diff options
Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-font.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-font.cc | 662 |
1 files changed, 662 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-font.cc b/gfx/harfbuzz/src/hb-ot-font.cc new file mode 100644 index 000000000..5be055d34 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-font.cc @@ -0,0 +1,662 @@ +/* + * Copyright © 2011,2014 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Behdad Esfahbod, Roozbeh Pournader + */ + +#include "hb-private.hh" + +#include "hb-ot.h" + +#include "hb-font-private.hh" + +#include "hb-ot-cmap-table.hh" +#include "hb-ot-cbdt-table.hh" +#include "hb-ot-glyf-table.hh" +#include "hb-ot-head-table.hh" +#include "hb-ot-hhea-table.hh" +#include "hb-ot-hmtx-table.hh" +#include "hb-ot-os2-table.hh" +//#include "hb-ot-post-table.hh" + + +struct hb_ot_face_metrics_accelerator_t +{ + unsigned int num_metrics; + unsigned int num_advances; + unsigned int default_advance; + unsigned short ascender; + unsigned short descender; + unsigned short line_gap; + bool has_font_extents; + + const OT::_mtx *table; + hb_blob_t *blob; + + inline void init (hb_face_t *face, + hb_tag_t _hea_tag, + hb_tag_t _mtx_tag, + hb_tag_t os2_tag, + unsigned int default_advance = 0) + { + this->default_advance = default_advance ? default_advance : face->get_upem (); + + bool got_font_extents = false; + if (os2_tag) + { + hb_blob_t *os2_blob = OT::Sanitizer<OT::os2>::sanitize (face->reference_table (os2_tag)); + const OT::os2 *os2 = OT::Sanitizer<OT::os2>::lock_instance (os2_blob); +#define USE_TYPO_METRICS (1u<<7) + if (0 != (os2->fsSelection & USE_TYPO_METRICS)) + { + this->ascender = os2->sTypoAscender; + this->descender = os2->sTypoDescender; + this->line_gap = os2->sTypoLineGap; + got_font_extents = (this->ascender | this->descender) != 0; + } + hb_blob_destroy (os2_blob); + } + + hb_blob_t *_hea_blob = OT::Sanitizer<OT::_hea>::sanitize (face->reference_table (_hea_tag)); + const OT::_hea *_hea = OT::Sanitizer<OT::_hea>::lock_instance (_hea_blob); + this->num_advances = _hea->numberOfLongMetrics; + if (!got_font_extents) + { + this->ascender = _hea->ascender; + this->descender = _hea->descender; + this->line_gap = _hea->lineGap; + got_font_extents = (this->ascender | this->descender) != 0; + } + hb_blob_destroy (_hea_blob); + + this->has_font_extents = got_font_extents; + + this->blob = OT::Sanitizer<OT::_mtx>::sanitize (face->reference_table (_mtx_tag)); + + /* Cap num_metrics() and num_advances() based on table length. */ + unsigned int len = hb_blob_get_length (this->blob); + if (unlikely (this->num_advances * 4 > len)) + this->num_advances = len / 4; + this->num_metrics = this->num_advances + (len - 4 * this->num_advances) / 2; + + /* We MUST set num_metrics to zero if num_advances is zero. + * Our get_advance() depends on that. */ + if (unlikely (!this->num_advances)) + { + this->num_metrics = this->num_advances = 0; + hb_blob_destroy (this->blob); + this->blob = hb_blob_get_empty (); + } + this->table = OT::Sanitizer<OT::_mtx>::lock_instance (this->blob); + } + + inline void fini (void) + { + hb_blob_destroy (this->blob); + } + + inline unsigned int get_advance (hb_codepoint_t glyph) const + { + if (unlikely (glyph >= this->num_metrics)) + { + /* If this->num_metrics is zero, it means we don't have the metrics table + * for this direction: return default advance. Otherwise, it means that the + * glyph index is out of bound: return zero. */ + if (this->num_metrics) + return 0; + else + return this->default_advance; + } + + if (glyph >= this->num_advances) + glyph = this->num_advances - 1; + + return this->table->longMetric[glyph].advance; + } +}; + +struct hb_ot_face_glyf_accelerator_t +{ + bool short_offset; + unsigned int num_glyphs; + const