hb-coretext.cc revision 7d52e6601f0e695690cd168a288466746cf25300 
1/*
2 * Copyright © 2012  Mozilla Foundation.
3 * Copyright © 2012  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 * Mozilla Author(s): Jonathan Kew
26 * Google Author(s): Behdad Esfahbod
27 */
28
29#define HB_SHAPER coretext
30#include "hb-shaper-impl-private.hh"
31
32#define GlyphID GlyphID_mac
33#include <ApplicationServices/ApplicationServices.h>
34#undef GlyphID
35
36#include "hb-coretext.h"
37
38
39#ifndef HB_DEBUG_CORETEXT
40#define HB_DEBUG_CORETEXT (HB_DEBUG+0)
41#endif
42
43
44HB_SHAPER_DATA_ENSURE_DECLARE(coretext, face)
45HB_SHAPER_DATA_ENSURE_DECLARE(coretext, font)
46
47
48/*
49 * shaper face data
50 */
51
52struct hb_coretext_shaper_face_data_t {
53  CGFontRef cg_font;
54};
55
56static void
57release_data (void *info, const void *data, size_t size)
58{
59  assert (hb_blob_get_length ((hb_blob_t *) info) == size &&
60          hb_blob_get_data ((hb_blob_t *) info, NULL) == data);
61
62  hb_blob_destroy ((hb_blob_t *) info);
63}
64
65hb_coretext_shaper_face_data_t *
66_hb_coretext_shaper_face_data_create (hb_face_t *face)
67{
68  hb_coretext_shaper_face_data_t *data = (hb_coretext_shaper_face_data_t *) calloc (1, sizeof (hb_coretext_shaper_face_data_t));
69  if (unlikely (!data))
70    return NULL;
71
72  hb_blob_t *blob = hb_face_reference_blob (face);
73  unsigned int blob_length;
74  const char *blob_data = hb_blob_get_data (blob, &blob_length);
75  if (unlikely (!blob_length))
76    DEBUG_MSG (CORETEXT, face, "Face has empty blob");
77
78  CGDataProviderRef provider = CGDataProviderCreateWithData (blob, blob_data, blob_length, &release_data);
79  data->cg_font = CGFontCreateWithDataProvider (provider);
80  CGDataProviderRelease (provider);
81
82  if (unlikely (!data->cg_font)) {
83    DEBUG_MSG (CORETEXT, face, "Face CGFontCreateWithDataProvider() failed");
84    free (data);
85    return NULL;
86  }
87
88  return data;
89}
90
91void
92_hb_coretext_shaper_face_data_destroy (hb_coretext_shaper_face_data_t *data)
93{
94  CFRelease (data->cg_font);
95  free (data);
96}
97
98
99/*
100 * shaper font data
101 */
102
103struct hb_coretext_shaper_font_data_t {
104  CTFontRef ct_font;
105};
106
107hb_coretext_shaper_font_data_t *
108_hb_coretext_shaper_font_data_create (hb_font_t *font)
109{
110  if (unlikely (!hb_coretext_shaper_face_data_ensure (font->face))) return NULL;
111
112  hb_coretext_shaper_font_data_t *data = (hb_coretext_shaper_font_data_t *) calloc (1, sizeof (hb_coretext_shaper_font_data_t));
113  if (unlikely (!data))
114    return NULL;
115
116  hb_face_t *face = font->face;
117  hb_coretext_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
118
119  data->ct_font = CTFontCreateWithGraphicsFont (face_data->cg_font, font->y_scale, NULL, NULL);
120  if (unlikely (!data->ct_font)) {
121    DEBUG_MSG (CORETEXT, font, "Font CTFontCreateWithGraphicsFont() failed");
122    free (data);
123    return NULL;
124  }
125
126  return data;
127}
128
129void
130_hb_coretext_shaper_font_data_destroy (hb_coretext_shaper_font_data_t *data)
131{
132  CFRelease (data->ct_font);
133  free (data);
134}
135
136
137/*
138 * shaper shape_plan data
139 */
140
141struct hb_coretext_shaper_shape_plan_data_t {};
142
143hb_coretext_shaper_shape_plan_data_t *
144_hb_coretext_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
145					     const hb_feature_t *user_features HB_UNUSED,
146					     unsigned int        num_user_features HB_UNUSED)
147{
148  return (hb_coretext_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
149}
