2 * Copyright (C) 2006 Evgeniy Stepanov <eugeni.stepanov@gmail.com>
4 * This file is part of libass.
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23 #include FT_FREETYPE_H
24 #include FT_SYNTHESIS_H
26 #include FT_TRUETYPE_TABLES_H
31 #include "ass_library.h"
33 #include "ass_fontconfig.h"
34 #include "ass_utils.h"
36 #define VERTICAL_LOWER_BOUND 0x02f1
39 * Select a good charmap, prefer Microsoft Unicode charmaps.
40 * Otherwise, let FreeType decide.
42 static void charmap_magic(ASS_Library *library, FT_Face face)
47 // Search for a Microsoft Unicode cmap
48 for (i = 0; i < face->num_charmaps; ++i) {
49 FT_CharMap cmap = face->charmaps[i];
50 unsigned pid = cmap->platform_id;
51 unsigned eid = cmap->encoding_id;
52 if (pid == 3 /*microsoft */
53 && (eid == 1 /*unicode bmp */
54 || eid == 10 /*full unicode */ )) {
55 FT_Set_Charmap(face, cmap);
57 } else if (pid == 3 && ms_cmap < 0)
61 // Try the first Microsoft cmap if no Microsoft Unicode cmap was found
63 FT_CharMap cmap = face->charmaps[ms_cmap];
64 FT_Set_Charmap(face, cmap);
69 if (face->num_charmaps == 0) {
70 ass_msg(library, MSGL_WARN, "Font face with no charmaps");
73 ass_msg(library, MSGL_WARN,
74 "No charmap autodetected, trying the first one");
75 FT_Set_Charmap(face, face->charmaps[0]);
81 * \brief find a memory font by name
83 static int find_font(ASS_Library *library, char *name)
86 for (i = 0; i < library->num_fontdata; ++i)
87 if (strcasecmp(name, library->fontdata[i].name) == 0)
92 static void face_set_size(FT_Face face, double size);
94 static void buggy_font_workaround(FT_Face face)
96 // Some fonts have zero Ascender/Descender fields in 'hhea' table.
97 // In this case, get the information from 'os2' table or, as
98 // a last resort, from face.bbox.
99 if (face->ascender + face->descender == 0 || face->height == 0) {
100 TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2);
102 face->ascender = os2->sTypoAscender;
103 face->descender = os2->sTypoDescender;
104 face->height = face->ascender - face->descender;
106 face->ascender = face->bbox.yMax;
107 face->descender = face->bbox.yMin;
108 face->height = face->ascender - face->descender;
114 * \brief Select a face with the given charcode and add it to ASS_Font
115 * \return index of the new face in font->faces, -1 if failed
117 static int add_face(void *fc_priv, ASS_Font *font, uint32_t ch)
125 if (font->n_faces == ASS_FONT_MAX_FACES)
129 fontconfig_select(font->library, fc_priv, font->desc.family,
130 font->desc.treat_family_as_pattern,
131 font->desc.bold, font->desc.italic, &index, ch);
135 mem_idx = find_font(font->library, path);
138 FT_New_Memory_Face(font->ftlibrary,
139 (unsigned char *) font->library->
140 fontdata[mem_idx].data,
141 font->library->fontdata[mem_idx].size, index,
144 ass_msg(font->library, MSGL_WARN,
145 "Error opening memory font: '%s'", path);
150 error = FT_New_Face(font->ftlibrary, path, index, &face);
152 ass_msg(font->library, MSGL_WARN,
153 "Error opening font: '%s', %d", path, index);
