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Diffstat (limited to 'src/hb-ot-font.cc')
-rw-r--r-- | src/hb-ot-font.cc | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc new file mode 100644 index 0000000..2af2f54 --- /dev/null +++ b/src/hb-ot-font.cc @@ -0,0 +1,348 @@ +/* + * 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-hhea-table.hh" +#include "hb-ot-hmtx-table.hh" + + +struct hb_ot_face_metrics_accelerator_t +{ + unsigned int num_metrics; + unsigned int num_advances; + unsigned int default_advance; + 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, + unsigned int default_advance) + { + this->default_advance = default_advance; + this->num_metrics = face->get_num_glyphs (); + + 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; + hb_blob_destroy (_hea_blob); + + this->blob = OT::Sanitizer<OT::_mtx>::sanitize (face->reference_table (_mtx_tag)); + if (unlikely (!this->num_advances || + 2 * (this->num_advances + this->num_metrics) < hb_blob_get_length (this->blob))) + { + 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 one EM. 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_cmap_accelerator_t +{ + const OT::CmapSubtable *table; + const OT::CmapSubtable *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::CmapSubtable *subtable_uvs = NULL; + + /* 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); + /* Meh. */ + if (!subtable) subtable = &OT::Null(OT::CmapSubtable); + + /* UVS subtable. */ + if (!subtable_uvs) subtable_uvs = cmap->find_subtable (0, 5); + /* Meh. */ + if (!subtable_uvs) subtable_uvs = &OT::Null(OT::CmapSubtable); + + this->table = subtable; + this->uvs_table = subtable_uvs; + } + + inline void fini (void) + { + hb_blob_destroy (this->blob); + } + + inline bool get_glyph (hb_codepoint_t unicode, + hb_codepoint_t variation_selector, + hb_codepoint_t *glyph) const + { + if (unlikely (variation_selector)) + { + 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 this->table->get_glyph (unicode, glyph); + } +}; + + +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; +}; + + +static hb_ot_font_t * +_hb_ot_font_create (hb_font_t *font) +{ + hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t)); + hb_face_t *face = font->face; + + if (unlikely (!ot_font)) + return NULL; + + unsigned int upem = face->get_upem (); + + ot_font->cmap.init (face); + ot_font->h_metrics.init (face, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, upem>>1); + ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, upem); /* TODO Can we do this lazily? */ + + 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 (); + + free (ot_font); +} + + +static hb_bool_t +hb_ot_get_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_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 (-ot_font->v_metrics.get_advance (glyph)); +} + +static hb_bool_t +hb_ot_get_glyph_h_origin (hb_font_t *font HB_UNUSED, + void *font_data HB_UNUSED, + hb_codepoint_t glyph HB_UNUSED, + hb_position_t *x HB_UNUSED, + hb_position_t *y HB_UNUSED, + void *user_data HB_UNUSED) +{ + /* We always work in the horizontal coordinates. */ + return true; +} + +static hb_bool_t +hb_ot_get_glyph_v_origin (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t glyph, + hb_position_t *x, + hb_position_t *y, + void *user_data HB_UNUSED) +{ + /* TODO */ + return false; +} + +static hb_position_t +hb_ot_get_glyph_h_kerning (hb_font_t *font, + void *font_data, + hb_codepoint_t left_glyph, + hb_codepoint_t right_glyph, + void *user_data HB_UNUSED) +{ + /* TODO */ + return 0; +} + +static hb_position_t +hb_ot_get_glyph_v_kerning (hb_font_t *font HB_UNUSED, + void *font_data HB_UNUSED, + hb_codepoint_t top_glyph HB_UNUSED, + hb_codepoint_t bottom_glyph HB_UNUSED, + void *user_data HB_UNUSED) +{ + /* OpenType doesn't have vertical-kerning other than GPOS. */ + return 0; +} + +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) +{ + /* TODO */ + return false; +} + +static hb_bool_t +hb_ot_get_glyph_contour_point (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t glyph, + unsigned int point_index, + hb_position_t *x, + hb_position_t *y, + void *user_data HB_UNUSED) +{ + /* TODO */ + return false; +} + +static hb_bool_t +hb_ot_get_glyph_name (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t glyph, + char *name, unsigned int size, + void *user_data HB_UNUSED) +{ + /* TODO */ + return false; +} + +static hb_bool_t +hb_ot_get_glyph_from_name (hb_font_t *font HB_UNUSED, + void *font_data, + const char *name, int len, /* -1 means nul-terminated */ + hb_codepoint_t *glyph, + void *user_data HB_UNUSED) +{ + /* TODO */ + return false; +} + + +static hb_font_funcs_t * +_hb_ot_get_font_funcs (void) +{ + static const hb_font_funcs_t ot_ffuncs = { + HB_OBJECT_HEADER_STATIC, + + true, /* immutable */ + + { +#define HB_FONT_FUNC_IMPLEMENT(name) hb_ot_get_##name, + HB_FONT_FUNCS_IMPLEMENT_CALLBACKS +#undef HB_FONT_FUNC_IMPLEMENT + } + }; + + return const_cast<hb_font_funcs_t *> (&ot_ffuncs); +} + + +void +hb_ot_font_set_funcs (hb_font_t *font) +{ + hb_ot_font_t *ot_font = _hb_ot_font_create (font); + 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); +} |