1/*
2 * Copyright © 2012  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
25 */
26
27#define HB_SHAPER old
28#define hb_old_shaper_face_data_t HB_FaceRec_
29#define hb_old_shaper_font_data_t HB_Font_
30#include "hb-shaper-impl-private.hh"
31
32#include <harfbuzz.h>
33
34
35#ifndef HB_DEBUG_OLD
36#define HB_DEBUG_OLD (HB_DEBUG+0)
37#endif
38
39
40static HB_Script
41hb_old_script_from_script (hb_script_t script)
42{
43  switch ((hb_tag_t) script)
44  {
45    default:
46    case HB_SCRIPT_COMMON:		return HB_Script_Common;
47    case HB_SCRIPT_GREEK:		return HB_Script_Greek;
48    case HB_SCRIPT_CYRILLIC:		return HB_Script_Cyrillic;
49    case HB_SCRIPT_ARMENIAN:		return HB_Script_Armenian;
50    case HB_SCRIPT_HEBREW:		return HB_Script_Hebrew;
51    case HB_SCRIPT_ARABIC:		return HB_Script_Arabic;
52    case HB_SCRIPT_SYRIAC:		return HB_Script_Syriac;
53    case HB_SCRIPT_THAANA:		return HB_Script_Thaana;
54    case HB_SCRIPT_DEVANAGARI:		return HB_Script_Devanagari;
55    case HB_SCRIPT_BENGALI:		return HB_Script_Bengali;
56    case HB_SCRIPT_GURMUKHI:		return HB_Script_Gurmukhi;
57    case HB_SCRIPT_GUJARATI:		return HB_Script_Gujarati;
58    case HB_SCRIPT_ORIYA:		return HB_Script_Oriya;
59    case HB_SCRIPT_TAMIL:		return HB_Script_Tamil;
60    case HB_SCRIPT_TELUGU:		return HB_Script_Telugu;
61    case HB_SCRIPT_KANNADA:		return HB_Script_Kannada;
62    case HB_SCRIPT_MALAYALAM:		return HB_Script_Malayalam;
63    case HB_SCRIPT_SINHALA:		return HB_Script_Sinhala;
64    case HB_SCRIPT_THAI:		return HB_Script_Thai;
65    case HB_SCRIPT_LAO:			return HB_Script_Lao;
66    case HB_SCRIPT_TIBETAN:		return HB_Script_Tibetan;
67    case HB_SCRIPT_MYANMAR:		return HB_Script_Myanmar;
68    case HB_SCRIPT_GEORGIAN:		return HB_Script_Georgian;
69    case HB_SCRIPT_HANGUL:		return HB_Script_Hangul;
70    case HB_SCRIPT_OGHAM:		return HB_Script_Ogham;
71    case HB_SCRIPT_RUNIC:		return HB_Script_Runic;
72    case HB_SCRIPT_KHMER:		return HB_Script_Khmer;
73    case HB_SCRIPT_NKO:			return HB_Script_Nko;
74    case HB_SCRIPT_INHERITED:		return HB_Script_Inherited;
75  }
76}
77
78
79static HB_Bool
80hb_old_convertStringToGlyphIndices (HB_Font old_font,
81				    const HB_UChar16 *string,
82				    hb_uint32 length,
83				    HB_Glyph *glyphs,
84				    hb_uint32 *numGlyphs,
85				    HB_Bool rightToLeft)
86{
87  hb_font_t *font = (hb_font_t *) old_font->userData;
88
89  for (unsigned int i = 0; i < length; i++)
90  {
91    hb_codepoint_t u;
92
93    /* XXX Handle UTF-16.  Ugh */
94    u = string[i];
95
96    if (rightToLeft)
97      u = hb_unicode_funcs_get_default ()->mirroring (u);
98
99    font->get_glyph (u, 0, &u); /* TODO Variation selectors */
100
101    glyphs[i] = u;
102  }
103  *numGlyphs = length; /* XXX */
104
105  return true;
106}
107
108static void
109hb_old_getGlyphAdvances (HB_Font old_font,
110			 const HB_Glyph *glyphs,
111			 hb_uint32 numGlyphs,
112			 HB_Fixed *advances,
113			 int flags /*HB_ShaperFlag*/ HB_UNUSED)
114{
115  hb_font_t *font = (hb_font_t *) old_font->userData;
116
117  for (unsigned int i = 0; i < numGlyphs; i++)
118    advances[i] = font->get_glyph_h_advance (glyphs[i]);
119}
120
121static HB_Bool
122hb_old_canRender (HB_Font old_font,
123		  const HB_UChar16 *string,
124		  hb_uint32 length)
125{
126  return true; /* TODO */
127}
128
129static HB_Error
130hb_old_getPointInOutline (HB_Font old_font,
131			  HB_Glyph glyph,
132			  int flags /*HB_ShaperFlag*/,
133			  hb_uint32 point,
134			  HB_Fixed *xpos,
135			  HB_Fixed *ypos,
136			  hb_uint32 *nPoints)
137{
138  return HB_Err_Ok; /* TODO */
139}
140
141static void
142hb_old_getGlyphMetrics (HB_Font old_font,
143			HB_Glyph glyph,
144			HB_GlyphMetrics *metrics)
145{
