hb-coretext.cc revision 027857d0412477fb4427dcb8a8c45287c272e143 
1/*
2 * Copyright © 2012  Mozilla Foundation.
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 * Mozilla Author(s): Jonathan Kew
25 */
26
27#define HB_SHAPER coretext
28#include "hb-shaper-private.hh"
29
30#define GlyphID GlyphID_mac
31#include <ApplicationServices/ApplicationServices.h>
32#undef GlyphID
33
34#include "hb-coretext.h"
35
36#include "hb-font-private.hh"
37#include "hb-buffer-private.hh"
38
39
40#ifndef HB_DEBUG_CORETEXT
41#define HB_DEBUG_CORETEXT (HB_DEBUG+0)
42#endif
43
44
45static hb_user_data_key_t hb_coretext_data_key;
46
47static struct hb_coretext_face_data_t {
48  CGFontRef  cg_font;
49} _hb_coretext_face_data_nil = {0};
50
51static void
52_hb_coretext_face_data_destroy (hb_coretext_face_data_t *data)
53{
54  if (data->cg_font)
55    CFRelease (data->cg_font);
56  free (data);
57}
58
59static void
60release_data (void *info, const void *data, size_t size)
61{
62  assert (hb_blob_get_length ((hb_blob_t *) info) == size &&
63          hb_blob_get_data ((hb_blob_t *) info, NULL) == data);
64
65  hb_blob_destroy ((hb_blob_t *) info);
66}
67
68static hb_coretext_face_data_t *
69_hb_coretext_face_get_data (hb_face_t *face)
70{
71  hb_coretext_face_data_t *data = (hb_coretext_face_data_t *) hb_face_get_user_data (face, &hb_coretext_data_key);
72  if (likely (data)) return data;
73
74  data = (hb_coretext_face_data_t *) calloc (1, sizeof (hb_coretext_face_data_t));
75  if (unlikely (!data))
76    return &_hb_coretext_face_data_nil;
77
78
79  hb_blob_t *blob = hb_face_reference_blob (face);
80  unsigned int blob_length;
81  const char *blob_data = hb_blob_get_data (blob, &blob_length);
82  if (unlikely (!blob_length))
83    DEBUG_MSG (CORETEXT, face, "Face has empty blob");
84
85  CGDataProviderRef provider = CGDataProviderCreateWithData (blob, blob_data, blob_length, &release_data);
86  data->cg_font = CGFontCreateWithDataProvider (provider);
87  CGDataProviderRelease (provider);
88
89  if (unlikely (!data->cg_font))
90    DEBUG_MSG (CORETEXT, face, "Face CGFontCreateWithDataProvider() failed");
91
92
93  if (unlikely (!hb_face_set_user_data (face, &hb_coretext_data_key, data,
94                                        (hb_destroy_func_t) _hb_coretext_face_data_destroy,
95                                        false)))
96  {
97    _hb_coretext_face_data_destroy (data);
98    data = (hb_coretext_face_data_t *) hb_face_get_user_data (face, &hb_coretext_data_key);
99    if (data)
100      return data;
101    else
102      return &_hb_coretext_face_data_nil;
103  }
104
105  return data;
106}
107
108
109static struct hb_coretext_font_data_t {
110  CTFontRef ct_font;
111} _hb_coretext_font_data_nil = {0};
112
113static void
114_hb_coretext_font_data_destroy (hb_coretext_font_data_t *data)
115{
116  if (data->ct_font)
117    CFRelease (data->ct_font);
118  free (data);
119}
120
121static hb_coretext_font_data_t *
122_hb_coretext_font_get_data (hb_font_t *font)
123{
124  hb_coretext_font_data_t *data = (hb_coretext_font_data_t *) hb_font_get_user_data (font, &hb_coretext_data_key);
125  if (likely (data)) return data;
126
127  data = (hb_coretext_font_data_t *) calloc (1, sizeof (hb_coretext_font_data_t));
128  if (unlikely (!data))
129    return &_hb_coretext_font_data_nil;
130
131  hb_coretext_face_data_t *face_data = _hb_coretext_face_get_data (font->face);
132
133  data->ct_font = CTFontCreateWithGraphicsFont (face_data->cg_font, font->y_scale, NULL, NULL);
134  if (unlikely (!data->ct_font))
135    DEBUG_MSG (CORETEXT, font, "Font CTFontCreateWithGraphicsFont() failed");
136
137  if (unlikely (!hb_font_set_user_data (font, &hb_coretext_data_key, data,
138                                        (hb_destroy_func_t) _hb_coretext_font_data_destroy,
139                                        false)))
140  {
141    _hb_coretext_font_data_destroy (data);
142    data = (hb_coretext_font_data_t *) hb_font_get_user_data (font, &hb_coretext_data_key);
