1 /*
2  * Copyright © 2011,2014  Google, Inc.
3  *
4  *  This is part of HarfBuzz, a text shaping library.
5  *
6  * Permission is hereby granted, without written agreement and without
7  * license or royalty fees, to use, copy, modify, and distribute this
8  * software and its documentation for any purpose, provided that the
9  * above copyright notice and the following two paragraphs appear in
10  * all copies of this software.
11  *
12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16  * DAMAGE.
17  *
18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23  *
24  * Google Author(s): Behdad Esfahbod, Roozbeh Pournader
25  */
26 
27 #include "hb-private.hh"
28 
29 #include "hb-ot.h"
30 
31 #include "hb-font-private.hh"
32 
33 #include "hb-ot-cmap-table.hh"
34 #include "hb-ot-cbdt-table.hh"
35 #include "hb-ot-glyf-table.hh"
36 #include "hb-ot-hmtx-table.hh"
37 #include "hb-ot-kern-table.hh"
38 #include "hb-ot-post-table.hh"
39 
40 
41 struct hb_ot_font_t
42 {
43   OT::cmap::accelerator_t cmap;
44   OT::hmtx::accelerator_t h_metrics;
45   OT::vmtx::accelerator_t v_metrics;
46   OT::hb_lazy_loader_t<OT::glyf::accelerator_t> glyf;
47   OT::hb_lazy_loader_t<OT::CBDT::accelerator_t> cbdt;
48   OT::hb_lazy_loader_t<OT::post::accelerator_t> post;
49   OT::hb_lazy_loader_t<OT::kern::accelerator_t> kern;
50 };
51 
52 
53 static hb_ot_font_t *
_hb_ot_font_create(hb_face_t * face)54 _hb_ot_font_create (hb_face_t *face)
55 {
56   hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t));
57 
58   if (unlikely (!ot_font))
59     return nullptr;
60 
61   ot_font->cmap.init (face);
62   ot_font->h_metrics.init (face);
63   ot_font->v_metrics.init (face, ot_font->h_metrics.ascender - ot_font->h_metrics.descender); /* TODO Can we do this lazily? */
64   ot_font->glyf.init (face);
65   ot_font->cbdt.init (face);
66   ot_font->post.init (face);
67   ot_font->kern.init (face);
68 
69   return ot_font;
70 }
71 
72 static void
_hb_ot_font_destroy(void * data)73 _hb_ot_font_destroy (void *data)
74 {
75   hb_ot_font_t *ot_font = (hb_ot_font_t *) data;
76 
77   ot_font->cmap.fini ();
78   ot_font->h_metrics.fini ();
79   ot_font->v_metrics.fini ();
80   ot_font->glyf.fini ();
81   ot_font->cbdt.fini ();
82   ot_font->post.fini ();
83   ot_font->kern.fini ();
84 
85   free (ot_font);
86 }
87 
88 
89 static hb_bool_t
hb_ot_get_nominal_glyph(hb_font_t * font HB_UNUSED,void * font_data,hb_codepoint_t unicode,hb_codepoint_t * glyph,void * user_data HB_UNUSED)90 hb_ot_get_nominal_glyph (hb_font_t *font HB_UNUSED,
91 			 void *font_data,
92 			 hb_codepoint_t unicode,
93 			 hb_codepoint_t *glyph,
94 			 void *user_data HB_UNUSED)
95 
96 {
97   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
98   return ot_font->cmap.get_nominal_glyph (unicode, glyph);
99 }
100 
101 static hb_bool_t
hb_ot_get_variation_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)102 hb_ot_get_variation_glyph (hb_font_t *font HB_UNUSED,
103 			   void *font_data,
104 			   hb_codepoint_t unicode,
105 			   hb_codepoint_t variation_selector,
106 			   hb_codepoint_t *glyph,
107 			   void *user_data HB_UNUSED)
108 {
109   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
110   return ot_font->cmap.get_variation_glyph (unicode, variation_selector, glyph);
111 }
112 
113 static hb_position_t
hb_ot_get_glyph_h_advance(hb_font_t * font,void * font_data,hb_codepoint_t glyph,void * user_data HB_UNUSED)114 hb_ot_get_glyph_h_advance (hb_font_t *font,
115 			   void *font_data,
116 			   hb_codepoint_t glyph,
117 			   void *user_data HB_UNUSED)
118 {
119   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
120   return font->em_scale_x (ot_font->h_metrics.get_advance (glyph, font));
121 }
122 
123 static hb_position_t
hb_ot_get_glyph_v_advance(hb_font_t * font,void * font_data,hb_codepoint_t glyph,void * user_data HB_UNUSED)124 hb_ot_get_glyph_v_advance (hb_font_t *font,
