harfbuzz/src/hb-ot-layout.cc

645 lines
19 KiB
C++

/*
* Copyright (C) 1998-2004 David Turner and Werner Lemberg
* Copyright (C) 2006 Behdad Esfahbod
* Copyright (C) 2007,2008,2009 Red Hat, Inc.
*
* This is part of HarfBuzz, an OpenType Layout engine 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.
*
* Red Hat Author(s): Behdad Esfahbod
*/
#define HB_OT_LAYOUT_CC
#include "hb-ot-layout-private.h"
#include "hb-ot-layout-gdef-private.hh"
#include "hb-ot-layout-gsub-private.hh"
#include "hb-ot-layout-gpos-private.hh"
#include <stdlib.h>
#include <string.h>
void
_hb_ot_layout_init (hb_face_t *face)
{
hb_ot_layout_t *layout = &face->ot_layout;
layout->gdef_blob = Sanitizer<GDEF>::sanitize (hb_face_get_table (face, HB_OT_TAG_GDEF));
layout->gdef = &Sanitizer<GDEF>::lock_instance (layout->gdef_blob);
layout->gsub_blob = Sanitizer<GSUB>::sanitize (hb_face_get_table (face, HB_OT_TAG_GSUB));
layout->gsub = &Sanitizer<GSUB>::lock_instance (layout->gsub_blob);
layout->gpos_blob = Sanitizer<GPOS>::sanitize (hb_face_get_table (face, HB_OT_TAG_GPOS));
layout->gpos = &Sanitizer<GPOS>::lock_instance (layout->gpos_blob);
}
void
_hb_ot_layout_fini (hb_face_t *face)
{
hb_ot_layout_t *layout = &face->ot_layout;
hb_blob_unlock (layout->gdef_blob);
hb_blob_unlock (layout->gsub_blob);
hb_blob_unlock (layout->gpos_blob);
hb_blob_destroy (layout->gdef_blob);
hb_blob_destroy (layout->gsub_blob);
hb_blob_destroy (layout->gpos_blob);
free (layout->new_gdef.klasses);
}
static const GDEF&
_get_gdef (hb_face_t *face)
{
return HB_LIKELY (face->ot_layout.gdef) ? *face->ot_layout.gdef : Null(GDEF);
}
static const GSUB&
_get_gsub (hb_face_t *face)
{
return HB_LIKELY (face->ot_layout.gsub) ? *face->ot_layout.gsub : Null(GSUB);
}
static const GPOS&
_get_gpos (hb_face_t *face)
{
return HB_LIKELY (face->ot_layout.gpos) ? *face->ot_layout.gpos : Null(GPOS);
}
/*
* GDEF
*/
/* TODO the public class_t is a mess */
hb_bool_t
hb_ot_layout_has_glyph_classes (hb_face_t *face)
{
return _get_gdef (face).has_glyph_classes ();
}
hb_bool_t
_hb_ot_layout_has_new_glyph_classes (hb_face_t *face)
{
return face->ot_layout.new_gdef.len > 0;
}
static unsigned int
_hb_ot_layout_get_glyph_property (hb_face_t *face,
hb_codepoint_t glyph)
{
hb_ot_layout_class_t klass;
const GDEF &gdef = _get_gdef (face);
klass = gdef.get_glyph_class (glyph);
if (!klass && glyph < face->ot_layout.new_gdef.len)
klass = face->ot_layout.new_gdef.klasses[glyph];
switch (klass) {
default:
case GDEF::UnclassifiedGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED;
case GDEF::BaseGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
case GDEF::LigatureGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE;
case GDEF::ComponentGlyph: return HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT;
case GDEF::MarkGlyph:
klass = gdef.get_mark_attachment_type (glyph);
return HB_OT_LAYOUT_GLYPH_CLASS_MARK + (klass << 8);
}
}
hb_bool_t
_hb_ot_layout_check_glyph_property (hb_face_t *face,
hb_internal_glyph_info_t *ginfo,
unsigned int lookup_flags,
unsigned int *property_out)
{
unsigned int property;
if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
ginfo->gproperty = _hb_ot_layout_get_glyph_property (face, ginfo->codepoint);
property = ginfo->gproperty;
if (property_out)
*property_out = property;
/* Not covered, if, for example, glyph class is ligature and
* lookup_flags includes LookupFlags::IgnoreLigatures
*/
if (property & lookup_flags & LookupFlag::IgnoreFlags)
return false;
if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
{
/* If using mark filtering sets, the high short of
* lookup_flags has the set index.
