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Diffstat (limited to 'src/autofit/afshaper.c')
| -rw-r--r-- | src/autofit/afshaper.c | 683 |
1 files changed, 0 insertions, 683 deletions
diff --git a/src/autofit/afshaper.c b/src/autofit/afshaper.c deleted file mode 100644 index da92fad3e..000000000 --- a/src/autofit/afshaper.c +++ /dev/null @@ -1,683 +0,0 @@ -/***************************************************************************/ -/* */ -/* afshaper.c */ -/* */ -/* HarfBuzz interface for accessing OpenType features (body). */ -/* */ -/* Copyright 2013-2017 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 "afglobal.h" -#include "aftypes.h" -#include "afshaper.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_afshaper - - - /* - * 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, H, ss ) h, - - - static const hb_script_t scripts[] = - { -#include "afscript.h" - }; - - - FT_Error - af_shaper_get_coverage( AF_FaceGlobals globals, - AF_StyleClass style_class, - FT_UShort* gstyles, - FT_Bool default_script ) - { - hb_face_t* face; - - hb_set_t* gsub_lookups; /* GSUB lookups for a given script */ - hb_set_t* gsub_glyphs; /* glyphs covered by GSUB lookups */ - hb_set_t* gpos_lookups; /* GPOS lookups for a given script */ - hb_set_t* gpos_glyphs; /* glyphs covered by GPOS lookups */ - - hb_script_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 ); - - gsub_lookups = hb_set_create(); - gsub_glyphs = hb_set_create(); - gpos_lookups = hb_set_create(); - gpos_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 ( default_script ) - { - 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 - { - /* we use non-standard tags like `khms' for special purposes; */ - /* HarfBuzz maps them to `DFLT', which we don't want to handle here */ - if ( script_tags[0] == HB_OT_TAG_DEFAULT_SCRIPT ) - goto Exit; - - 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, - gsub_lookups ); - - if ( hb_set_is_empty( gsub_lookups ) ) - goto Exit; /* nothing to do */ - - hb_ot_layout_collect_lookups( face, - HB_OT_TAG_GPOS, - script_tags, - NULL, - coverage_tags, - gpos_lookups ); - - FT_TRACE4(( "GSUB lookups (style `%s'):\n" - " ", - af_style_names[style_class->style] )); - -#ifdef FT_DEBUG_LEVEL_TRACE - count = 0; -#endif - - for ( idx = HB_SET_VALUE_INVALID; hb_set_next( gsub_lookups, &idx ); ) - { -#ifdef FT_DEBUG_LEVEL_TRACE - FT_TRACE4(( " %d", idx )); - count++; -#endif - - /* get output coverage of GSUB feature */ - hb_ot_layout_lookup_collect_glyphs( face, - HB_OT_TAG_GSUB, - idx, - NULL, - NULL, - NULL, - gsub_glyphs ); - } - -#ifdef FT_DEBUG_LEVEL_TRACE - if ( !count ) - FT_TRACE4(( " (none)" )); - FT_TRACE4(( "\n\n" )); -#endif - - FT_TRACE4(( "GPOS lookups (style `%s'):\n" - " ", - af_style_names[style_class->style] )); - -#ifdef FT_DEBUG_LEVEL_TRACE - count = 0; -#endif - - for ( idx = HB_SET_VALUE_INVALID; hb_set_next( gpos_lookups, &idx ); ) - { -#ifdef FT_DEBUG_LEVEL_TRACE - FT_TRACE4(( " %d", idx )); - count++; -#endif - - /* get input coverage of GPOS feature */ - hb_ot_layout_lookup_collect_glyphs( face, - HB_OT_TAG_GPOS, - idx, - NULL, - gpos_glyphs, - NULL, - NULL ); - } - -#ifdef FT_DEBUG_LEVEL_TRACE - if ( !count ) - FT_TRACE4(( " (none)" )); - FT_TRACE4(( "\n\n" )); -#endif - - /* - * We now check whether we can construct blue zones, using glyphs - * covered by the feature only. In case there is not a single zone - * (this is, not a single character is covered), we skip this coverage. - * - */ - if ( style_class->coverage != AF_COVERAGE_DEFAULT ) - { - AF_Blue_Stringset bss = style_class->blue_stringset; - const AF_Blue_StringRec* bs = &af_blue_stringsets[bss]; - - FT_Bool found = 0; - - - for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ ) - { - const char* p = &af_blue_strings[bs->string]; - - - while ( *p ) - { - hb_codepoint_t ch; - - - GET_UTF8_CHAR( ch, p ); - - for ( idx = HB_SET_VALUE_INVALID; hb_set_next( gsub_lookups, - &idx ); ) - { - hb_codepoint_t gidx = FT_Get_Char_Index( globals->face, ch ); - - - if ( hb_ot_layout_lookup_would_substitute( face, idx, - &gidx, 1, 1 ) ) - { - found = 1; - break; - } - } - } - } - - if ( !found ) - { - FT_TRACE4(( " no blue characters found; style skipped\n" )); - goto Exit; - } - } - - /* - * Various OpenType features might use the same glyphs at different - * vertical positions; for example, superscript and subscript glyphs - * could be the same. However, the auto-hinter is completely - * agnostic of OpenType features after the feature analysis has been - * completed: The engine then simply receives a glyph index and returns a - * hinted and usually rendered glyph. - * - * Consider the superscript feature of font `pala.ttf': Some of the - * glyphs are `real', this is, they have a zero vertical offset, but - * most of them are small caps glyphs shifted up to the superscript - * position (this is, the `sups' feature is present in both the GSUB and - * GPOS tables). The code for blue zones computation actually uses a - * feature's y offset so that the `real' glyphs get correct hints. But - * later on it is impossible to decide whether a glyph index belongs to, - * say, the small caps or superscript feature. - * - * For this reason, we don't assign a style to a glyph if the current - * feature covers the glyph in both the GSUB and the GPOS tables. This - * is quite a broad condition, assuming that - * - * (a) glyphs that get used in multiple features are present in a - * feature without vertical shift, - * - * and - * - * (b) a feature's GPOS data really moves the glyph vertically. - * - * Not fulfilling condition (a) makes a font larger; it would also - * reduce the number of glyphs that could be addressed directly without - * using OpenType features, so this assumption is rather strong. - * - * Condition (b) is much weaker, and there might be glyphs which get - * missed. However, the OpenType features we are going to handle are - * primarily located in GSUB, and HarfBuzz doesn't provide an API to - * directly get the necessary information from the GPOS table. A - * possible solution might be to directly parse the GPOS table to find - * out whether a glyph gets shifted vertically, but this is something I - * would like to avoid if not really necessary. - * - * Note that we don't follow this logic for the default coverage. - * Complex scripts like Devanagari have mandatory GPOS features to - * position many glyph elements, using mark-to-base or mark-to-ligature - * tables; the number of glyphs missed due to condition (b) would be far - * too large. - * - */ - if ( style_class->coverage != AF_COVERAGE_DEFAULT ) - hb_set_subtract( gsub_glyphs, gpos_glyphs ); - -#ifdef FT_DEBUG_LEVEL_TRACE - FT_TRACE4(( " glyphs without GPOS data (`*' means already assigned)" )); - count = 0; -#endif - - for ( idx = HB_SET_VALUE_INVALID; hb_set_next( gsub_glyphs, &idx ); ) - { -#ifdef FT_DEBUG_LEVEL_TRACE - if ( !