158 charmap_magic(font->library, face);
159 buggy_font_workaround(face);
161 font->faces[font->n_faces++] = face;
162 face_set_size(face, font->size);
164 return font->n_faces - 1;
168 * \brief Create a new ASS_Font according to "desc" argument
170 ASS_Font *ass_font_new(Cache *font_cache, ASS_Library *library,
171 FT_Library ftlibrary, void *fc_priv,
178 fontp = ass_cache_get(font_cache, desc);
182 font.library = library;
183 font.ftlibrary = ftlibrary;
185 font.desc.family = strdup(desc->family);
186 font.desc.treat_family_as_pattern = desc->treat_family_as_pattern;
187 font.desc.bold = desc->bold;
188 font.desc.italic = desc->italic;
189 font.desc.vertical = desc->vertical;
191 font.scale_x = font.scale_y = 1.;
192 font.v.x = font.v.y = 0;
195 error = add_face(fc_priv, &font, 0);
197 free(font.desc.family);
200 return ass_cache_put(font_cache, &font.desc, &font);
204 * \brief Set font transformation matrix and shift vector
206 void ass_font_set_transform(ASS_Font *font, double scale_x,
207 double scale_y, FT_Vector *v)
209 font->scale_x = scale_x;
210 font->scale_y = scale_y;
217 static void face_set_size(FT_Face face, double size)
219 TT_HoriHeader *hori = FT_Get_Sfnt_Table(face, ft_sfnt_hhea);
220 TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2);
222 FT_Size_RequestRec rq;
223 FT_Size_Metrics *m = &face->size->metrics;
224 // VSFilter uses metrics from TrueType OS/2 table
225 // The idea was borrowed from asa (http://asa.diac24.net)
227 int hori_height = hori->Ascender - hori->Descender;
228 int os2_height = os2->usWinAscent + os2->usWinDescent;
229 if (hori_height && os2_height)
230 mscale = (double) hori_height / os2_height;
232 memset(&rq, 0, sizeof(rq));
233 rq.type = FT_SIZE_REQUEST_TYPE_REAL_DIM;
235 rq.height = double_to_d6(size * mscale);
236 rq.horiResolution = rq.vertResolution = 0;
237 FT_Request_Size(face, &rq);
238 m->ascender /= mscale;
239 m->descender /= mscale;
244 * \brief Set font size
246 void ass_font_set_size(ASS_Font *font, double size)
249 if (font->size != size) {
251 for (i = 0; i < font->n_faces; ++i)
252 face_set_size(font->faces[i], size);
257 * \brief Get maximal font ascender and descender.
258 * \param ch character code
259 * The values are extracted from the font face that provides glyphs for the given character
261 void ass_font_get_asc_desc(ASS_Font *font, uint32_t ch, int *asc,
265 for (i = 0; i < font->n_faces; ++i) {
266 FT_Face face = font->faces[i];
267 TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2);
268 if (FT_Get_Char_Index(face, ch)) {
269 int y_scale = face->size->metrics.y_scale;
271 *asc = FT_MulFix(os2->usWinAscent, y_scale);
272 *desc = FT_MulFix(os2->usWinDescent, y_scale);
274 *asc = FT_MulFix(face->ascender, y_scale);
275 *desc = FT_MulFix(-face->descender, y_scale);
277 if (font->desc.vertical && ch >= VERTICAL_LOWER_BOUND) {
278 *asc = FT_MulFix(face->max_advance_width, y_scale);
288 * Strike a glyph with a horizontal line; it's possible to underline it
