ref: 44aa7e0af52e44ccf87e62dc38dddc82af3255d7
dir: /src/autofit/hbshim.c/
/***************************************************************************/
/* */
/* hbshim.c */
/* */
/* HarfBuzz interface for accessing OpenType features (body). */
/* */
/* Copyright 2013 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#include <ft2build.h>
#include FT_FREETYPE_H
#include "hbshim.h"
#ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
/*************************************************************************/
/* */
/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
/* messages during execution. */
/* */
#undef FT_COMPONENT
#define FT_COMPONENT trace_afharfbuzz
/*
* We use `sets' (in the HarfBuzz sense, which comes quite near to the
* usual mathematical meaning) to manage both lookups and glyph indices.
*
* 1. For each coverage, collect lookup IDs in a set. Note that an
* auto-hinter `coverage' is represented by one `feature', and a
* feature consists of an arbitrary number of (font specific) `lookup's
* that actually do the mapping job. Please check the OpenType
* specification for more details on features and lookups.
*
* 2. Create glyph ID sets from the corresponding lookup sets.
*
* 3. The glyph set corresponding to AF_COVERAGE_DEFAULT is computed
* with all lookups specific to the OpenType script activated. It
* relies on the order of AF_DEFINE_STYLE_CLASS entries so that
* special coverages (like `oldstyle figures') don't get overwritten.
*
*/
/* load coverage tags */
#undef COVERAGE
#define COVERAGE( name, NAME, description, \
tag1, tag2, tag3, tag4 ) \
static const hb_tag_t name ## _coverage[] = \
{ \
HB_TAG( tag1, tag2, tag3, tag4 ), \
HB_TAG_NONE \
};
#include "afcover.h"
/* define mapping between coverage tags and AF_Coverage */
#undef COVERAGE
#define COVERAGE( name, NAME, description, \
tag1, tag2, tag3, tag4 ) \
name ## _coverage,
static const hb_tag_t* coverages[] =
{
#include "afcover.h"
NULL /* AF_COVERAGE_DEFAULT */
};
/* load HarfBuzz script tags */
#undef SCRIPT
#define SCRIPT( s, S, d, h, dc ) h,
static const hb_tag_t scripts[] =
{
#include "afscript.h"
};
FT_Error
af_get_coverage( AF_FaceGlobals globals,
AF_StyleClass style_class,
FT_Byte* gstyles )
{
hb_face_t* face;
hb_set_t* lookups; /* lookups for a given script */
hb_set_t* glyphs; /* glyphs covered by lookups */
hb_tag_t script;
const hb_tag_t* coverage_tags;
hb_tag_t script_tags[] = { HB_TAG_NONE,
HB_TAG_NONE,
HB_TAG_NONE,
HB_TAG_NONE };
hb_codepoint_t idx;
#ifdef FT_DEBUG_LEVEL_TRACE
int count;
#endif
if ( !globals || !style_class || !gstyles )
return FT_THROW( Invalid_Argument );
face = hb_font_get_face( globals->hb_font );
lookups = hb_set_create();
glyphs = hb_set_create();
coverage_tags = coverages[style_class->coverage];
script = scripts[style_class->script];
/* Convert a HarfBuzz script tag into the corresponding OpenType */
/* tag or tags -- some Indic scripts like Devanagari have an old */
/* and a new set of features. */
hb_ot_tags_from_script( script,
&script_tags[0],
&script_tags[1] );
/* `hb_ot_tags_from_script' usually returns HB_OT_TAG_DEFAULT_SCRIPT */
/* as the second tag. We change that to HB_TAG_NONE except for the */
/* default script. */
if ( style_class->script == globals->module->default_script &&
style_class->coverage == AF_COVERAGE_DEFAULT )
{
if ( script_tags[0] == HB_TAG_NONE )
script_tags[0] = HB_OT_TAG_DEFAULT_SCRIPT;
else
{
if ( script_tags[1] == HB_TAG_NONE )
script_tags[1] = HB_OT_TAG_DEFAULT_SCRIPT;
else if ( script_tags[1] != HB_OT_TAG_DEFAULT_SCRIPT )
script_tags[2] = HB_OT_TAG_DEFAULT_SCRIPT;
}
}
else
{
if ( script_tags[1] == HB_OT_TAG_DEFAULT_SCRIPT )
script_tags[1] = HB_TAG_NONE;
}
hb_ot_layout_collect_lookups( face,
HB_OT_TAG_GSUB,
script_tags,
NULL,
coverage_tags,
lookups );
FT_TRACE4(( "lookups (style `%s'):\n"
" ",
af_style_names[style_class->style] ));
#ifdef FT_DEBUG_LEVEL_TRACE
count = 0;
#endif
for ( idx = -1; hb_set_next( lookups, &idx ); )
{
#ifdef FT_DEBUG_LEVEL_TRACE
FT_TRACE4(( " %d", idx ));
count++;
#endif
hb_ot_layout_lookup_collect_glyphs( face,
HB_OT_TAG_GSUB,
idx,
NULL,
NULL,
NULL,
glyphs );
}
#ifdef FT_DEBUG_LEVEL_TRACE
if ( !count )
FT_TRACE4(( " (none)" ));
FT_TRACE4(( "\n\n" ));
FT_TRACE4(( " glyphs (`*' means already assigned)" ));
count = 0;
#endif
for ( idx = -1; hb_set_next( glyphs, &idx ); )
{
#ifdef FT_DEBUG_LEVEL_TRACE
if ( !( count % 10 ) )
FT_TRACE4(( "\n"
" " ));
FT_TRACE4(( " %d", idx ));
count++;
#endif
if ( gstyles[idx] == AF_STYLE_UNASSIGNED )
gstyles[idx] = (FT_Byte)style_class->style;
#ifdef FT_DEBUG_LEVEL_TRACE
else
FT_TRACE4(( "*" ));
#endif
}
#ifdef FT_DEBUG_LEVEL_TRACE
if ( !count )
FT_TRACE4(( "\n"
" (none)" ));
FT_TRACE4(( "\n\n" ));
#endif
hb_set_destroy( lookups );
hb_set_destroy( glyphs );
return FT_Err_Ok;
}
FT_UInt
af_get_char_index( AF_StyleMetrics metrics,
FT_ULong charcode )
{
FT_Face face;
if ( !metrics )
return FT_THROW( Invalid_Argument );
face = metrics->globals->face;
return FT_Get_Char_Index( face, charcode );
}
#else /* !FT_CONFIG_OPTION_USE_HARDBUZZ */
FT_Error
af_get_coverage( AF_FaceGlobals globals,
AF_StyleClass style_class,
FT_Byte* gstyles )
{
FT_UNUSED( globals );
FT_UNUSED( style_class );
FT_UNUSED( gstyles );
return FT_Err_Ok;
}
FT_UInt
af_get_char_index( AF_StyleMetrics metrics,
FT_ULong charcode )
{
FT_Face face;
if ( !metrics )
return FT_THROW( Invalid_Argument );
face = metrics->globals->face;
return FT_Get_Char_Index( face, charcode );
}
#endif /* !FT_CONFIG_OPTION_USE_HARFBUZZ */
/* END */