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-hhea-table.hh"
35#include "hb-ot-hmtx-table.hh"
36
37
38struct hb_ot_face_metrics_accelerator_t
39{
40  unsigned int num_metrics;
41  unsigned int num_advances;
42  unsigned int default_advance;
43  const OT::_mtx *table;
44  hb_blob_t *blob;
45
46  inline void init (hb_face_t *face,
47		    hb_tag_t _hea_tag, hb_tag_t _mtx_tag,
48		    unsigned int default_advance)
49  {
50    this->default_advance = default_advance;
51    this->num_metrics = face->get_num_glyphs ();
52
53    hb_blob_t *_hea_blob = OT::Sanitizer<OT::_hea>::sanitize (face->reference_table (_hea_tag));
54    const OT::_hea *_hea = OT::Sanitizer<OT::_hea>::lock_instance (_hea_blob);
55    this->num_advances = _hea->numberOfLongMetrics;
56    hb_blob_destroy (_hea_blob);
57
58    this->blob = OT::Sanitizer<OT::_mtx>::sanitize (face->reference_table (_mtx_tag));
59    if (unlikely (!this->num_advances ||
60		  2 * (this->num_advances + this->num_metrics) < hb_blob_get_length (this->blob)))
61    {
62      this->num_metrics = this->num_advances = 0;
63      hb_blob_destroy (this->blob);
64      this->blob = hb_blob_get_empty ();
65    }
66    this->table = OT::Sanitizer<OT::_mtx>::lock_instance (this->blob);
67  }
68
69  inline void fini (void)
70  {
71    hb_blob_destroy (this->blob);
72  }
73
74  inline unsigned int get_advance (hb_codepoint_t glyph) const
75  {
76    if (unlikely (glyph >= this->num_metrics))
77    {
78      /* If this->num_metrics is zero, it means we don't have the metrics table
79       * for this direction: return one EM.  Otherwise, it means that the glyph
80       * index is out of bound: return zero. */
81      if (this->num_metrics)
82	return 0;
83      else
84	return this->default_advance;
85    }
86
87    if (glyph >= this->num_advances)
88      glyph = this->num_advances - 1;
89
90    return this->table->longMetric[glyph].advance;
91  }
92};
93
94struct hb_ot_face_cmap_accelerator_t
95{
96  const OT::CmapSubtable *table;
97  const OT::CmapSubtable *uvs_table;
98  hb_blob_t *blob;
99
100  inline void init (hb_face_t *face)
101  {
102    this->blob = OT::Sanitizer<OT::cmap>::sanitize (face->reference_table (HB_OT_TAG_cmap));
103    const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (this->blob);
104    const OT::CmapSubtable *subtable = NULL;
105    const OT::CmapSubtable *subtable_uvs = NULL;
106
107    /* 32-bit subtables. */
108    if (!subtable) subtable = cmap->find_subtable (3, 10);
109    if (!subtable) subtable = cmap->find_subtable (0, 6);
110    if (!subtable) subtable = cmap->find_subtable (0, 4);
111    /* 16-bit subtables. */
112    if (!subtable) subtable = cmap->find_subtable (3, 1);
113    if (!subtable) subtable = cmap->find_subtable (0, 3);
114    if (!subtable) subtable = cmap->find_subtable (0, 2);
115    if (!subtable) subtable = cmap->find_subtable (0, 1);
116    if (!subtable) subtable = cmap->find_subtable (0, 0);
117    /* Meh. */
118    if (!subtable) subtable = &OT::Null(OT::CmapSubtable);
119
120    /* UVS subtable. */
121    if (!subtable_uvs) subtable_uvs = cmap->find_subtable (0, 5);
122    /* Meh. */
123    if (!subtable_uvs) subtable_uvs = &OT::Null(OT::CmapSubtable);
124
125    this->table = subtable;
126    this->uvs_table = subtable_uvs;
127  }
128
129  inline void fini (void)
130  {
131    hb_blob_destroy (this->blob);
132  }
133
134  inline bool get_glyph (hb_codepoint_t  unicode,
135			 hb_codepoint_t  variation_selector,
136			 hb_codepoint_t *glyph) const
137  {
138    if (unlikely (variation_selector))
139    {
140      switch (this->uvs_table->get_glyph_variant (unicode,
141						  variation_selector,
142						  glyph))
143      {
144	case OT::GLYPH_VARIANT_NOT_FOUND:	return false;
145	case OT::GLYPH_VARIANT_FOUND:		return true;
146	case OT::GLYPH_VARIANT_USE_DEFAULT:	break;
147      }
148    }
149
150    return this->table->get_glyph (unicode, glyph);
151  }
152};
153
154
155struct hb_ot_font_t
156{
157  hb_ot_face_cmap_accelerator_t cmap;
158  hb_ot_face_metrics_accelerator_t h_metrics;
159  hb_ot_face_metrics_accelerator_t v_metrics;
160};
161
162
163static hb_ot_font_t *
164_hb_ot_font_create (hb_font_t *font)
165{
166  hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t));
167  hb_face_t *face = font->face;
168
169  if (unlikely (!ot_font))
170    return NULL;
171
172  unsigned int upem = face->get_upem ();
173
174  ot_font->cmap.init (face);
175  ot_font->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, upem>>1);