125 			   void *font_data,
126 			   hb_codepoint_t glyph,
127 			   void *user_data HB_UNUSED)
128 {
129   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
130   return font->em_scale_y (-(int) ot_font->v_metrics.get_advance (glyph, font));
131 }
132 
133 static hb_position_t
hb_ot_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)134 hb_ot_get_glyph_h_kerning (hb_font_t *font,
135 			   void *font_data,
136 			   hb_codepoint_t left_glyph,
137 			   hb_codepoint_t right_glyph,
138 			   void *user_data HB_UNUSED)
139 {
140   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
141   return font->em_scale_x (ot_font->kern->get_h_kerning (left_glyph, right_glyph));
142 }
143 
144 static hb_bool_t
hb_ot_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)145 hb_ot_get_glyph_extents (hb_font_t *font HB_UNUSED,
146 			 void *font_data,
147 			 hb_codepoint_t glyph,
148 			 hb_glyph_extents_t *extents,
149 			 void *user_data HB_UNUSED)
150 {
151   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
152   bool ret = ot_font->glyf->get_extents (glyph, extents);
153   if (!ret)
154     ret = ot_font->cbdt->get_extents (glyph, extents);
155   // TODO Hook up side-bearings variations.
156   extents->x_bearing = font->em_scale_x (extents->x_bearing);
157   extents->y_bearing = font->em_scale_y (extents->y_bearing);
158   extents->width     = font->em_scale_x (extents->width);
159   extents->height    = font->em_scale_y (extents->height);
160   return ret;
161 }
162 
163 static hb_bool_t
hb_ot_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)164 hb_ot_get_glyph_name (hb_font_t *font HB_UNUSED,
165                       void *font_data,
166                       hb_codepoint_t glyph,
167                       char *name, unsigned int size,
168                       void *user_data HB_UNUSED)
169 {
170   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
171   return ot_font->post->get_glyph_name (glyph, name, size);
172 }
173 
174 static hb_bool_t
hb_ot_get_glyph_from_name(hb_font_t * font HB_UNUSED,void * font_data,const char * name,int len,hb_codepoint_t * glyph,void * user_data HB_UNUSED)175 hb_ot_get_glyph_from_name (hb_font_t *font HB_UNUSED,
176                            void *font_data,
177                            const char *name, int len,
178                            hb_codepoint_t *glyph,
179                            void *user_data HB_UNUSED)
180 {
181   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
182   return ot_font->post->get_glyph_from_name (name, len, glyph);
183 }
184 
185 static hb_bool_t
hb_ot_get_font_h_extents(hb_font_t * font HB_UNUSED,void * font_data,hb_font_extents_t * metrics,void * user_data HB_UNUSED)186 hb_ot_get_font_h_extents (hb_font_t *font HB_UNUSED,
187 			  void *font_data,
188 			  hb_font_extents_t *metrics,
189 			  void *user_data HB_UNUSED)
190 {
191   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
192   metrics->ascender = font->em_scale_y (ot_font->h_metrics.ascender);
193   metrics->descender = font->em_scale_y (ot_font->h_metrics.descender);
194   metrics->line_gap = font->em_scale_y (ot_font->h_metrics.line_gap);
195   // TODO Hook up variations.
196   return ot_font->h_metrics.has_font_extents;
197 }
198 
199 static hb_bool_t
hb_ot_get_font_v_extents(hb_font_t * font HB_UNUSED,void * font_data,hb_font_extents_t * metrics,void * user_data HB_UNUSED)200 hb_ot_get_font_v_extents (hb_font_t *font HB_UNUSED,
201 			  void *font_data,
202 			  hb_font_extents_t *metrics,
203 			  void *user_data HB_UNUSED)
204 {
205   const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
206   metrics->ascender = font->em_scale_x (ot_font->v_metrics.ascender);
207   metrics->descender = font->em_scale_x (ot_font->v_metrics.descender);
208   metrics->line_gap = font->em_scale_x (ot_font->v_metrics.line_gap);
209   // TODO Hook up variations.
