hb-ft.cc revision 5821806d5e7f356e8fa4b058a389a808ea183019
1/* 2 * Copyright © 2009 Red Hat, Inc. 3 * Copyright © 2009 Keith Stribley 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 * Red Hat Author(s): Behdad Esfahbod 26 */ 27 28#include "hb-private.hh" 29 30#include "hb-ft.h" 31 32#include "hb-font-private.hh" 33 34#include FT_ADVANCES_H 35#include FT_TRUETYPE_TABLES_H 36 37 38 39#ifndef HB_DEBUG_FT 40#define HB_DEBUG_FT (HB_DEBUG+0) 41#endif 42 43 44/* TODO: 45 * 46 * In general, this file does a fine job of what it's supposed to do. 47 * There are, however, things that need more work: 48 * 49 * - We don't handle any load_flags. That definitely has API implications. :( 50 * I believe hb_ft_font_create() should take load_flags input. 51 * In particular, FT_Get_Advance() without the NO_HINTING flag seems to be 52 * buggy. 53 * 54 * - We don't handle / allow for emboldening / obliqueing. 55 * 56 * - Rounding, etc? 57 * 58 * - In the future, we should add constructors to create fonts in font space. 59 * 60 * - I believe transforms are not correctly implemented. FreeType does not 61 * provide any API to get to the transform/delta set on the face. :( 62 * 63 * - Always use FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH? 64 * 65 * - FT_Load_Glyph() is exteremely costly. Do something about it? 66 */ 67 68 69static hb_bool_t 70hb_ft_get_glyph (hb_font_t *font HB_UNUSED, 71 void *font_data, 72 hb_codepoint_t unicode, 73 hb_codepoint_t variation_selector, 74 hb_codepoint_t *glyph, 75 void *user_data HB_UNUSED) 76 77{ 78 FT_Face ft_face = (FT_Face) font_data; 79 80#ifdef HAVE_FT_FACE_GETCHARVARIANTINDEX 81 if (unlikely (variation_selector)) { 82 *glyph = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector); 83 if (*glyph) 84 return true; 85 } 86#endif 87 88 *glyph = FT_Get_Char_Index (ft_face, unicode); 89 return *glyph != 0; 90} 91 92static hb_position_t 93hb_ft_get_glyph_h_advance (hb_font_t *font HB_UNUSED, 94 void *font_data, 95 hb_codepoint_t glyph, 96 void *user_data HB_UNUSED) 97{ 98 FT_Face ft_face = (FT_Face) font_data; 99 int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING; 100 FT_Fixed v; 101 102 if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v))) 103 return 0; 104 105 return v >> 10; 106} 107 108static hb_position_t 109hb_ft_get_glyph_v_advance (hb_font_t *font HB_UNUSED, 110 void *font_data, 111 hb_codepoint_t glyph, 112 void *user_data HB_UNUSED) 113{ 114 FT_Face ft_face = (FT_Face) font_data; 115 int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING | FT_LOAD_VERTICAL_LAYOUT; 116 FT_Fixed v; 117 118 if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v))) 119 return 0; 120 121 /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates 122 * have a Y growing upward. Hence the extra negation. */ 123 return -v >> 10; 124} 125 126static hb_bool_t 127hb_ft_get_glyph_h_origin (hb_font_t *font HB_UNUSED, 128 void *font_data HB_UNUSED, 129 hb_codepoint_t glyph HB_UNUSED, 130 hb_position_t *x HB_UNUSED, 131 hb_position_t *y HB_UNUSED, 132 void *user_data HB_UNUSED) 133{ 134 /* We always work in the horizontal coordinates. */ 135 return true; 136} 137 138static hb_bool_t 139hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED, 140 void *font_data, 141 hb_codepoint_t glyph, 142 hb_position_t *x, 143 hb_position_t *y, 144 void *user_data HB_UNUSED) 145{ 146 FT_Face ft_face = (FT_Face) font_data; 147 int load_flags = FT_LOAD_DEFAULT; 148 149 if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags))) 150 return false; 151 152 /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates 153 * have a Y growing upward. Hence the extra negation. */ 154 *x = ft_face->glyph->metrics.horiBearingX - ft_face->glyph->metrics.vertBearingX; 155 *y = ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY); 156 157 return true; 158} 159 160static hb_position_t 161hb_ft_get_glyph_h_kerning (hb_font_t *font, 162 void *font_data, 163 hb_codepoint_t left_glyph, 164 hb_codepoint_t right_glyph, 165 void *user_data HB_UNUSED) 166{ 167 FT_Face ft_face = (FT_Face) font_data; 168 FT_Vector kerningv; 169 170 FT_Kerning_Mode mode = font->x_ppem ? FT_KERNING_DEFAULT : FT_KERNING_UNFITTED; 171 