*/
if (lookup_flags & LookupFlag::UseMarkFilteringSet)
return _get_gdef (face).mark_set_covers (lookup_flags >> 16, ginfo->codepoint);
/* The second byte of lookup_flags has the meaning
* "ignore marks of attachment type different than
* the attachment type specified."
*/
if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType)
return (lookup_flags & LookupFlag::MarkAttachmentType) == (property & LookupFlag::MarkAttachmentType);
}
return true;
}
hb_bool_t
_hb_ot_layout_skip_mark (hb_face_t *face,
hb_internal_glyph_info_t *ginfo,
unsigned int lookup_flags,
unsigned int *property_out)
{
unsigned int property;
if (ginfo->gproperty == HB_BUFFER_GLYPH_PROPERTIES_UNKNOWN)
ginfo->gproperty = _hb_ot_layout_get_glyph_property (face, ginfo->codepoint);
property = ginfo->gproperty;
if (property_out)
*property_out = property;
if (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
{
/* Skip mark if lookup_flags includes LookupFlags::IgnoreMarks */
if (lookup_flags & LookupFlag::IgnoreMarks)
return true;
/* If using mark filtering sets, the high short of lookup_flags has the set index. */
if (lookup_flags & LookupFlag::UseMarkFilteringSet)
return !_get_gdef (face).mark_set_covers (lookup_flags >> 16, ginfo->codepoint);
/* The second byte of lookup_flags has the meaning "ignore marks of attachment type
* different than the attachment type specified." */
if (lookup_flags & LookupFlag::MarkAttachmentType && property & LookupFlag::MarkAttachmentType)
return (lookup_flags & LookupFlag::MarkAttachmentType) != (property & LookupFlag::MarkAttachmentType);
}
return false;
}
void
_hb_ot_layout_set_glyph_class (hb_face_t *face,
hb_codepoint_t glyph,
hb_ot_layout_glyph_class_t klass)
{
if (HB_OBJECT_IS_INERT (face))
return;
/* TODO optimize this? similar to old harfbuzz code for example */
hb_ot_layout_t *layout = &face->ot_layout;
hb_ot_layout_class_t gdef_klass;
unsigned int len = layout->new_gdef.len;
if (HB_UNLIKELY (glyph > 65535))
return;
/* XXX this is not threadsafe */
if (glyph >= len) {
unsigned int new_len;
unsigned char *new_klasses;
new_len = len == 0 ? 120 : 2 * len;
while (new_len <= glyph)
new_len *= 2;
if (new_len > 65536)
new_len = 65536;
new_klasses = (unsigned char *) realloc (layout->new_gdef.klasses, new_len * sizeof (unsigned char));
if (HB_UNLIKELY (!new_klasses))
return;
memset (new_klasses + len, 0, new_len - len);
layout->new_gdef.klasses = new_klasses;
layout->new_gdef.len = new_len;
}
switch (klass) {
default:
case HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED: gdef_klass = GDEF::UnclassifiedGlyph; break;
case HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH: gdef_klass = GDEF::BaseGlyph; break;
case HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE: gdef_klass = GDEF::LigatureGlyph; break;
case HB_OT_LAYOUT_GLYPH_CLASS_MARK: gdef_klass = GDEF::MarkGlyph; break;
case HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT: gdef_klass = GDEF::ComponentGlyph; break;
}
layout->new_gdef.klasses[glyph] = gdef_klass;
return;
}
void
_hb_ot_layout_set_glyph_property (hb_face_t *face,
hb_codepoint_t glyph,
unsigned int property)
{ _hb_ot_layout_set_glyph_class (face, glyph, (hb_ot_layout_glyph_class_t) (property & 0xff)); }
hb_ot_layout_glyph_class_t
hb_ot_layout_get_glyph_class (hb_face_t *face,
hb_codepoint_t glyph)
{
return (hb_ot_layout_glyph_class_t) (_hb_ot_layout_get_glyph_property (face, glyph) & 0xff);
}
void
hb_ot_layout_set_glyph_class (hb_face_t *face,
hb_codepoint_t glyph,
hb_ot_layout_glyph_class_t klass)
{
_hb_ot_layout_set_glyph_class (face, glyph, klass);
}
void
hb_ot_layout_build_glyph_classes (hb_face_t *face,
uint16_t num_total_glyphs,
hb_codepoint_t *glyphs,
unsigned char *klasses,
uint16_t count)
{
if (HB_OBJECT_IS_INERT (face))
return;
hb_ot_layout_t *layout = &face->ot_layout;
if (HB_UNLIKELY (!count || !glyphs || !klasses))
return;
if (layout->new_gdef.len == 0) {
layout->new_gdef.klasses = (unsigned char *) calloc (num_total_glyphs, sizeof (unsigned char));