150
151void
152_hb_coretext_shaper_shape_plan_data_destroy (hb_coretext_shaper_shape_plan_data_t *data HB_UNUSED)
153{
154}
155
156
157/*
158 * shaper
159 */
160
161CTFontRef
162hb_coretext_font_get_ct_font (hb_font_t *font)
163{
164  if (unlikely (!hb_coretext_shaper_font_data_ensure (font))) return 0;
165  hb_coretext_shaper_font_data_t *font_data = HB_SHAPER_DATA_GET (font);
166  return font_data->ct_font;
167}
168
169hb_bool_t
170_hb_coretext_shape (hb_shape_plan_t    *shape_plan,
171		    hb_font_t          *font,
172                    hb_buffer_t        *buffer,
173                    const hb_feature_t *features,
174                    unsigned int        num_features)
175{
176  hb_face_t *face = font->face;
177  hb_coretext_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
178  hb_coretext_shaper_font_data_t *font_data = HB_SHAPER_DATA_GET (font);
179
180#define FAIL(...) \
181  HB_STMT_START { \
182    DEBUG_MSG (CORETEXT, NULL, __VA_ARGS__); \
183    return false; \
184  } HB_STMT_END;
185
186  unsigned int scratch_size;
187  char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
188
189#define utf16_index() var1.u32
190
191  UniChar *pchars = (UniChar *) scratch;
192  unsigned int chars_len = 0;
193  for (unsigned int i = 0; i < buffer->len; i++) {
194    hb_codepoint_t c = buffer->info[i].codepoint;
195    buffer->info[i].utf16_index() = chars_len;
196    if (likely (c < 0x10000))
197      pchars[chars_len++] = c;
198    else if (unlikely (c >= 0x110000))
199      pchars[chars_len++] = 0xFFFD;
200    else {
201      pchars[chars_len++] = 0xD800 + ((c - 0x10000) >> 10);
202      pchars[chars_len++] = 0xDC00 + ((c - 0x10000) & ((1 << 10) - 1));
203    }
204  }
205
206#undef utf16_index
207
208  CFStringRef string_ref = CFStringCreateWithCharactersNoCopy (kCFAllocatorDefault,
209                                                               pchars, chars_len,
210                                                               kCFAllocatorNull);
211
212  CFDictionaryRef attrs = CFDictionaryCreate (kCFAllocatorDefault,
213                                              (const void**) &kCTFontAttributeName,
214                                              (const void**) &font_data->ct_font,
215                                              1, /* count of attributes */
216                                              &kCFTypeDictionaryKeyCallBacks,
217                                              &kCFTypeDictionaryValueCallBacks);
218
219  /* TODO: support features */
220
221  CFAttributedStringRef attr_string = CFAttributedStringCreate (kCFAllocatorDefault, string_ref, attrs);
222  CFRelease (string_ref);
223  CFRelease (attrs);
224
225  CTLineRef line = CTLineCreateWithAttributedString (attr_string);
226  CFRelease (attr_string);
227
228  CFArrayRef glyph_runs = CTLineGetGlyphRuns (line);
229  unsigned int num_runs = CFArrayGetCount (glyph_runs);
230
231  bool success = true;
232  buffer->len = 0;
233
234  const CFRange range_all = CFRangeMake (0, 0);
235
236  for (unsigned int i = 0; i < num_runs; i++) {
237    CTRunRef run = (CTRunRef) CFArrayGetValueAtIndex (glyph_runs, i);
238
239    unsigned int num_glyphs = CTRunGetGlyphCount (run);
240    if (num_glyphs == 0)
241      continue;
242
243    buffer->ensure (buffer->len + num_glyphs);
244
245    /* Testing indicates that CTRunGetGlyphsPtr (almost?) always succeeds,
246     * and so copying data to our own buffer with CTRunGetGlyphs will be
247     * extremely rare. */
248
249    unsigned int scratch_size;