289 * and/or strike through it. For the line's position and size, truetype
290 * tables are consulted. Obviously this relies on the data in the tables
294 static int ass_strike_outline_glyph(FT_Face face, ASS_Font *font,
295 FT_Glyph glyph, int under, int through)
297 TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2);
298 TT_Postscript *ps = FT_Get_Sfnt_Table(face, ft_sfnt_post);
299 FT_Outline *ol = &((FT_OutlineGlyph) glyph)->outline;
300 int bear, advance, y_scale, i, dir;
302 if (!under && !through)
306 i = (under ? 4 : 0) + (through ? 4 : 0);
307 ol->points = realloc(ol->points, sizeof(FT_Vector) *
309 ol->tags = realloc(ol->tags, ol->n_points + i);
310 i = !!under + !!through;
311 ol->contours = realloc(ol->contours, sizeof(short) *
312 (ol->n_contours + i));
314 // If the bearing is negative, the glyph starts left of the current
316 bear = FFMIN(face->glyph->metrics.horiBearingX, 0);
317 // We're adding half a pixel to avoid small gaps
318 advance = d16_to_d6(glyph->advance.x) + 32;
319 y_scale = face->size->metrics.y_scale;
321 // Reverse drawing direction for non-truetype fonts
322 dir = FT_Outline_Get_Orientation(ol);
324 // Add points to the outline
327 pos = FT_MulFix(ps->underlinePosition, y_scale * font->scale_y);
328 size = FT_MulFix(ps->underlineThickness,
329 y_scale * font->scale_y / 2);
331 if (pos > 0 || size <= 0)
334 FT_Vector points[4] = {
335 {.x = bear, .y = pos + size},
336 {.x = advance, .y = pos + size},
337 {.x = advance, .y = pos - size},
338 {.x = bear, .y = pos - size},
341 if (dir == FT_ORIENTATION_TRUETYPE) {
342 for (i = 0; i < 4; i++) {
343 ol->points[ol->n_points] = points[i];
344 ol->tags[ol->n_points++] = 1;
347 for (i = 3; i >= 0; i--) {
348 ol->points[ol->n_points] = points[i];
349 ol->tags[ol->n_points++] = 1;
353 ol->contours[ol->n_contours++] = ol->n_points - 1;
356 if (through && os2) {
358 pos = FT_MulFix(os2->yStrikeoutPosition, y_scale * font->scale_y);
359 size = FT_MulFix(os2->yStrikeoutSize, y_scale * font->scale_y / 2);
361 if (pos < 0 || size <= 0)
364 FT_Vector points[4] = {
365 {.x = bear, .y = pos + size},
366 {.x = advance, .y = pos + size},
367 {.x = advance, .y = pos - size},
368 {.x = bear, .y = pos - size},
371 if (dir == FT_ORIENTATION_TRUETYPE) {
372 for (i = 0; i < 4; i++) {
373 ol->points[ol->n_points] = points[i];
374 ol->tags[ol->n_points++] = 1;
377 for (i = 3; i >= 0; i--) {
378 ol->points[ol->n_points] = points[i];
379 ol->tags[ol->n_points++] = 1;
383 ol->contours[ol->n_contours++] = ol->n_points - 1;
389 void outline_copy(FT_Library lib, FT_Outline *source, FT_Outline **dest)
391 if (source == NULL) {
395 *dest = calloc(1, sizeof(**dest));
397 FT_Outline_New(lib, source->n_points, source->n_contours, *dest);
398 FT_Outline_Copy(source, *dest);
401 void outline_free(FT_Library lib, FT_Outline *outline)
404 FT_Outline_Done(lib, outline);
409 * Slightly embold a glyph without touching its metrics
411 static void ass_glyph_embolden(FT_GlyphSlot slot)
415 if (slot->format != FT_GLYPH_FORMAT_OUTLINE)