if (FT_Get_Kerning (ft_face, left_glyph, right_glyph, mode, &kerningv)) 172 return 0; 173 174 return kerningv.x; 175} 176 177static hb_position_t 178hb_ft_get_glyph_v_kerning (hb_font_t *font HB_UNUSED, 179 void *font_data HB_UNUSED, 180 hb_codepoint_t top_glyph HB_UNUSED, 181 hb_codepoint_t bottom_glyph HB_UNUSED, 182 void *user_data HB_UNUSED) 183{ 184 /* FreeType API doesn't support vertical kerning */ 185 return 0; 186} 187 188static hb_bool_t 189hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED, 190 void *font_data, 191 hb_codepoint_t glyph, 192 hb_glyph_extents_t *extents, 193 void *user_data HB_UNUSED) 194{ 195 FT_Face ft_face = (FT_Face) font_data; 196 int load_flags = FT_LOAD_DEFAULT; 197 198 if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags))) 199 return false; 200 201 extents->x_bearing = ft_face->glyph->metrics.horiBearingX; 202 extents->y_bearing = ft_face->glyph->metrics.horiBearingY; 203 extents->width = ft_face->glyph->metrics.width; 204 extents->height = -ft_face->glyph->metrics.height; 205 return true; 206} 207 208static hb_bool_t 209hb_ft_get_glyph_contour_point (hb_font_t *font HB_UNUSED, 210 void *font_data, 211 hb_codepoint_t glyph, 212 unsigned int point_index, 213 hb_position_t *x, 214 hb_position_t *y, 215 void *user_data HB_UNUSED) 216{ 217 FT_Face ft_face = (FT_Face) font_data; 218 int load_flags = FT_LOAD_DEFAULT; 219 220 if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags))) 221 return false; 222 223 if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE)) 224 return false; 225 226 if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points)) 227 return false; 228 229 *x = ft_face->glyph->outline.points[point_index].x; 230 *y = ft_face->glyph->outline.points[point_index].y; 231 232 return true; 233} 234 235static hb_bool_t 236hb_ft_get_glyph_name (hb_font_t *font HB_UNUSED, 237 void *font_data, 238 hb_codepoint_t glyph, 239 char *name, unsigned int size, 240 void *user_data HB_UNUSED) 241{ 242 FT_Face ft_face = (FT_Face) font_data; 243 244 hb_bool_t ret = !FT_Get_Glyph_Name (ft_face, glyph, name, size); 245 if (!ret) 246 snprintf (name, size, "gid%u", glyph); 247 248 return ret; 249} 250 251static hb_bool_t 252hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED, 253 void *font_data, 254 const char *name, int len, /* -1 means nul-terminated */ 255 hb_codepoint_t *glyph, 256 void *user_data HB_UNUSED) 257{ 258 FT_Face ft_face = (FT_Face) font_data; 259 260 if (len < 0) 261 *glyph = FT_Get_Name_Index (ft_face, (FT_String *) name); 262 else { 263 /* Make a nul-terminated version. */ 264 char buf[128]; 265 len = MIN (len, (int) sizeof (buf) - 1); 266 strncpy (buf, name, len); 267 buf[len] = '\0'; 268 *glyph = FT_Get_Name_Index (ft_face, buf); 269 } 270 271 return *glyph != 0; 272} 273 274 275static hb_font_funcs_t * 276_hb_ft_get_font_funcs (void) 277{ 278 static const hb_font_funcs_t ft_ffuncs = { 279 HB_OBJECT_HEADER_STATIC, 280 281 true, /* immutable */ 282 283 { 284#define HB_FONT_FUNC_IMPLEMENT(name) hb_ft_get_##name, 285 HB_FONT_FUNCS_IMPLEMENT_CALLBACKS 286#undef HB_FONT_FUNC_IMPLEMENT 287 } 288 }; 289 290 return const_cast<hb_font_funcs_t *> (&ft_ffuncs); 291} 292 293 294static hb_blob_t * 295reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data) 296{ 297 FT_Face ft_face = (FT_Face) user_data; 298 FT_Byte *buffer; 299 FT_ULong length = 0; 300 FT_Error error; 301 302 /* Note: FreeType like HarfBuzz uses the NONE tag for fetching the entire blob */ 303 304 error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length); 305 if (error) 306 return NULL; 307 308 buffer = (FT_Byte *) malloc (length); 309 if (buffer == NULL) 310 return NULL; 311 312 error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length); 313 if (error) 314 return NULL; 315 316 return hb_blob_create ((const char *) buffer, length, 317 HB_MEMORY_MODE_WRITABLE, 318 buffer, free); 319} 320 321 322hb_face_t * 323hb_ft_face_create (FT_Face ft_face, 324 hb_destroy_func_t destroy) 325{ 326 hb_face_t *face; 327 328 if (ft_face->stream->read == NULL) { 329 hb_blob_t *blob; 330 331 blob = hb_blob_create ((const char *) ft_face->stream->base, 332 (unsigned int) ft_face->stream->size, 