_index,
    214 					    hb_position_t *x, hb_position_t *y)
    215   {
    216     *x = *y = 0;
    217     return klass->get.glyph_contour_point (this, user_data,
    218 					   glyph, point_index,
    219 					   x, y,
    220 					   klass->user_data.glyph_contour_point);
    221   }
    222 
    223   inline hb_bool_t get_glyph_name (hb_codepoint_t glyph,
    224 				   char *name, unsigned int size)
    225   {
    226     if (size) *name = '\0';
    227     return klass->get.glyph_name (this, user_data,
    228 				  glyph,
    229 				  name, size,
    230 				  klass->user_data.glyph_name);
    231   }
    232 
    233   inline hb_bool_t get_glyph_from_name (const char *name, int len, /* -1 means nul-terminated */
    234 					hb_codepoint_t *glyph)
    235   {
    236     *glyph = 0;
    237     if (len == -1) len = strlen (name);
    238     return klass->get.glyph_from_name (this, user_data,
    239 				       name, len,
    240 				       glyph,
    241 				       klass->user_data.glyph_from_name);
    242   }
    243 
    244 
    245   /* A bit higher-level, and with fallback */
    246 
    247   inline void get_glyph_advance_for_direction (hb_codepoint_t glyph,
    248 					       hb_direction_t direction,
    249 					       hb_position_t *x, hb_position_t *y)
    250   {
    251     if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
    252       *x = get_glyph_h_advance (glyph);
    253       *y = 0;
    254     } else {
    255       *x = 0;
    256       *y = get_glyph_v_advance (glyph);
    257     }
    258   }
    259 
    260   /* Internal only */
    261   inline void guess_v_origin_minus_h_origin (hb_codepoint_t glyph,
    262 					     hb_position_t *x, hb_position_t *y)
    263   {
    264     *x = get_glyph_h_advance (glyph) / 2;
    265 
    266     /* TODO use font_metics.ascent */
    267     *y = y_scale;
    268   }
    269 
    270   inline void get_glyph_origin_for_direction (hb_codepoint_t glyph,
    271 					      hb_direction_t direction,
    272 					      hb_position_t *x, hb_position_t *y)
    273   {
    274     if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))
    275     {
    276       if (!get_glyph_h_origin (glyph, x, y) &&
    277 	   get_glyph_v_origin (glyph, x, y))
    278       {
    279 	hb_position_t dx, dy;
    280 	guess_v_origin_minus_h_origin (glyph, &dx, &dy);
    281 	*x -= dx; *y -= dy;
    282       }
    283     }
    284     else
    285     {
    286       if (!get_glyph_v_origin (glyph, x, y) &&
    287 	   get_glyph_h_origin (glyph, x, y))
    288       {
    289 	hb_position_t dx, dy;
    290 	guess_v_origin_minus_h_origin (glyph, &dx, &dy);
    291 	*x += dx; *y += dy;
    292       }
    293     }
    294   }
    295 
    296   inline void add_glyph_origin_for_direction (hb_codepoint_t glyph,
    297 					      hb_direction_t direction,
    298 					      hb_position_t *x, hb_position_t *y)
    299   {
    300     hb_position_t origin_x, origin_y;
    301 
    302     get_glyph_origin_for_direction (glyph, direction, &origin_x, &origin_y);
    303 
    304     *x += origin_x;
    305     *y += origin_y;
    306   }
    307 
    308   inline void subtract_glyph_origin_for_direction (hb_codepoint_t glyph,
    309 						   hb_direction_t direction,
    310 						   hb_position_t *x, hb_position_t *y)
    311   {
    312     hb_position_t origin_x, origin_y;
    313 
    314     get_glyph_origin_for_direction (glyph, direction, &origin_x, &origin_y);
    315 
    316     *x -= origin_x;
    317     *y -= origin_y;
    318   }
    319 
    320   inline void get_glyph_kerning_for_direction (hb_codepoint_t first_glyph, hb_codepoint_t second_glyph,
    321 					       hb_direction_t direction,
    322 					       hb_position_t *x, hb_position_t *y)
    323   {
    324     if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
    325       *x = get_glyph_h_kerning (first_glyph, second_glyph);
    326       *y = 0;
    327     } else {
    328       *x = 0;
    329       *y = get_glyph_v_kerning (first_glyph, second_glyph);
    330     }
    331   }
    332 
    333   inline hb_bool_t get_glyph_extents_for_origin (hb_codepoint_t glyph,
    334 						 hb_direction_t direction,
    335 						 hb_glyph_extents_t *extents)
    336   {
    337     hb_bool_t ret = get_glyph_extents (glyph, extents);
    338 
    339     if (ret)
    340       subtract_glyph_origin_for_direction (glyph, direction, &extents->x_bearing, &extents->y_bearing);
    341 
    342     return ret;
    343   }
    344 
    345   inline hb_bool_t get_glyph_contour_point_for_origin (hb_codepoint_t glyph, unsigned int point_index,
    346 						       hb_direction_t direction,
    347 						       hb_position_t *x, hb_position_t *y)
    348   {
    349     hb_bool_t ret = get_glyph_contour_point (glyph, point_index, x, y);
    350 
    351     if (ret)
    352       subtract_glyph_origin_for_direction (glyph, direction, x, y);
    353 
    354     return ret;
    355   }
    356 
    357   /* Generates gidDDD if glyph has no name. */
    358   inline void
    359   glyph_to_string (hb_codepoint_t glyph,
    360 		   char *s, unsigned int size)
    361   {
    362     if (get_glyph_name (glyph, s, size)) return;
    363 
    364     if (size && snprintf (s, size, "gid%u", glyph) < 0)
    365       *s = '\0';
    366   }
    367 
    368   /* Parses gidDDD and uniUUUU strings automatically. */
    369   inline hb_bool_t
    370   glyph_from_string (const char *s, int len, /* -1 means nul-terminated */
    371 		     hb_codepoint_t *glyph)
    372   {
    373     if (get_glyph_from_name (s, len, glyph)) return true;
    374 
    375     if (len == -1) len = strlen (s);
    376 
    377     /* Straight glyph index. */
    378     if (hb_codepoint_parse (s, len, 10, glyph))
    379       return true;
    380 
    381     if (len > 3)
    382     {
    383       /* gidDDD syntax for glyph indices. */
    384       if (0 == strncmp (s, "gid", 3) &&
    385 	  hb_codepoint_parse (s + 3, len - 3, 10, glyph))
    386 	return true;
    387 
    388       /* uniUUUU and other Unicode character indices. */
    389       hb_codepoint_t unichar;
    390       if (0 == strncmp (s, "uni", 3) &&
    391 	  hb_codepoint_parse (s + 3, len - 3, 16, &unichar) &&
    392 	  get_glyph (unichar, 0, glyph))
    393 	return true;
    394     }
    395 
    396     return false;
    397   }
    398 
    399   private:
    400   inline hb_position_t em_scale (int16_t v, int scale) { return (hb_position_t) (v * (int64_t) scale / face->get_upem ()); }
    401 };
    402 
    403 #define HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS
    404 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_PROTOTYPE(shaper, font);
    405 #include "hb-shaper-list.hh"
    406 #undef HB_SHAPER_IMPLEMENT
    407 #undef HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS
    408 
    409 
    410 #endif /* HB_FONT_PRIVATE_HH */
    411