OT::loca *loca; + const OT::glyf *glyf; + hb_blob_t *loca_blob; + hb_blob_t *glyf_blob; + unsigned int glyf_len; + + inline void init (hb_face_t *face) + { + hb_blob_t *head_blob = OT::Sanitizer<OT::head>::sanitize (face->reference_table (HB_OT_TAG_head)); + const OT::head *head = OT::Sanitizer<OT::head>::lock_instance (head_blob); + if ((unsigned int) head->indexToLocFormat > 1 || head->glyphDataFormat != 0) + { + /* Unknown format. Leave num_glyphs=0, that takes care of disabling us. */ + hb_blob_destroy (head_blob); + return; + } + this->short_offset = 0 == head->indexToLocFormat; + hb_blob_destroy (head_blob); + + this->loca_blob = OT::Sanitizer<OT::loca>::sanitize (face->reference_table (HB_OT_TAG_loca)); + this->loca = OT::Sanitizer<OT::loca>::lock_instance (this->loca_blob); + this->glyf_blob = OT::Sanitizer<OT::glyf>::sanitize (face->reference_table (HB_OT_TAG_glyf)); + this->glyf = OT::Sanitizer<OT::glyf>::lock_instance (this->glyf_blob); + + this->num_glyphs = MAX (1u, hb_blob_get_length (this->loca_blob) / (this->short_offset ? 2 : 4)) - 1; + this->glyf_len = hb_blob_get_length (this->glyf_blob); + } + + inline void fini (void) + { + hb_blob_destroy (this->loca_blob); + hb_blob_destroy (this->glyf_blob); + } + + inline bool get_extents (hb_codepoint_t glyph, + hb_glyph_extents_t *extents) const + { + if (unlikely (glyph >= this->num_glyphs)) + return false; + + unsigned int start_offset, end_offset; + if (this->short_offset) + { + start_offset = 2 * this->loca->u.shortsZ[glyph]; + end_offset = 2 * this->loca->u.shortsZ[glyph + 1]; + } + else + { + start_offset = this->loca->u.longsZ[glyph]; + end_offset = this->loca->u.longsZ[glyph + 1]; + } + + if (start_offset > end_offset || end_offset > this->glyf_len) + return false; + + if (end_offset - start_offset < OT::glyfGlyphHeader::static_size) + return true; /* Empty glyph; zero extents. */ + + const OT::glyfGlyphHeader &glyph_header = OT::StructAtOffset<OT::glyfGlyphHeader> (this->glyf, start_offset); + + extents->x_bearing = MIN (glyph_header.xMin, glyph_header.xMax); + extents->y_bearing = MAX (glyph_header.yMin, glyph_header.yMax); + extents->width = MAX (glyph_header.xMin, glyph_header.xMax) - extents->x_bearing; + extents->height = MIN (glyph_header.yMin, glyph_header.yMax) - extents->y_bearing; + + return true; + } +}; + +struct hb_ot_face_cbdt_accelerator_t +{ + hb_blob_t *cblc_blob; + hb_blob_t *cbdt_blob; + const OT::CBLC *cblc; + const OT::CBDT *cbdt; + + unsigned int cbdt_len; + float upem; + + inline void init (hb_face_t *face) + { + upem = face->get_upem(); + + cblc_blob = OT::Sanitizer<OT::CBLC>::sanitize (face->reference_table (HB_OT_TAG_CBLC)); + cbdt_blob = OT::Sanitizer<OT::CBDT>::sanitize (face->reference_table (HB_OT_TAG_CBDT)); + cbdt_len = hb_blob_get_length (cbdt_blob); + + if (hb_blob_get_length (cblc_blob) == 0) { + cblc = NULL; + cbdt = NULL; + return; /* Not a bitmap font. */ + } + cblc = OT::Sanitizer<OT::CBLC>::lock_instance (cblc_blob); + cbdt = OT::Sanitizer<OT::CBDT>::lock_instance (cbdt_blob); + + } + + inline void fini (void) + { + hb_blob_destroy (this->cblc_blob); + hb_blob_destroy (this->cbdt_blob); + } + + inline bool get_extents (hb_codepoint_t glyph, hb_glyph_extents_t *extents) const + { + unsigned int x_ppem = upem, y_ppem = upem; /* TODO Use font ppem if available. */ + + if (cblc == NULL) + return false; // Not a color bitmap font. + + const OT::IndexSubtableRecord *subtable_record = this->cblc->find_table(glyph, &x_ppem, &y_ppem); + if (subtable_record == NULL) + return false; + + if (subtable_record->get_extents (extents)) + return true; + + unsigned int image_offset = 0, image_length = 0, image_format = 0; + if (!subtable_record->get_image_data (glyph, &image_offset, &image_length, &image_format)) + return