layout->new_gdef.len = count;
}
for (unsigned int i = 0; i < count; i++)
_hb_ot_layout_set_glyph_class (face, glyphs[i], (hb_ot_layout_glyph_class_t) klasses[i]);
}
unsigned int
hb_ot_layout_get_attach_points (hb_face_t *face,
hb_codepoint_t glyph,
unsigned int start_offset,
unsigned int *point_count /* IN/OUT */,
unsigned int *point_array /* OUT */)
{
return _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);
}
unsigned int
hb_ot_layout_get_lig_carets (hb_font_t *font,
hb_face_t *face,
hb_codepoint_t glyph,
unsigned int start_offset,
unsigned int *caret_count /* IN/OUT */,
int *caret_array /* OUT */)
{
hb_ot_layout_context_t context;
context.font = font;
context.face = face;
return _get_gdef (face).get_lig_carets (&context, glyph, start_offset, caret_count, caret_array);
}
/*
* GSUB/GPOS
*/
static const GSUBGPOS&
get_gsubgpos_table (hb_face_t *face,
hb_tag_t table_tag)
{
switch (table_tag) {
case HB_OT_TAG_GSUB: return _get_gsub (face);
case HB_OT_TAG_GPOS: return _get_gpos (face);
default: return Null(GSUBGPOS);
}
}
unsigned int
hb_ot_layout_table_get_script_tags (hb_face_t *face,
hb_tag_t table_tag,
unsigned int start_offset,
unsigned int *script_count /* IN/OUT */,
hb_tag_t *script_tags /* OUT */)
{
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
return g.get_script_tags (start_offset, script_count, script_tags);
}
hb_bool_t
hb_ot_layout_table_find_script (hb_face_t *face,
hb_tag_t table_tag,
hb_tag_t script_tag,
unsigned int *script_index)
{
ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
if (g.find_script_index (script_tag, script_index))
return TRUE;
/* try finding 'DFLT' */
if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
return FALSE;
/* try with 'dflt'; MS site has had typos and many fonts use it now :( */
if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
return FALSE;
if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
return FALSE;
}
hb_bool_t
hb_ot_layout_table_choose_script (hb_face_t *face,
hb_tag_t table_tag,
const hb_tag_t *script_tags,
unsigned int *script_index)
{
ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
while (*script_tags)
{
if (g.find_script_index (*script_tags, script_index))
return TRUE;
script_tags++;
}
/* try finding 'DFLT' */
if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
return FALSE;
/* try with 'dflt'; MS site has had typos and many fonts use it now :( */
if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
return FALSE;
if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
return FALSE;
}
unsigned int
hb_ot_layout_table_get_feature_tags (hb_face_t *face,
hb_tag_t table_tag,
unsigned int start_offset,
unsigned int *feature_count /* IN/OUT */,
hb_tag_t *feature_tags /* OUT */)
{
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
return g.get_feature_tags (start_offset, feature_count, feature_tags);
}
unsigned int
hb_ot_layout_script_get_language_tags (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int start_offset,
unsigned int *language_count /* IN/OUT */,
hb_tag_t *language_tags /* OUT */)
{
const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
return s.get_lang_sys_tags (start_offset, language_count, language_tags);
}
hb_bool_t
hb_ot_layout_script_find_language (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
hb_tag_t language_tag,
unsigned int *language_index)
{
ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
if (s.find_lang_sys_index (language_tag, language_index))
return TRUE;
/* try with 'dflt'; MS site has had typos and many fonts use it now :( */
if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
return FALSE;
if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
return FALSE;
}
hb_bool_t
hb_ot_layout_language_get_required_feature_index (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
unsigned int *feature_index)
{
const LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index);
if (feature_index) *feature_index = l.get_required_feature_index ();