418 str = FT_MulFix(slot->face->units_per_EM,
419 slot->face->size->metrics.y_scale) / 64;
421 FT_Outline_Embolden(&slot->outline, str);
426 * \param ch character code
428 FT_Glyph ass_font_get_glyph(void *fontconfig_priv, ASS_Font *font,
429 uint32_t ch, ASS_Hinting hinting, int deco)
437 int vertical = font->desc.vertical;
441 // Handle NBSP like a regular space when rendering the glyph
444 if (font->n_faces == 0)
447 for (i = 0; i < font->n_faces; ++i) {
448 face = font->faces[i];
449 index = FT_Get_Char_Index(face, ch);
454 #ifdef CONFIG_FONTCONFIG
457 ass_msg(font->library, MSGL_INFO,
458 "Glyph 0x%X not found, selecting one more "
459 "font for (%s, %d, %d)", ch, font->desc.family,
460 font->desc.bold, font->desc.italic);
461 face_idx = add_face(fontconfig_priv, font, ch);
463 face = font->faces[face_idx];
464 index = FT_Get_Char_Index(face, ch);
465 if (index == 0 && face->num_charmaps > 0) {
467 ass_msg(font->library, MSGL_WARN,
468 "Glyph 0x%X not found, broken font? Trying all charmaps", ch);
469 for (i = 0; i < face->num_charmaps; i++) {
470 FT_Set_Charmap(face, face->charmaps[i]);
471 if ((index = FT_Get_Char_Index(face, ch)) != 0) break;
475 ass_msg(font->library, MSGL_ERR,
476 "Glyph 0x%X not found in font for (%s, %d, %d)",
477 ch, font->desc.family, font->desc.bold,
484 flags = FT_LOAD_NO_BITMAP | FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH
485 | FT_LOAD_IGNORE_TRANSFORM;
487 case ASS_HINTING_NONE:
488 flags |= FT_LOAD_NO_HINTING;
490 case ASS_HINTING_LIGHT:
491 flags |= FT_LOAD_FORCE_AUTOHINT | FT_LOAD_TARGET_LIGHT;
493 case ASS_HINTING_NORMAL:
494 flags |= FT_LOAD_FORCE_AUTOHINT;
496 case ASS_HINTING_NATIVE:
500 error = FT_Load_Glyph(face, index, flags);
502 ass_msg(font->library, MSGL_WARN, "Error loading glyph, index %d",
506 if (!(face->style_flags & FT_STYLE_FLAG_ITALIC) &&
507 (font->desc.italic > 55)) {
508 FT_GlyphSlot_Oblique(face->glyph);
511 if (!(face->style_flags & FT_STYLE_FLAG_BOLD) &&
512 (font->desc.bold > 80)) {
513 ass_glyph_embolden(face->glyph);
515 error = FT_Get_Glyph(face->glyph, &glyph);
517 ass_msg(font->library, MSGL_WARN, "Error loading glyph, index %d",
522 // Rotate glyph, if needed
523 if (vertical && ch >= VERTICAL_LOWER_BOUND) {
524 FT_Matrix m = { 0, double_to_d16(-1.0), double_to_d16(1.0), 0 };
525 FT_Outline_Transform(&((FT_OutlineGlyph) glyph)->outline, &m);
526 FT_Outline_Translate(&((FT_OutlineGlyph) glyph)->outline,
527 face->glyph->metrics.vertAdvance,
529 glyph->advance.x = face->glyph->linearVertAdvance;
532 // Apply scaling and shift
533 FT_Matrix scale = { double_to_d16(font->scale_x), 0, 0,
534 double_to_d16(font->scale_y) };
535 FT_Outline *outl = &((FT_OutlineGlyph) glyph)->outline;
536 FT_Outline_Transform(outl, &scale);
537 FT_Outline_Translate(outl, font->v.x, font->v.y);
538 glyph->advance.x *= font->scale_x;
540 ass_strike_outline_glyph(face, font, glyph, deco & DECO_UNDERLINE,
541 deco & DECO_STRIKETHROUGH);
547 * \brief Get kerning for the pair of glyphs.
