/*
* 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-var-hvar-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::hmtxvmtx *table;
hb_blob_t *blob;
const OT::HVARVVAR *var;
hb_blob_t *var_blob;
inline void init (hb_face_t *face,
hb_tag_t _hea_tag,
hb_tag_t _mtx_tag,
hb_tag_t _var_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::hmtxvmtx>::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::hmtxvmtx>::lock_instance (this->blob);
this->var_blob = OT::Sanitizer<OT::HVARVVAR>::sanitize (face->reference_table (_var_tag));
this->var = OT::Sanitizer<OT::HVARVVAR>::lock_instance (this->var_blob);
}
inline void fini (void)
{
hb_blob_destroy (this->blob);
hb_blob_destroy (this->var_blob);
}
inline unsigned int get_advance (hb_codepoint_t glyph,
hb_font_t *font) 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;
}
return this->table->longMetric[MIN (glyph, (uint32_t) this->num_advances - 1)].advance
+ this->var->get_advance_var (glyph, font->coords, font->num_coords); // TODO Optimize?!
}
};
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);
}
};
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;
OT::hb_lazy_loader_t<hb_ot_face_glyf_accelerator_t> glyf;
OT::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_HVAR, HB_OT_TAG_os2);
ot_font->v_metrics.init (face, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, HB_OT_TAG_VVAR, 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,
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, font));
}
static hb_position_t
hb_ot_get_glyph_v_advance (hb_font_t *font,
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, font));
}
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);
// TODO Hook up side-bearings variations.
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);
// TODO Hook up variations.
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);
// TODO Hook up variations.
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);
}