return l.has_required_feature ();
}
unsigned int
hb_ot_layout_language_get_feature_indexes (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
unsigned int start_offset,
unsigned int *feature_count /* IN/OUT */,
unsigned int *feature_indexes /* OUT */)
{
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
}
unsigned int
hb_ot_layout_language_get_feature_tags (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
unsigned int start_offset,
unsigned int *feature_count /* IN/OUT */,
hb_tag_t *feature_tags /* OUT */)
{
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
ASSERT_STATIC (sizeof (unsigned int) == sizeof (hb_tag_t));
unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
if (feature_tags) {
unsigned int count = *feature_count;
for (unsigned int i = 0; i < count; i++)
feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
}
return ret;
}
hb_bool_t
hb_ot_layout_language_find_feature (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
hb_tag_t feature_tag,
unsigned int *feature_index)
{
ASSERT_STATIC (NO_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
unsigned int num_features = l.get_feature_count ();
for (unsigned int i = 0; i < num_features; i++) {
unsigned int f_index = l.get_feature_index (i);
if (feature_tag == g.get_feature_tag (f_index)) {
if (feature_index) *feature_index = f_index;
return TRUE;
}
}
if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
return FALSE;
}
unsigned int
hb_ot_layout_feature_get_lookup_indexes (hb_face_t *face,
hb_tag_t table_tag,
unsigned int feature_index,
unsigned int start_offset,
unsigned int *lookup_count /* IN/OUT */,
unsigned int *lookup_indexes /* OUT */)
{
const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
const Feature &f = g.get_feature (feature_index);
return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
}
/*
* GSUB
*/
hb_bool_t
hb_ot_layout_has_substitution (hb_face_t *face)
{
return &_get_gsub (face) != &Null(GSUB);
}
hb_bool_t
hb_ot_layout_substitute_lookup (hb_face_t *face,
hb_buffer_t *buffer,
unsigned int lookup_index,
hb_mask_t mask)
{
hb_ot_layout_context_t context;
context.font = NULL;
context.face = face;
return _get_gsub (face).substitute_lookup (&context, buffer, lookup_index, mask);
}
/*
* GPOS
*/
hb_bool_t
hb_ot_layout_has_positioning (hb_face_t *face)
{
return &_get_gpos (face) != &Null(GPOS);
}
hb_bool_t
hb_ot_layout_position_lookup (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
unsigned int lookup_index,
hb_mask_t mask)
{
hb_ot_layout_context_t context;
context.font = font;
context.face = face;
return _get_gpos (face).position_lookup (&context, buffer, lookup_index, mask);
}
void
hb_ot_layout_position_finish (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer)
{
unsigned int i, j;
unsigned int len = hb_buffer_get_length (buffer);
hb_internal_glyph_position_t *positions = (hb_internal_glyph_position_t *) hb_buffer_get_glyph_positions (buffer);
/* TODO: Vertical */
/* Handle cursive connections */
/* First handle all left-to-right connections */
for (j = 0; j < len; j++) {
if (positions[j].cursive_chain > 0) {
positions[j].y_offset += positions[j - positions[j].cursive_chain].y_offset;
positions[j].cursive_chain = 0;
}
}
/* Then handle all right-to-left connections */
for (i = len; i > 0; i--) {
j = i - 1;
if (positions[j].cursive_chain < 0) {
positions[j].y_offset += positions[j - positions[j].cursive_chain].y_offset;
positions[j].cursive_chain = 0;
}
}
/* Handle attachments */
for (i = 0; i < len; i++)
if (positions[i].back)
{
unsigned int back = i - positions[i].back;
positions[i].back = 0;
positions[i].x_offset += positions[back].x_offset;
positions[i].y_offset += positions[back].y_offset;
if (buffer->direction == HB_DIRECTION_RTL)
for (j = back + 1; j < i + 1; j++) {
positions[i].x_offset += positions[j].x_advance;
positions[i].y_offset += positions[j].y_advance;
}
else
for (j = back; j < i; j++) {
positions[i].x_offset -= positions[j].x_advance;
positions[i].y_offset -= positions[j].y_advance;
}
}
}