143    if (data)
144      return data;
145    else
146      return &_hb_coretext_font_data_nil;
147  }
148
149  return data;
150}
151
152CTFontRef
153hb_coretext_font_get_ct_font (hb_font_t *font)
154{
155  hb_coretext_font_data_t *font_data = _hb_coretext_font_get_data (font);
156  if (unlikely (!font_data))
157    return 0;
158  return font_data->ct_font;
159}
160
161
162hb_bool_t
163_hb_coretext_shape (hb_font_t          *font,
164                    hb_buffer_t        *buffer,
165                    const hb_feature_t *features,
166                    unsigned int        num_features)
167{
168  buffer->guess_properties ();
169
170#define FAIL(...) \
171  HB_STMT_START { \
172    DEBUG_MSG (CORETEXT, NULL, __VA_ARGS__); \
173    return false; \
174  } HB_STMT_END;
175
176  hb_coretext_face_data_t *face_data = _hb_coretext_face_get_data (font->face);
177  if (unlikely (!face_data->cg_font))
178    FAIL ("Couldn't get face data");
179
180  hb_coretext_font_data_t *font_data = _hb_coretext_font_get_data (font);
181  if (unlikely (!font_data->ct_font))
182    FAIL ("Couldn't get font font");
183
184  if (unlikely (!buffer->len))
185    return true;
186
187  unsigned int scratch_size;
188  char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
189
190#define utf16_index() var1.u32
191
192  UniChar *pchars = (UniChar *) scratch;
193  unsigned int chars_len = 0;
194  for (unsigned int i = 0; i < buffer->len; i++) {
195    hb_codepoint_t c = buffer->info[i].codepoint;
196    buffer->info[i].utf16_index() = chars_len;
197    if (likely (c < 0x10000))
198      pchars[chars_len++] = c;
199    else if (unlikely (c >= 0x110000))
200      pchars[chars_len++] = 0xFFFD;
201    else {
202      pchars[chars_len++] = 0xD800 + ((c - 0x10000) >> 10);
203      pchars[chars_len++] = 0xDC00 + ((c - 0x10000) & ((1 << 10) - 1));
204    }
205  }
206
207#undef utf16_index
208
209  CFStringRef string_ref = CFStringCreateWithCharactersNoCopy (kCFAllocatorDefault,
210                                                               pchars, chars_len,
211                                                               kCFAllocatorNull);
212
213  CFDictionaryRef attrs = CFDictionaryCreate (kCFAllocatorDefault,
214                                              (const void**) &kCTFontAttributeName,
215                                              (const void**) &font_data->ct_font,
216                                              1, // count of attributes
217                                              &kCFTypeDictionaryKeyCallBacks,
218                                              &kCFTypeDictionaryValueCallBacks);
219
220  // TODO: support features
221
222  // Now we can create an attributed string
223  CFAttributedStringRef attr_string = CFAttributedStringCreate (kCFAllocatorDefault, string_ref, attrs);
224  CFRelease (string_ref);
225  CFRelease (attrs);
226
227  // Create the CoreText line from our string, then we're done with it
228  CTLineRef line = CTLineCreateWithAttributedString (attr_string);
229  CFRelease (attr_string);
230
231  // and finally retrieve the glyph data and store into the gfxTextRun
232  CFArrayRef glyph_runs = CTLineGetGlyphRuns (line);
233  unsigned int num_runs = CFArrayGetCount (glyph_runs);
234
235  // Iterate through the glyph runs.
236  bool success = true;
237  buffer->len = 0;
238
239  const CFRange range_all = CFRangeMake (0, 0);
240
241  for (unsigned int i = 0; i < num_runs; i++) {
242    CTRunRef run = (CTRunRef) CFArrayGetValueAtIndex (glyph_runs, i);
243
244    unsigned int num_glyphs = CTRunGetGlyphCount (run);
245    if (num_glyphs == 0)
246      continue;
247
248    buffer->ensure (buffer->len + num_glyphs);
249
250    // retrieve the laid-out glyph data from the CTRun
251
252    // Testing indicates that CTRunGetGlyphsPtr (almost?) always succeeds,
253    // and so copying data to our own buffer with CTRunGetGlyphs will be
254    // extremely rare.