333 /* TODO: We assume that it's mmap()'ed, but FreeType code 334 * suggests that there are cases we reach here but font is 335 * not mmapped. For example, when mmap() fails. No idea 336 * how to deal with it better here. */ 337 HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE, 338 ft_face, destroy); 339 face = hb_face_create (blob, ft_face->face_index); 340 hb_blob_destroy (blob); 341 } else { 342 face = hb_face_create_for_tables (reference_table, ft_face, destroy); 343 } 344 345 hb_face_set_index (face, ft_face->face_index); 346 hb_face_set_upem (face, ft_face->units_per_EM); 347 348 return face; 349} 350 351static void 352hb_ft_face_finalize (FT_Face ft_face) 353{ 354 hb_face_destroy ((hb_face_t *) ft_face->generic.data); 355} 356 357hb_face_t * 358hb_ft_face_create_cached (FT_Face ft_face) 359{ 360 if (unlikely (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer) hb_ft_face_finalize)) 361 { 362 if (ft_face->generic.finalizer) 363 ft_face->generic.finalizer (ft_face); 364 365 ft_face->generic.data = hb_ft_face_create (ft_face, NULL); 366 ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize; 367 } 368 369 return hb_face_reference ((hb_face_t *) ft_face->generic.data); 370} 371 372static void 373_do_nothing (void) 374{ 375} 376 377 378hb_font_t * 379hb_ft_font_create (FT_Face ft_face, 380 hb_destroy_func_t destroy) 381{ 382 hb_font_t *font; 383 hb_face_t *face; 384 385 face = hb_ft_face_create (ft_face, destroy); 386 font = hb_font_create (face); 387 hb_face_destroy (face); 388 hb_font_set_funcs (font, 389 _hb_ft_get_font_funcs (), 390 ft_face, (hb_destroy_func_t) _do_nothing); 391 hb_font_set_scale (font, 392 ((uint64_t) ft_face->size->metrics.x_scale * (uint64_t) ft_face->units_per_EM) >> 16, 393 ((uint64_t) ft_face->size->metrics.y_scale * (uint64_t) ft_face->units_per_EM) >> 16); 394 hb_font_set_ppem (font, 395 ft_face->size->metrics.x_ppem, 396 ft_face->size->metrics.y_ppem); 397 398 return font; 399} 400 401 402/* Thread-safe, lock-free, FT_Library */ 403 404static FT_Library ft_library; 405 406static 407void free_ft_library (void) 408{ 409 FT_Done_FreeType (ft_library); 410} 411 412static FT_Library 413get_ft_library (void) 414{ 415retry: 416 FT_Library library = (FT_Library) hb_atomic_ptr_get (&ft_library); 417 418 if (unlikely (!library)) 419 { 420 /* Not found; allocate one. */ 421 if (FT_Init_FreeType (&library)) 422 return NULL; 423 424 if (!hb_atomic_ptr_cmpexch (&ft_library, NULL, library)) { 425 FT_Done_FreeType (library); 426 goto retry; 427 } 428 429#ifdef HAVE_ATEXIT 430 atexit (free_ft_library); /* First person registers atexit() callback. */ 431#endif 432 } 433 434 return library; 435} 436 437static void 438_release_blob (FT_Face ft_face) 439{ 440 hb_blob_destroy ((hb_blob_t *) ft_face->generic.data); 441} 442 443void 444hb_ft_font_set_funcs (hb_font_t *font) 445{ 446 hb_blob_t *blob = hb_face_reference_blob (font->face); 447 unsigned int blob_length; 448 const char *blob_data = hb_blob_get_data (blob, &blob_length); 449 if (unlikely (!blob_length)) 450 DEBUG_MSG (FT, font, "Font face has empty blob"); 451 452 FT_Face ft_face = NULL; 453 FT_Error err = FT_New_Memory_Face (get_ft_library (), 454 (const FT_Byte *) blob_data, 455 blob_length, 456 hb_face_get_index (font->face), 457 &ft_face); 458 459 if (unlikely (err)) { 460 hb_blob_destroy (blob); 461 DEBUG_MSG (FT, font, "Font face FT_New_Memory_Face() failed"); 462 return; 463 } 464 465 FT_Select_Charmap (ft_face, FT_ENCODING_UNICODE); 466 467 assert (font->y_scale >= 0); 468 FT_Set_Char_Size (ft_face, 469 font->x_scale, font->y_scale, 470 0, 0); 471#if 0 472 font->x_ppem * 72 * 64 / font->x_scale, 473 font->y_ppem * 72 * 64 / font->y_scale); 474#endif 475 476 ft_face->generic.data = blob; 477 ft_face->generic.finalizer = (FT_Generic_Finalizer) _release_blob; 478 479 hb_font_set_funcs (font, 480 _hb_ft_get_font_funcs (), 481 ft_face, 482 (hb_destroy_func_t) FT_Done_Face); 483} 484 485FT_Face 486hb_ft_font_get_face (hb_font_t *font) 487{ 488 if (font->destroy == (hb_destroy_func_t) FT_Done_Face || 489 font->destroy == (hb_destroy_func_t) _do_nothing) 490 return (FT_Face) font->user_data; 491 492 return NULL; 493} 494