210   return ot_font->v_metrics.has_font_extents;
211 }
212 
213 static hb_font_funcs_t *static_ot_funcs = nullptr;
214 
215 #ifdef HB_USE_ATEXIT
216 static
free_static_ot_funcs(void)217 void free_static_ot_funcs (void)
218 {
219   hb_font_funcs_destroy (static_ot_funcs);
220 }
221 #endif
222 
223 static hb_font_funcs_t *
_hb_ot_get_font_funcs(void)224 _hb_ot_get_font_funcs (void)
225 {
226 retry:
227   hb_font_funcs_t *funcs = (hb_font_funcs_t *) hb_atomic_ptr_get (&static_ot_funcs);
228 
229   if (unlikely (!funcs))
230   {
231     funcs = hb_font_funcs_create ();
232 
233     hb_font_funcs_set_font_h_extents_func (funcs, hb_ot_get_font_h_extents, nullptr, nullptr);
234     hb_font_funcs_set_font_v_extents_func (funcs, hb_ot_get_font_v_extents, nullptr, nullptr);
235     hb_font_funcs_set_nominal_glyph_func (funcs, hb_ot_get_nominal_glyph, nullptr, nullptr);
236     hb_font_funcs_set_variation_glyph_func (funcs, hb_ot_get_variation_glyph, nullptr, nullptr);
237     hb_font_funcs_set_glyph_h_advance_func (funcs, hb_ot_get_glyph_h_advance, nullptr, nullptr);
238     hb_font_funcs_set_glyph_v_advance_func (funcs, hb_ot_get_glyph_v_advance, nullptr, nullptr);
239     //hb_font_funcs_set_glyph_h_origin_func (funcs, hb_ot_get_glyph_h_origin, nullptr, nullptr);
240     //hb_font_funcs_set_glyph_v_origin_func (funcs, hb_ot_get_glyph_v_origin, nullptr, nullptr);
241     hb_font_funcs_set_glyph_h_kerning_func (funcs, hb_ot_get_glyph_h_kerning, nullptr, nullptr);
242     //hb_font_funcs_set_glyph_v_kerning_func (funcs, hb_ot_get_glyph_v_kerning, nullptr, nullptr);
243     hb_font_funcs_set_glyph_extents_func (funcs, hb_ot_get_glyph_extents, nullptr, nullptr);
244     //hb_font_funcs_set_glyph_contour_point_func (funcs, hb_ot_get_glyph_contour_point, nullptr, nullptr);
245     hb_font_funcs_set_glyph_name_func (funcs, hb_ot_get_glyph_name, nullptr, nullptr);
246     hb_font_funcs_set_glyph_from_name_func (funcs, hb_ot_get_glyph_from_name, nullptr, nullptr);
247 
248     hb_font_funcs_make_immutable (funcs);
249 
250     if (!hb_atomic_ptr_cmpexch (&static_ot_funcs, nullptr, funcs)) {
251       hb_font_funcs_destroy (funcs);
252       goto retry;
253     }
254 
255 #ifdef HB_USE_ATEXIT
256     atexit (free_static_ot_funcs); /* First person registers atexit() callback. */
257 #endif
258   };
259 
260   return funcs;
261 }
262 
263 
264 /**
265  * hb_ot_font_set_funcs:
266  *
267  * Since: 0.9.28
268  **/
269 void
hb_ot_font_set_funcs(hb_font_t * font)270 hb_ot_font_set_funcs (hb_font_t *font)
271 {
272   hb_ot_font_t *ot_font = _hb_ot_font_create (font->face);
273   if (unlikely (!ot_font))
274     return;
275 
276   hb_font_set_funcs (font,
277 		     _hb_ot_get_font_funcs (),
278 		     ot_font,
279 		     _hb_ot_font_destroy);
280 }
281