false; + + { + /* TODO Move the following into CBDT struct when adding more formats. */ + + if (unlikely (image_offset > cbdt_len || cbdt_len - image_offset < image_length)) + return false; + + switch (image_format) + { + case 17: { + if (unlikely (image_length < OT::GlyphBitmapDataFormat17::min_size)) + return false; + + const OT::GlyphBitmapDataFormat17& glyphFormat17 = + OT::StructAtOffset<OT::GlyphBitmapDataFormat17> (this->cbdt, image_offset); + glyphFormat17.glyphMetrics.get_extents (extents); + } + break; + default: + // TODO: Support other image formats. + return false; + } + } + + /* Convert to the font units. */ + extents->x_bearing *= upem / (float) x_ppem; + extents->y_bearing *= upem / (float) y_ppem; + extents->width *= upem / (float) x_ppem; + extents->height *= upem / (float) y_ppem; + + return true; + } +}; + +typedef bool (*hb_cmap_get_glyph_func_t) (const void *obj, + hb_codepoint_t codepoint, + hb_codepoint_t *glyph); + +template <typename Type> +static inline bool get_glyph_from (const void *obj, + hb_codepoint_t codepoint, + hb_codepoint_t *glyph) +{ + const Type *typed_obj = (const Type *) obj; + return typed_obj->get_glyph (codepoint, glyph); +} + +template <typename Type> +static inline bool get_glyph_from_symbol (const void *obj, + hb_codepoint_t codepoint, + hb_codepoint_t *glyph) +{ + const Type *typed_obj = (const Type *) obj; + if (likely (typed_obj->get_glyph (codepoint, glyph))) + return true; + + if (codepoint <= 0x00FFu) + { + /* For symbol-encoded OpenType fonts, we duplicate the + * U+F000..F0FF range at U+0000..U+00FF. That's what + * Windows seems to do, and that's hinted about at: + * http://www.microsoft.com/typography/otspec/recom.htm + * under "Non-Standard (Symbol) Fonts". */ + return typed_obj->get_glyph (0xF000u + codepoint, glyph); + } + + return false; +} + +struct hb_ot_face_cmap_accelerator_t +{ + hb_cmap_get_glyph_func_t get_glyph_func; + const void *get_glyph_data; + OT::CmapSubtableFormat4::accelerator_t format4_accel; + + const OT::CmapSubtableFormat14 *uvs_table; + hb_blob_t *blob; + + inline void init (hb_face_t *face) + { + this->blob = OT::Sanitizer<OT::cmap>::sanitize (face->reference_table (HB_OT_TAG_cmap)); + const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (this->blob); + const OT::CmapSubtable *subtable = NULL; + const OT::CmapSubtableFormat14 *subtable_uvs = NULL; + + bool symbol = false; + /* 32-bit subtables. */ + if (!subtable) subtable = cmap->find_subtable (3, 10); + if (!subtable) subtable = cmap->find_subtable (0, 6); + if (!subtable) subtable = cmap->find_subtable (0, 4); + /* 16-bit subtables. */ + if (!subtable) subtable = cmap->find_subtable (3, 1); + if (!subtable) subtable = cmap->find_subtable (0, 3); + if (!subtable) subtable = cmap->find_subtable (0, 2); + if (!subtable) subtable = cmap->find_subtable (0, 1); + if (!subtable) subtable = cmap->find_subtable (0, 0); + if (!subtable) + { + subtable = cmap->find_subtable (3, 0); + if (subtable) symbol = true; + } + /* Meh. */ + if (!subtable) subtable = &OT::Null(OT::CmapSubtable); + + /* UVS subtable. */ + if (!subtable_uvs) + { + const OT::CmapSubtable *st = cmap->find_subtable (0, 5); + if (st && st->u.format == 14) + subtable_uvs = &st->u.format14; + } + /* Meh. */ + if (!subtable_uvs) subtable_uvs = &OT::Null(OT::CmapSubtableFormat14); + + this->uvs_table = subtable_uvs; + + this->get_glyph_data = subtable; + if (unlikely (symbol)) + this->get_glyph_func = get_glyph_from_symbol<OT::CmapSubtable>; + else + switch (subtable->u.format) { + /* Accelerate format 4 and format 12. */ + default: this->get_glyph_func = get_glyph_from<OT::CmapSubtable>; break; + case 12: this->get_glyph_func = get_glyph_from<OT::CmapSubtableFormat12>; break; + case 4: + { + this->format4_accel.init (&subtable->u.format4); + this->get_glyph_data = &this->format4_accel; + this->get_glyph_func = this->format4_accel.get_glyph_func; + } + break; + } + } + + inline void fini (void) + { + hb_blob_destroy (this->blob); + } + + inline bool get_nominal_glyph (hb_codepoint_t unicode, + hb_codepoint_t *glyph) const + { + return this->get_glyph_func (this->get_glyph_data, unicode, glyph); + } + + inline bool get_variation_glyph (hb_codepoint_t unicode, + hb_codepoint_t variation_selector, + hb_codepoint_t *glyph) const + { + switch (this->uvs_table->get_glyph_variant (unicode, + variation_selector, + glyph)) + { + case OT::GLYPH_VARIANT_NOT_FOUND: return false; + case OT::GLYPH_VARIANT_FOUND: return true; + case OT::GLYPH_VARIANT_USE_DEFAULT: break; + } + + return get_nominal_glyph (unicode, glyph); + } +}; + +template <typename T> +struct hb_lazy_loader_t +{ + inline void init (hb_face_t *face_) + { + face = face_; + instance = NULL; + } + + inline void fini (void) + { + if (instance && instance != &OT::Null(T)) + { + instance->fini(); + free (instance); + } + } + + inline const T* operator-> (void) const + { + retry: + T *p = (T *) hb_atomic_ptr_get (&instance); + if (unlikely (!p)) + { + p = (T *) calloc (1, sizeof (T)); + if (unlikely (!p)) + return &OT::Null(T); + p->init (face); + if (unlikely (!hb_atomic_ptr_cmpexch (const_cast<T **>(&instance), NULL, p))) + { + p->fini (); + goto retry; + } + } + return p; + } + + private: + hb_face_t *face; + T *instance; +}; + +struct hb_ot_font_t +{ + hb_ot_face_cmap_accelerator_t cmap; + hb_ot_face_metrics_accelerator_t h_metrics; + hb_ot_face_metrics_accelerator_t v_metrics; + hb_lazy_loader_t<hb_ot_face_glyf_accelerator_t> glyf; + hb_lazy_loader_t<hb_ot_face_cbdt_accelerator_t> cbdt; +}; + + +static hb_ot_font_t * +_hb_ot_font_create (hb_face_t *face) +{ + hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t)); + + if (unlikely (!ot_font)) + return NULL; + + ot_font->cmap.init (face); + ot_font->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, HB_OT_TAG_os2); + ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, HB_TAG_NONE, + ot_font->h_metrics.ascender - ot_font->h_metrics.descender); /* TODO Can we do this lazily? */ + ot_font->glyf.init (face); + ot_font->cbdt.init (face); + + return ot_font; +} + +static void +_hb_ot_font_destroy (hb_ot_font_t *ot_font) +{ + ot_font->cmap.fini (); + ot_font->h_metrics.fini (); + ot_font->v_metrics.fini (); + ot_font->glyf.fini (); + ot_font->cbdt.fini (); + + free (ot_font); +} + + +static hb_bool_t +hb_ot_get_nominal_glyph (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t unicode, + hb_codepoint_t *glyph, + void *user_data HB_UNUSED) + +{ + const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data; + return ot_font->cmap.get_nominal_glyph (unicode, glyph); +} + +static hb_bool_t +hb_ot_get_variation_glyph (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t unicode, + hb_codepoint_t variation_selector, + hb_codepoint_t *glyph, + void *user_data HB_UNUSED) +{ + const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data; + return ot_font->cmap.get_variation_glyph (unicode, variation_selector, glyph); +} + +static hb_position_t +hb_ot_get_glyph_h_advance (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t glyph, + void *user_data HB_UNUSED) +{ + const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data; + return font->em_scale_x (ot_font->h_metrics.get_advance (glyph)); +} + +static hb_position_t +hb_ot_get_glyph_v_advance (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t glyph, + void *user_data HB_UNUSED) +{ + const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data; + return font->em_scale_y (-(int) ot_font->v_metrics.get_advance (glyph)); +} + +static hb_bool_t +hb_ot_get_glyph_extents (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t glyph, + hb_glyph_extents_t *extents, + void *user_data HB_UNUSED) +{ + const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data; + bool ret = ot_font->glyf->get_extents (glyph, extents); + if (!ret) + ret = ot_font->cbdt->get_extents (glyph, extents); + extents->x_bearing = font->em_scale_x (extents->x_bearing); + extents->y_bearing = font->em_scale_y (extents->y_bearing); + extents->width = font->em_scale_x (extents->width); + extents->height = font->em_scale_y (extents->height); + return ret; +} + +static hb_bool_t +hb_ot_get_font_h_extents (hb_font_t *font HB_UNUSED, + void *font_data, + hb_font_extents_t *metrics, + void *user_data HB_UNUSED) +{ + const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data; + metrics->ascender = font->em_scale_y (ot_font->h_metrics.ascender); + metrics->descender = font->em_scale_y (ot_font->h_metrics.descender); + metrics->line_gap = font->em_scale_y (ot_font->h_metrics.line_gap); + return ot_font->h_metrics.has_font_extents; +} + +static hb_bool_t +hb_ot_get_font_v_extents (hb_font_t *font HB_UNUSED, + void *font_data, + hb_font_extents_t *metrics, + void *user_data HB_UNUSED) +{ + const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data; + metrics->ascender = font->em_scale_x (ot_font->v_metrics.ascender); + metrics->descender = font->em_scale_x (ot_font->v_metrics.descender); + metrics->line_gap = font->em_scale_x (ot_font->v_metrics.line_gap); + return ot_font->v_metrics.has_font_extents; +} + +static hb_font_funcs_t *static_ot_funcs = NULL; + +#ifdef HB_USE_ATEXIT +static +void free_static_ot_funcs (void) +{ + hb_font_funcs_destroy (static_ot_funcs); +} +#endif + +static hb_font_funcs_t * +_hb_ot_get_font_funcs (void) +{ +retry: + hb_font_funcs_t *funcs = (hb_font_funcs_t *) hb_atomic_ptr_get (&static_ot_funcs); + + if (unlikely (!funcs)) + { + funcs = hb_font_funcs_create (); + + hb_font_funcs_set_font_h_extents_func (funcs, hb_ot_get_font_h_extents, NULL, NULL); + hb_font_funcs_set_font_v_extents_func (funcs, hb_ot_get_font_v_extents, NULL, NULL); + hb_font_funcs_set_nominal_glyph_func (funcs, hb_ot_get_nominal_glyph, NULL, NULL); + hb_font_funcs_set_variation_glyph_func (funcs, hb_ot_get_variation_glyph, NULL, NULL); + hb_font_funcs_set_glyph_h_advance_func (funcs, hb_ot_get_glyph_h_advance, NULL, NULL); + hb_font_funcs_set_glyph_v_advance_func (funcs, hb_ot_get_glyph_v_advance, NULL, NULL); + //hb_font_funcs_set_glyph_h_origin_func (funcs, hb_ot_get_glyph_h_origin, NULL, NULL); + //hb_font_funcs_set_glyph_v_origin_func (funcs, hb_ot_get_glyph_v_origin, NULL, NULL); + //hb_font_funcs_set_glyph_h_kerning_func (funcs, hb_ot_get_glyph_h_kerning, NULL, NULL); TODO + //hb_font_funcs_set_glyph_v_kerning_func (funcs, hb_ot_get_glyph_v_kerning, NULL, NULL); + hb_font_funcs_set_glyph_extents_func (funcs, hb_ot_get_glyph_extents, NULL, NULL); + //hb_font_funcs_set_glyph_contour_point_func (funcs, hb_ot_get_glyph_contour_point, NULL, NULL); TODO + //hb_font_funcs_set_glyph_name_func (funcs, hb_ot_get_glyph_name, NULL, NULL); TODO + //hb_font_funcs_set_glyph_from_name_func (funcs, hb_ot_get_glyph_from_name, NULL, NULL); TODO + + hb_font_funcs_make_immutable (funcs); + + if (!hb_atomic_ptr_cmpexch (&static_ot_funcs, NULL, funcs)) { + hb_font_funcs_destroy (funcs); + goto retry; + } + +#ifdef HB_USE_ATEXIT + atexit (free_static_ot_funcs); /* First person registers atexit() callback. */ +#endif + }; + + return funcs; +} + + +/** + * hb_ot_font_set_funcs: + * + * Since: 0.9.28 + **/ +void +hb_ot_font_set_funcs (hb_font_t *font) +{ + hb_ot_font_t *ot_font = _hb_ot_font_create (font->face); + if (unlikely (!ot_font)) + return; + + hb_font_set_funcs (font, + _hb_ot_get_font_funcs (), + ot_font, + (hb_destroy_func_t) _hb_ot_font_destroy); +} |