146  hb_font_t *font = (hb_font_t *) old_font->userData;
147
148  hb_glyph_extents_t extents;
149
150  font->get_glyph_extents (glyph, &extents);
151
152  metrics->x       = extents.x_bearing;
153  metrics->y       = extents.y_bearing;
154  metrics->width   = extents.width;
155  metrics->height  = extents.height;
156  metrics->xOffset = font->get_glyph_h_advance (glyph);
157  metrics->yOffset = 0;
158}
159
160static HB_Fixed
161hb_old_getFontMetric (HB_Font old_font,
162		      HB_FontMetric metric)
163{
164  hb_font_t *font = (hb_font_t *) old_font->userData;
165
166  switch (metric)
167  {
168    case HB_FontAscent:
169       return font->y_scale; /* XXX We don't have ascent data yet. */
170
171    default:
172      return 0;
173  }
174}
175
176static const HB_FontClass hb_old_font_class = {
177  hb_old_convertStringToGlyphIndices,
178  hb_old_getGlyphAdvances,
179  hb_old_canRender,
180  hb_old_getPointInOutline,
181  hb_old_getGlyphMetrics,
182  hb_old_getFontMetric
183};
184
185
186
187static HB_Error
188table_func (void *font, HB_Tag tag, HB_Byte *buffer, HB_UInt *length)
189{
190  hb_face_t *face = (hb_face_t *) font;
191  hb_blob_t *blob = face->reference_table ((hb_tag_t) tag);
192  unsigned int capacity = *length;
193  *length = hb_blob_get_length (blob);
194  memcpy (buffer, hb_blob_get_data (blob, NULL), MIN (capacity, *length));
195  hb_blob_destroy (blob);
196 return HB_Err_Ok;
197}
198
199
200/*
201 * shaper face data
202 */
203
204hb_old_shaper_face_data_t *
205_hb_old_shaper_face_data_create (hb_face_t *face)
206{
207  return HB_NewFace (face, table_func);
208}
209
210void
211_hb_old_shaper_face_data_destroy (hb_old_shaper_face_data_t *data)
212{
213  HB_FreeFace (data);
214}
215
216
217/*
218 * shaper font data
219 */
220
221hb_old_shaper_font_data_t *
222_hb_old_shaper_font_data_create (hb_font_t *font)
223{
224  HB_FontRec *data = (HB_FontRec *) calloc (1, sizeof (HB_FontRec));
225  if (unlikely (!data)) {
226    DEBUG_MSG (OLD, font, "malloc()ing HB_Font failed");
227    return NULL;
228  }
229
230  data->klass = &hb_old_font_class;
231  data->x_ppem = font->x_ppem;
232  data->y_ppem = font->y_ppem;
233  data->x_scale = font->x_scale; /* XXX */
234  data->y_scale = font->y_scale; /* XXX */
235  data->userData = font;
236
237  return data;
238}
239
240void
241_hb_old_shaper_font_data_destroy (hb_old_shaper_font_data_t *data)
242{
243  free (data);
244}
245
246
247/*
248 * shaper shape_plan data
249 */
250
251struct hb_old_shaper_shape_plan_data_t {};
252
253hb_old_shaper_shape_plan_data_t *
254_hb_old_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
255				       const hb_feature_t *user_features HB_UNUSED,
256				       unsigned int        num_user_features HB_UNUSED)
257{
258  return (hb_old_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
259}
260
261void
262_hb_old_shaper_shape_plan_data_destroy (hb_old_shaper_shape_plan_data_t *data HB_UNUSED)
263{
264}
265
266
267/*
268 * shaper
269 */
270
271hb_bool_t
272_hb_old_shape (hb_shape_plan_t    *shape_plan HB_UNUSED,
273	       hb_font_t          *font,
274	       hb_buffer_t        *buffer,
275	       const hb_feature_t *features,
276	       unsigned int        num_features)
277{
278  hb_face_t *face = font->face;
279  HB_Face old_face = HB_SHAPER_DATA_GET (face);
280  HB_Font old_font = HB_SHAPER_DATA_GET (font);
281
282  bool backward = HB_DIRECTION_IS_BACKWARD (buffer->props.direction);
283
284retry:
285
286  unsigned int scratch_size;
287  char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
288
289#define utf16_index() var1.u32
290  HB_UChar16 *pchars = (HB_UChar16 *) scratch;
291  unsigned int chars_len = 0;
292  for (unsigned int i = 0; i < buffer->len; i++) {
293    hb_codepoint_t c = buffer->info[i].codepoint;