255
256    unsigned int scratch_size;
257    char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
258
259#define ALLOCATE_ARRAY(Type, name, len) \
260  Type *name = (Type *) scratch; \
261  scratch += (len) * sizeof ((name)[0]); \
262  scratch_size -= (len) * sizeof ((name)[0]);
263
264    const CGGlyph* glyphs = CTRunGetGlyphsPtr (run);
265    if (!glyphs) {
266      ALLOCATE_ARRAY (CGGlyph, glyph_buf, num_glyphs);
267      CTRunGetGlyphs (run, range_all, glyph_buf);
268      glyphs = glyph_buf;
269    }
270
271    const CGPoint* positions = CTRunGetPositionsPtr (run);
272    if (!positions) {
273      ALLOCATE_ARRAY (CGPoint, position_buf, num_glyphs);
274      CTRunGetPositions (run, range_all, position_buf);
275      positions = position_buf;
276    }
277
278    const CFIndex* string_indices = CTRunGetStringIndicesPtr (run);
279    if (!string_indices) {
280      ALLOCATE_ARRAY (CFIndex, index_buf, num_glyphs);
281      CTRunGetStringIndices (run, range_all, index_buf);
282      string_indices = index_buf;
283    }
284
285#undef ALLOCATE_ARRAY
286
287    double run_width = CTRunGetTypographicBounds (run, range_all, NULL, NULL, NULL);
288
289    for (unsigned int j = 0; j < num_glyphs; j++) {
290      double advance = (j + 1 < num_glyphs ? positions[j + 1].x : positions[0].x + run_width) - positions[j].x;
291
292      hb_glyph_info_t *info = &buffer->info[buffer->len];
293      hb_glyph_position_t *pos = &buffer->pos[buffer->len];
294
295      info->codepoint = glyphs[j];
296      info->cluster = string_indices[j];
297
298      // currently, we do all x-positioning by setting the advance, we never use x-offset
299      info->mask = advance;
300      info->var1.u32 = 0;
301      info->var2.u32 = positions[j].y;
302
303      buffer->len++;
304    }
305  }
306
307  buffer->clear_positions ();
308
309  unsigned int count = buffer->len;
310  for (unsigned int i = 0; i < count; ++i) {
311    hb_glyph_info_t *info = &buffer->info[i];
312    hb_glyph_position_t *pos = &buffer->pos[i];
313
314    /* TODO vertical */
315    pos->x_advance = info->mask;
316    pos->x_offset = info->var1.u32;
317    pos->y_offset = info->var2.u32;
318  }
319
320  // Fix up clusters so that we never return out-of-order indices;
321  // if core text has reordered glyphs, we'll merge them to the
322  // beginning of the reordered cluster.
323  // This does *not* mean we'll form the same clusters as Uniscribe
324  // or the native OT backend, only that the cluster indices will be
325  // non-decreasing in the output buffer.
326  if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
327    unsigned int prev_cluster = 0;
328    for (unsigned int i = 0; i < count; i++) {
329      unsigned int curr_cluster = buffer->info[i].cluster;
330      if (curr_cluster < prev_cluster) {
331        for (unsigned int j = i; j > 0; j--) {
332          if (buffer->info[j - 1].cluster > curr_cluster)
333            buffer->info[j - 1].cluster = curr_cluster;
334          else
335            break;
336        }
337      }
338      prev_cluster = curr_cluster;
339    }
340  } else {
341    // For RTL runs, we make them non-increasing instead.
342    unsigned int prev_cluster = (unsigned int)-1;
343    for (unsigned int i = 0; i < count; i++) {
344      unsigned int curr_cluster = buffer->info[i].cluster;
345      if (curr_cluster > prev_cluster) {
346        for (unsigned int j = i; j > 0; j--) {
347          if (buffer->info[j - 1].cluster < curr_cluster)
348            buffer->info[j - 1].cluster = curr_cluster;
349          else
350            break;
351        }
352      }
353      prev_cluster = curr_cluster;
354    }
355  }
356
357  return true;
358}
359