/* * Copyright (C) 2006 Evgeniy Stepanov <eugeni.stepanov@gmail.com> * * This file is part of libass. * * libass is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * libass is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with libass; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include <inttypes.h> #include <ft2build.h> #include FT_FREETYPE_H #include FT_SYNTHESIS_H #include FT_GLYPH_H #include FT_TRUETYPE_TABLES_H #include FT_OUTLINE_H #include "ass.h" #include "ass_library.h" #include "ass_font.h" #include "ass_bitmap.h" #include "ass_cache.h" #include "ass_fontconfig.h" #include "ass_utils.h" /** * Select Microfost Unicode CharMap, if the font has one. * Otherwise, let FreeType decide. */ static void charmap_magic(ASS_Library *library, FT_Face face) { int i; for (i = 0; i < face->num_charmaps; ++i) { FT_CharMap cmap = face->charmaps[i]; unsigned pid = cmap->platform_id; unsigned eid = cmap->encoding_id; if (pid == 3 /*microsoft */ && (eid == 1 /*unicode bmp */ || eid == 10 /*full unicode */ )) { FT_Set_Charmap(face, cmap); return; } } if (!face->charmap) { if (face->num_charmaps == 0) { ass_msg(library, MSGL_WARN, "Font face with no charmaps"); return; } ass_msg(library, MSGL_WARN, "No charmap autodetected, trying the first one"); FT_Set_Charmap(face, face->charmaps[0]); return; } } static void update_transform(ASS_Font *font) { int i; FT_Matrix m; m.xx = double_to_d16(font->scale_x); m.yy = double_to_d16(font->scale_y); m.xy = m.yx = 0; for (i = 0; i < font->n_faces; ++i) FT_Set_Transform(font->faces[i], &m, &font->v); } /** * \brief find a memory font by name */ static int find_font(ASS_Library *library, char *name) { int i; for (i = 0; i < library->num_fontdata; ++i) if (strcasecmp(name, library->fontdata[i].name) == 0) return i; return -1; } static void face_set_size(FT_Face face, double size); static void buggy_font_workaround(FT_Face face) { // Some fonts have zero Ascender/Descender fields in 'hhea' table. // In this case, get the information from 'os2' table or, as // a last resort, from face.bbox. if (face->ascender + face->descender == 0 || face->height == 0) { TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2); if (os2) { face->ascender = os2->sTypoAscender; face->descender = os2->sTypoDescender; face->height = face->ascender - face->descender; } else { face->ascender = face->bbox.yMax; face->descender = face->bbox.yMin; face->height = face->ascender - face->descender; } } } /** * \brief Select a face with the given charcode and add it to ASS_Font * \return index of the new face in font->faces, -1 if failed */ static int add_face(void *fc_priv, ASS_Font *font, uint32_t ch) { char *path; int index; FT_Face face; int error; int mem_idx; if (font->n_faces == ASS_FONT_MAX_FACES) return -1; path = fontconfig_select(font->library, fc_priv, font->desc.family, font->desc.treat_family_as_pattern, font->desc.bold, font->desc.italic, &index, ch); if (!path) return -1; mem_idx = find_font(font->library, path); if (mem_idx >= 0) { error = FT_New_Memory_Face(font->ftlibrary, (unsigned char *) font->library-> fontdata[mem_idx].data, font->library->fontdata[mem_idx].size, 0, &face); if (error) { ass_msg(font->library, MSGL_WARN, "Error opening memory font: '%s'", path); free(path); return -1; } } else { error = FT_New_Face(font->ftlibrary, path, index, &face); if (error) { ass_msg(font->library, MSGL_WARN, "Error opening font: '%s', %d", path, index); free(path); return -1; } } charmap_magic(font->library, face); buggy_font_workaround(face); font->faces[font->n_faces++] = face; update_transform(font); face_set_size(face, font->size); free(path); return font->n_faces - 1; } /** * \brief Create a new ASS_Font according to "desc" argument */ ASS_Font *ass_font_new(void *font_cache, ASS_Library *library, FT_Library ftlibrary, void *fc_priv, ASS_FontDesc *desc) { int error; ASS_Font *fontp; ASS_Font font; fontp = ass_font_cache_find((Hashmap *) font_cache, desc); if (fontp) return fontp; font.library = library; font.ftlibrary = ftlibrary; font.n_faces = 0; font.desc.family = strdup(desc->family); font.desc.treat_family_as_pattern = desc->treat_family_as_pattern; font.desc.bold = desc->bold; font.desc.italic = desc->italic; font.scale_x = font.scale_y = 1.; font.v.x = font.v.y = 0; font.size = 0.; error = add_face(fc_priv, &font, 0); if (error == -1) { free(font.desc.family); return 0; } else return ass_font_cache_add((Hashmap *) font_cache, &font); } /** * \brief Set font transformation matrix and shift vector **/ void ass_font_set_transform(ASS_Font *font, double scale_x, double scale_y, FT_Vector *v) { font->scale_x = scale_x; font->scale_y = scale_y; if (v) { font->v.x = v->x; font->v.y = v->y; } update_transform(font); } static void face_set_size(FT_Face face, double size) { TT_HoriHeader *hori = FT_Get_Sfnt_Table(face, ft_sfnt_hhea); TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2); double mscale = 1.; FT_Size_RequestRec rq; FT_Size_Metrics *m = &face->size->metrics; // VSFilter uses metrics from TrueType OS/2 table // The idea was borrowed from asa (http://asa.diac24.net) if (hori && os2) { int hori_height = hori->Ascender - hori->Descender; int os2_height = os2->usWinAscent + os2->usWinDescent; if (hori_height && os2_height) mscale = (double) hori_height / os2_height; } memset(&rq, 0, sizeof(rq)); rq.type = FT_SIZE_REQUEST_TYPE_REAL_DIM; rq.width = 0; rq.height = double_to_d6(size * mscale); rq.horiResolution = rq.vertResolution = 0; FT_Request_Size(face, &rq); m->ascender /= mscale; m->descender /= mscale; m->height /= mscale; } /** * \brief Set font size **/ void ass_font_set_size(ASS_Font *font, double size) { int i; if (font->size != size) { font->size = size; for (i = 0; i < font->n_faces; ++i) face_set_size(font->faces[i], size); } } /** * \brief Get maximal font ascender and descender. * \param ch character code * The values are extracted from the font face that provides glyphs for the given character **/ void ass_font_get_asc_desc(ASS_Font *font, uint32_t ch, int *asc, int *desc) { int i; for (i = 0; i < font->n_faces; ++i) { FT_Face face = font->faces[i]; TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2); if (FT_Get_Char_Index(face, ch)) { int y_scale = face->size->metrics.y_scale; if (os2) { *asc = FT_MulFix(os2->usWinAscent, y_scale); *desc = FT_MulFix(os2->usWinDescent, y_scale); } else { *asc = FT_MulFix(face->ascender, y_scale); *desc = FT_MulFix(-face->descender, y_scale); } return; } } *asc = *desc = 0; } /* * Strike a glyph with a horizontal line; it's possible to underline it * and/or strike through it. For the line's position and size, truetype * tables are consulted. Obviously this relies on the data in the tables * being accurate. * */ static int ass_strike_outline_glyph(FT_Face face, ASS_Font *font, FT_Glyph glyph, int under, int through) { TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2); TT_Postscript *ps = FT_Get_Sfnt_Table(face, ft_sfnt_post); FT_Outline *ol = &((FT_OutlineGlyph) glyph)->outline; int bear, advance, y_scale, i, dir; if (!under && !through) return 0; // Grow outline i = (under ? 4 : 0) + (through ? 4 : 0); ol->points = realloc(ol->points, sizeof(FT_Vector) * (ol->n_points + i)); ol->tags = realloc(ol->tags, ol->n_points + i); i = !!under + !!through; ol->contours = realloc(ol->contours, sizeof(short) * (ol->n_contours + i)); // If the bearing is negative, the glyph starts left of the current // pen position bear = FFMIN(face->glyph->metrics.horiBearingX, 0); // We're adding half a pixel to avoid small gaps advance = d16_to_d6(glyph->advance.x) + 32; y_scale = face->size->metrics.y_scale; // Reverse drawing direction for non-truetype fonts dir = FT_Outline_Get_Orientation(ol); // Add points to the outline if (under && ps) { int pos, size; pos = FT_MulFix(ps->underlinePosition, y_scale * font->scale_y); size = FT_MulFix(ps->underlineThickness, y_scale * font->scale_y / 2); if (pos > 0 || size <= 0) return 1; FT_Vector points[4] = { {.x = bear, .y = pos + size}, {.x = advance, .y = pos + size}, {.x = advance, .y = pos - size}, {.x = bear, .y = pos - size}, }; if (dir == FT_ORIENTATION_TRUETYPE) { for (i = 0; i < 4; i++) { ol->points[ol->n_points] = points[i]; ol->tags[ol->n_points++] = 1; } } else { for (i = 3; i >= 0; i--) { ol->points[ol->n_points] = points[i]; ol->tags[ol->n_points++] = 1; } } ol->contours[ol->n_contours++] = ol->n_points - 1; } if (through && os2) { int pos, size; pos = FT_MulFix(os2->yStrikeoutPosition, y_scale * font->scale_y); size = FT_MulFix(os2->yStrikeoutSize, y_scale * font->scale_y / 2); if (pos < 0 || size <= 0) return 1; FT_Vector points[4] = { {.x = bear, .y = pos + size}, {.x = advance, .y = pos + size}, {.x = advance, .y = pos - size}, {.x = bear, .y = pos - size}, }; if (dir == FT_ORIENTATION_TRUETYPE) { for (i = 0; i < 4; i++) { ol->points[ol->n_points] = points[i]; ol->tags[ol->n_points++] = 1; } } else { for (i = 3; i >= 0; i--) { ol->points[ol->n_points] = points[i]; ol->tags[ol->n_points++] = 1; } } ol->contours[ol->n_contours++] = ol->n_points - 1; } return 0; } /** * Slightly embold a glyph without touching its metrics */ static void ass_glyph_embolden(FT_GlyphSlot slot) { int str; if (slot->format != FT_GLYPH_FORMAT_OUTLINE) return; str = FT_MulFix(slot->face->units_per_EM, slot->face->size->metrics.y_scale) / 64; FT_Outline_Embolden(&slot->outline, str); } /** * \brief Get a glyph * \param ch character code **/ FT_Glyph ass_font_get_glyph(void *fontconfig_priv, ASS_Font *font, uint32_t ch, ASS_Hinting hinting, int deco) { int error; int index = 0; int i; FT_Glyph glyph; FT_Face face = 0; int flags = 0; if (ch < 0x20) return 0; // Handle NBSP like a regular space when rendering the glyph if (ch == 0xa0) ch = ' '; if (font->n_faces == 0) return 0; for (i = 0; i < font->n_faces; ++i) { face = font->faces[i]; index = FT_Get_Char_Index(face, ch); if (index) break; } #ifdef CONFIG_FONTCONFIG if (index == 0) { int face_idx; ass_msg(font->library, MSGL_INFO, "Glyph 0x%X not found, selecting one more " "font for (%s, %d, %d)", ch, font->desc.family, font->desc.bold, font->desc.italic); face_idx = add_face(fontconfig_priv, font, ch); if (face_idx >= 0) { face = font->faces[face_idx]; index = FT_Get_Char_Index(face, ch); if (index == 0) { ass_msg(font->library, MSGL_ERR, "Glyph 0x%X not found in font for (%s, %d, %d)", ch, font->desc.family, font->desc.bold, font->desc.italic); } } } #endif switch (hinting) { case ASS_HINTING_NONE: flags = FT_LOAD_NO_HINTING; break; case ASS_HINTING_LIGHT: flags = FT_LOAD_FORCE_AUTOHINT | FT_LOAD_TARGET_LIGHT; break; case ASS_HINTING_NORMAL: flags = FT_LOAD_FORCE_AUTOHINT; break; case ASS_HINTING_NATIVE: flags = 0; break; } error = FT_Load_Glyph(face, index, FT_LOAD_NO_BITMAP | flags); if (error) { ass_msg(font->library, MSGL_WARN, "Error loading glyph, index %d", index); return 0; } if (!(face->style_flags & FT_STYLE_FLAG_ITALIC) && (font->desc.italic > 55)) { FT_GlyphSlot_Oblique(face->glyph); } if (!(face->style_flags & FT_STYLE_FLAG_BOLD) && (font->desc.bold > 80)) { ass_glyph_embolden(face->glyph); } error = FT_Get_Glyph(face->glyph, &glyph); if (error) { ass_msg(font->library, MSGL_WARN, "Error loading glyph, index %d", index); return 0; } ass_strike_outline_glyph(face, font, glyph, deco & DECO_UNDERLINE, deco & DECO_STRIKETHROUGH); return glyph; } /** * \brief Get kerning for the pair of glyphs. **/ FT_Vector ass_font_get_kerning(ASS_Font *font, uint32_t c1, uint32_t c2) { FT_Vector v = { 0, 0 }; int i; for (i = 0; i < font->n_faces; ++i) { FT_Face face = font->faces[i]; int i1 = FT_Get_Char_Index(face, c1); int i2 = FT_Get_Char_Index(face, c2); if (i1 && i2) { if (FT_HAS_KERNING(face)) FT_Get_Kerning(face, i1, i2, FT_KERNING_DEFAULT, &v); return v; } if (i1 || i2) // these glyphs are from different font faces, no kerning information return v; } return v; } /** * \brief Deallocate ASS_Font **/ void ass_font_free(ASS_Font *font) { int i; for (i = 0; i < font->n_faces; ++i) if (font->faces[i]) FT_Done_Face(font->faces[i]); if (font->desc.family) free(font->desc.family); free(font); }