294    buffer->info[i].utf16_index() = chars_len;
295    if (likely (c < 0x10000))
296      pchars[chars_len++] = c;
297    else if (unlikely (c >= 0x110000))
298      pchars[chars_len++] = 0xFFFD;
299    else {
300      pchars[chars_len++] = 0xD800 + ((c - 0x10000) >> 10);
301      pchars[chars_len++] = 0xDC00 + ((c - 0x10000) & ((1 << 10) - 1));
302    }
303  }
304
305
306#define ALLOCATE_ARRAY(Type, name, len) \
307  name = (Type *) scratch; \
308  scratch += (len) * sizeof ((name)[0]); \
309  scratch_size -= (len) * sizeof ((name)[0]);
310
311
312  HB_ShaperItem item = {0};
313
314  ALLOCATE_ARRAY (const HB_UChar16, item.string, chars_len);
315  ALLOCATE_ARRAY (unsigned short, item.log_clusters, chars_len + 2);
316  item.stringLength = chars_len;
317  item.item.pos = 0;
318  item.item.length = item.stringLength;
319  item.item.script = hb_old_script_from_script (buffer->props.script);
320  item.item.bidiLevel = backward ? 1 : 0;
321
322  item.font = old_font;
323  item.face = old_face;
324  item.shaperFlags = 0;
325
326  item.glyphIndicesPresent = false;
327
328  /* TODO Alignment. */
329  unsigned int num_glyphs = scratch_size / (sizeof (HB_Glyph) +
330					    sizeof (HB_GlyphAttributes) +
331					    sizeof (HB_Fixed) +
332					    sizeof (HB_FixedPoint) +
333					    sizeof (uint32_t));
334
335  item.num_glyphs = num_glyphs;
336  ALLOCATE_ARRAY (HB_Glyph, item.glyphs, num_glyphs);
337  ALLOCATE_ARRAY (HB_GlyphAttributes, item.attributes, num_glyphs);
338  ALLOCATE_ARRAY (HB_Fixed, item.advances, num_glyphs);
339  ALLOCATE_ARRAY (HB_FixedPoint, item.offsets, num_glyphs);
340  /* Apparently in some cases the offsets array will not be fully assigned to.
341   * Clear it. */
342  memset (item.offsets, 0, num_glyphs * sizeof (item.offsets[0]));
343  uint32_t *vis_clusters;
344  ALLOCATE_ARRAY (uint32_t, vis_clusters, num_glyphs);
345
346#undef ALLOCATE_ARRAY
347
348  if (!HB_ShapeItem (&item))
349  {
350    if (unlikely (item.num_glyphs > num_glyphs))
351    {
352      buffer->ensure (buffer->allocated * 2);
353      if (buffer->in_error)
354        return false;
355      goto retry;
356    }
357    return false;
358  }
359  num_glyphs = item.num_glyphs;
360
361  /* Ok, we've got everything we need, now compose output buffer,
362   * very, *very*, carefully! */
363
364  /* Calculate visual-clusters.  That's what we ship. */
365  for (unsigned int i = 0; i < num_glyphs; i++)
366    vis_clusters[i] = -1;
367  for (unsigned int i = 0; i < buffer->len; i++) {
368    uint32_t *p = &vis_clusters[item.log_clusters[buffer->info[i].utf16_index()]];
369    *p = MIN (*p, buffer->info[i].cluster);
370  }
371  for (unsigned int i = 1; i < num_glyphs; i++)
372    if (vis_clusters[i] == (uint32_t) -1)
373      vis_clusters[i] = vis_clusters[i - 1];
374
375#undef utf16_index
376
377  buffer->ensure (num_glyphs);
378  if (buffer->in_error)
379    return false;
380
381
382  buffer->len = num_glyphs;
383  hb_glyph_info_t *info = buffer->info;
384  for (unsigned int i = 0; i < num_glyphs; i++)
385  {
386    info[i].codepoint = item.glyphs[i];
387    info[i].cluster = vis_clusters[i];
388
389    info[i].mask = item.advances[i];
390    info[i].var1.u32 = item.offsets[i].x;
391    info[i].var2.u32 = item.offsets[i].y;
392  }
393
394  buffer->clear_positions ();
395
396  for (unsigned int i = 0; i < num_glyphs; ++i) {
397    hb_glyph_info_t *info = &buffer->info[i];
398    hb_glyph_position_t *pos = &buffer->pos[i];
399
400    /* TODO vertical */
401    pos->x_advance = info->mask;
402    pos->x_offset = info->var1.u32;
403    pos->y_offset = info->var2.u32;
404  }
405
406  if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
407    buffer->reverse ();
408
409  return true;
410}
411