549 FT_Vector ass_font_get_kerning(ASS_Font *font, uint32_t c1, uint32_t c2)
551 FT_Vector v = { 0, 0 };
554 if (font->desc.vertical)
557 for (i = 0; i < font->n_faces; ++i) {
558 FT_Face face = font->faces[i];
559 int i1 = FT_Get_Char_Index(face, c1);
560 int i2 = FT_Get_Char_Index(face, c2);
562 if (FT_HAS_KERNING(face))
563 FT_Get_Kerning(face, i1, i2, FT_KERNING_DEFAULT, &v);
566 if (i1 || i2) // these glyphs are from different font faces, no kerning information
573 * \brief Deallocate ASS_Font
575 void ass_font_free(ASS_Font *font)
578 for (i = 0; i < font->n_faces; ++i)
580 FT_Done_Face(font->faces[i]);
581 free(font->desc.family);
586 * \brief Calculate the cbox of a series of points
589 get_contour_cbox(FT_BBox *box, FT_Vector *points, int start, int end)
591 box->xMin = box->yMin = INT_MAX;
592 box->xMax = box->yMax = INT_MIN;
595 for (i = start; i <= end; i++) {
596 box->xMin = (points[i].x < box->xMin) ? points[i].x : box->xMin;
597 box->xMax = (points[i].x > box->xMax) ? points[i].x : box->xMax;
598 box->yMin = (points[i].y < box->yMin) ? points[i].y : box->yMin;
599 box->yMax = (points[i].y > box->yMax) ? points[i].y : box->yMax;
604 * \brief Determine winding direction of a contour
605 * \return direction; 0 = clockwise
607 static int get_contour_direction(FT_Vector *points, int start, int end)
611 int x = points[start].x;
612 int y = points[start].y;
613 for (i = start + 1; i <= end; i++) {
614 sum += x * (points[i].y - y) - y * (points[i].x - x);
618 sum += x * (points[start].y - y) - y * (points[start].x - x);
623 * \brief Fix-up stroker result for huge borders by removing inside contours
624 * that would reverse in size
626 void fix_freetype_stroker(FT_Outline *outline, int border_x, int border_y)
628 int nc = outline->n_contours;
631 char *valid_cont = malloc(nc);
634 FT_BBox *boxes = malloc(nc * sizeof(FT_BBox));
636 int inside_direction;
638 inside_direction = FT_Outline_Get_Orientation(outline) ==
639 FT_ORIENTATION_TRUETYPE;
641 // create a list of cboxes of the contours
642 for (i = 0; i < nc; i++) {
644 end = outline->contours[i];
645 get_contour_cbox(&boxes[i], outline->points, start, end);
648 // for each contour, check direction and whether it's "outside"
649 // or contained in another contour
651 for (i = 0; i < nc; i++) {
653 end = outline->contours[i];
654 int dir = get_contour_direction(outline->points, start, end);
656 if (dir == inside_direction) {
657 for (j = 0; j < nc; j++) {
660 if (boxes[i].xMin >= boxes[j].xMin &&
661 boxes[i].xMax <= boxes[j].xMax &&
662 boxes[i].yMin >= boxes[j].yMin &&
663 boxes[i].yMax <= boxes[j].yMax)
666 /* "inside" contour but we can't find anything it could be
667 * inside of - assume the font is buggy and it should be
668 * an "outside" contour, and reverse it */
669 for (j = 0; j < (end + 1 - start) / 2; j++) {
670 FT_Vector temp = outline->points[start + j];
671 char temp2 = outline->tags[start + j];
672 outline->points[start + j] = outline->points[end - j];
673 outline->points[end - j] = temp;
674 outline->tags[start + j] = outline->tags[end - j];
675 outline->tags[end - j] = temp2;
680 if (dir == inside_direction) {
682 get_contour_cbox(&box, outline->points, start, end);
683 int width = box.xMax - box.xMin;
684 int height = box.yMax - box.yMin;
685 if (width < border_x * 2 || height < border_y * 2) {
692 // zero-out contours that can be removed; much simpler than copying
694 for (i = 0; i < nc; i++) {
697 begin = (i == 0) ? 0 : outline->contours[i - 1] + 1;
698 stop = outline->contours[i];
699 for (j = begin; j <= stop; j++) {
700 outline->points[j].x = 0;
701 outline->points[j].y = 0;
702 outline->tags[j] = 0;