250    char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
251
252#define ALLOCATE_ARRAY(Type, name, len) \
253  Type *name = (Type *) scratch; \
254  scratch += (len) * sizeof ((name)[0]); \
255  scratch_size -= (len) * sizeof ((name)[0]);
256
257    const CGGlyph* glyphs = CTRunGetGlyphsPtr (run);
258    if (!glyphs) {
259      ALLOCATE_ARRAY (CGGlyph, glyph_buf, num_glyphs);
260      CTRunGetGlyphs (run, range_all, glyph_buf);
261      glyphs = glyph_buf;
262    }
263
264    const CGPoint* positions = CTRunGetPositionsPtr (run);
265    if (!positions) {
266      ALLOCATE_ARRAY (CGPoint, position_buf, num_glyphs);
267      CTRunGetPositions (run, range_all, position_buf);
268      positions = position_buf;
269    }
270
271    const CFIndex* string_indices = CTRunGetStringIndicesPtr (run);
272    if (!string_indices) {
273      ALLOCATE_ARRAY (CFIndex, index_buf, num_glyphs);
274      CTRunGetStringIndices (run, range_all, index_buf);
275      string_indices = index_buf;
276    }
277
278#undef ALLOCATE_ARRAY
279
280    double run_width = CTRunGetTypographicBounds (run, range_all, NULL, NULL, NULL);
281
282    for (unsigned int j = 0; j < num_glyphs; j++) {
283      double advance = (j + 1 < num_glyphs ? positions[j + 1].x : positions[0].x + run_width) - positions[j].x;
284
285      hb_glyph_info_t *info = &buffer->info[buffer->len];
286      hb_glyph_position_t *pos = &buffer->pos[buffer->len];
287
288      info->codepoint = glyphs[j];
289      info->cluster = string_indices[j];
290
291      /* Currently, we do all x-positioning by setting the advance, we never use x-offset. */
292      info->mask = advance;
293      info->var1.u32 = 0;
294      info->var2.u32 = positions[j].y;
295
296      buffer->len++;
297    }
298  }
299
300  buffer->clear_positions ();
301
302  unsigned int count = buffer->len;
303  for (unsigned int i = 0; i < count; ++i) {
304    hb_glyph_info_t *info = &buffer->info[i];
305    hb_glyph_position_t *pos = &buffer->pos[i];
306
307    /* TODO vertical */
308    pos->x_advance = info->mask;
309    pos->x_offset = info->var1.u32;
310    pos->y_offset = info->var2.u32;
311  }
312
313  /* Fix up clusters so that we never return out-of-order indices;
314   * if core text has reordered glyphs, we'll merge them to the
315   * beginning of the reordered cluster.
316   *
317   * This does *not* mean we'll form the same clusters as Uniscribe
318   * or the native OT backend, only that the cluster indices will be
319   * monotonic in the output buffer. */
320  if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
321    unsigned int prev_cluster = 0;
322    for (unsigned int i = 0; i < count; i++) {
323      unsigned int curr_cluster = buffer->info[i].cluster;
324      if (curr_cluster < prev_cluster) {
325        for (unsigned int j = i; j > 0; j--) {
326          if (buffer->info[j - 1].cluster > curr_cluster)
327            buffer->info[j - 1].cluster = curr_cluster;
328          else
329            break;
330        }
331      }
332      prev_cluster = curr_cluster;
333    }
334  } else {
335    unsigned int prev_cluster = (unsigned int)-1;
336    for (unsigned int i = 0; i < count; i++) {
337      unsigned int curr_cluster = buffer->info[i].cluster;
338      if (curr_cluster > prev_cluster) {
339        for (unsigned int j = i; j > 0; j--) {
340          if (buffer->info[j - 1].cluster < curr_cluster)
341            buffer->info[j - 1].cluster = curr_cluster;
342          else
343            break;
344        }
345      }
346      prev_cluster = curr_cluster;
347    }
348  }
349
350  return true;
351}
352