176  ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, upem); /* TODO Can we do this lazily? */
177
178  return ot_font;
179}
180
181static void
182_hb_ot_font_destroy (hb_ot_font_t *ot_font)
183{
184  ot_font->cmap.fini ();
185  ot_font->h_metrics.fini ();
186  ot_font->v_metrics.fini ();
187
188  free (ot_font);
189}
190
191
192static hb_bool_t
193hb_ot_get_glyph (hb_font_t *font HB_UNUSED,
194		 void *font_data,
195		 hb_codepoint_t unicode,
196		 hb_codepoint_t variation_selector,
197		 hb_codepoint_t *glyph,
198		 void *user_data HB_UNUSED)
199
200{
201  const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
202  return ot_font->cmap.get_glyph (unicode, variation_selector, glyph);
203}
204
205static hb_position_t
206hb_ot_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
207			   void *font_data,
208			   hb_codepoint_t glyph,
209			   void *user_data HB_UNUSED)
210{
211  const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
212  return font->em_scale_x (ot_font->h_metrics.get_advance (glyph));
213}
214
215static hb_position_t
216hb_ot_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
217			   void *font_data,
218			   hb_codepoint_t glyph,
219			   void *user_data HB_UNUSED)
220{
221  const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
222  return font->em_scale_y (-ot_font->v_metrics.get_advance (glyph));
223}
224
225static hb_bool_t
226hb_ot_get_glyph_h_origin (hb_font_t *font HB_UNUSED,
227			  void *font_data HB_UNUSED,
228			  hb_codepoint_t glyph HB_UNUSED,
229			  hb_position_t *x HB_UNUSED,
230			  hb_position_t *y HB_UNUSED,
231			  void *user_data HB_UNUSED)
232{
233  /* We always work in the horizontal coordinates. */
234  return true;
235}
236
237static hb_bool_t
238hb_ot_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
239			  void *font_data,
240			  hb_codepoint_t glyph,
241			  hb_position_t *x,
242			  hb_position_t *y,
243			  void *user_data HB_UNUSED)
244{
245  /* TODO */
246  return false;
247}
248
249static hb_position_t
250hb_ot_get_glyph_h_kerning (hb_font_t *font,
251			   void *font_data,
252			   hb_codepoint_t left_glyph,
253			   hb_codepoint_t right_glyph,
254			   void *user_data HB_UNUSED)
255{
256  /* TODO */
257  return 0;
258}
259
260static hb_position_t
261hb_ot_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
262			   void *font_data HB_UNUSED,
263			   hb_codepoint_t top_glyph HB_UNUSED,
264			   hb_codepoint_t bottom_glyph HB_UNUSED,
265			   void *user_data HB_UNUSED)
266{
267  /* OpenType doesn't have vertical-kerning other than GPOS. */
268  return 0;
269}
270
271static hb_bool_t
272hb_ot_get_glyph_extents (hb_font_t *font HB_UNUSED,
273			 void *font_data,
274			 hb_codepoint_t glyph,
275			 hb_glyph_extents_t *extents,
276			 void *user_data HB_UNUSED)
277{
278  /* TODO */
279  return false;
280}
281
282static hb_bool_t
283hb_ot_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
284			       void *font_data,
285			       hb_codepoint_t glyph,
286			       unsigned int point_index,
287			       hb_position_t *x,
288			       hb_position_t *y,
289			       void *user_data HB_UNUSED)
290{
291  /* TODO */
292  return false;
293}
294
295static hb_bool_t
296hb_ot_get_glyph_name (hb_font_t *font HB_UNUSED,
297		      void *font_data,
298		      hb_codepoint_t glyph,
299		      char *name, unsigned int size,
300		      void *user_data HB_UNUSED)
301{
302  /* TODO */
303  return false;
304}
305
306static hb_bool_t
307hb_ot_get_glyph_from_name (hb_font_t *font HB_UNUSED,
308			   void *font_data,
309			   const char *name, int len, /* -1 means nul-terminated */
310			   hb_codepoint_t *glyph,
311			   void *user_data HB_UNUSED)
312{
313  /* TODO */
314  return false;
315}
316
317
318static hb_font_funcs_t *
319_hb_ot_get_font_funcs (void)
320{
321  static const hb_font_funcs_t ot_ffuncs = {
322    HB_OBJECT_HEADER_STATIC,
323
324    true, /* immutable */
325
326    {
327#define HB_FONT_FUNC_IMPLEMENT(name) hb_ot_get_##name,
328      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
329#undef HB_FONT_FUNC_IMPLEMENT
330    }
331  };
332
333  return const_cast<hb_font_funcs_t *> (&ot_ffuncs);
334}
335
336
337void
338hb_ot_font_set_funcs (hb_font_t *font)
339{
340  hb_ot_font_t *ot_font = _hb_ot_font_create (font);
341  if (unlikely (!ot_font))
342    return;
343
344  hb_font_set_funcs (font,
345		     _hb_ot_get_font_funcs (),
346		     ot_font,
347		     (hb_destroy_func_t) _hb_ot_font_destroy);
348}
349