( count % 10 ) ) - FT_TRACE4(( "\n" - " " )); - - FT_TRACE4(( " %d", idx )); - count++; -#endif - - /* glyph indices returned by `hb_ot_layout_lookup_collect_glyphs' */ - /* can be arbitrary: some fonts use fake indices for processing */ - /* internal to GSUB or GPOS, which is fully valid */ - if ( idx >= (hb_codepoint_t)globals->glyph_count ) - continue; - - if ( gstyles[idx] == AF_STYLE_UNASSIGNED ) - gstyles[idx] = (FT_UShort)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 - - Exit: - hb_set_destroy( gsub_lookups ); - hb_set_destroy( gsub_glyphs ); - hb_set_destroy( gpos_lookups ); - hb_set_destroy( gpos_glyphs ); - - return FT_Err_Ok; - } - - - /* construct HarfBuzz features */ -#undef COVERAGE -#define COVERAGE( name, NAME, description, \ - tag1, tag2, tag3, tag4 ) \ - static const hb_feature_t name ## _feature[] = \ - { \ - { \ - HB_TAG( tag1, tag2, tag3, tag4 ), \ - 1, 0, (unsigned int)-1 \ - } \ - }; - - -#include "afcover.h" - - - /* define mapping between HarfBuzz features and AF_Coverage */ -#undef COVERAGE -#define COVERAGE( name, NAME, description, \ - tag1, tag2, tag3, tag4 ) \ - name ## _feature, - - - static const hb_feature_t* features[] = - { -#include "afcover.h" - - NULL /* AF_COVERAGE_DEFAULT */ - }; - - - void* - af_shaper_buf_create( FT_Face face ) - { - FT_UNUSED( face ); - - return (void*)hb_buffer_create(); - } - - - void - af_shaper_buf_destroy( FT_Face face, - void* buf ) - { - FT_UNUSED( face ); - - hb_buffer_destroy( (hb_buffer_t*)buf ); - } - - - const char* - af_shaper_get_cluster( const char* p, - AF_StyleMetrics metrics, - void* buf_, - unsigned int* count ) - { - AF_StyleClass style_class; - const hb_feature_t* feature; - FT_Int upem; - const char* q; - int len; - - hb_buffer_t* buf = (hb_buffer_t*)buf_; - hb_font_t* font; - hb_codepoint_t dummy; - - - upem = (FT_Int)metrics->globals->face->units_per_EM; - style_class = metrics->style_class; - feature = features[style_class->coverage]; - - font = metrics->globals->hb_font; - - /* we shape at a size of units per EM; this means font units */ - hb_font_set_scale( font, upem, upem ); - - while ( *p == ' ' ) - p++; - - /* count bytes up to next space (or end of buffer) */ - q = p; - while ( !( *q == ' ' || *q == '\0' ) ) - GET_UTF8_CHAR( dummy, q ); - len = (int)( q - p ); - - /* feed character(s) to the HarfBuzz buffer */ - hb_buffer_clear_contents( buf ); - hb_buffer_add_utf8( buf, p, len, 0, len ); - - /* we let HarfBuzz guess the script and writing direction */ - hb_buffer_guess_segment_properties( buf ); - - /* shape buffer, which means conversion from character codes to */ - /* glyph indices, possibly applying a feature */ - hb_shape( font, buf, feature, feature ? 1 : 0 ); - - if ( feature ) - { - hb_buffer_t* hb_buf = metrics->globals->hb_buf; - - unsigned int gcount; - hb_glyph_info_t* ginfo; - - unsigned int hb_gcount; - hb_glyph_info_t* hb_ginfo; - - - /* we have to check whether applying a feature does actually change */ - /* glyph indices; otherwise the affected glyph or glyphs aren't */ - /* available at all in the feature */ - - hb_buffer_clear_contents( hb_buf ); - hb_buffer_add_utf8( hb_buf, p, len, 0, len ); - hb_buffer_guess_segment_properties( hb_buf ); - hb_shape( font, hb_buf, NULL, 0 ); - - ginfo = hb_buffer_get_glyph_infos( buf, &gcount ); - hb_ginfo = hb_buffer_get_glyph_infos( hb_buf, &hb_gcount ); - - if ( gcount == hb_gcount ) - { - unsigned int i; - - - for (i = 0; i < gcount; i++ ) - if ( ginfo[i].codepoint != hb_ginfo[i].codepoint ) - break; - - if ( i == gcount ) - { - /* both buffers have identical glyph indices */ - hb_buffer_clear_contents( buf ); - } - } - } - - *count = hb_buffer_get_length( buf ); - -#ifdef FT_DEBUG_LEVEL_TRACE - if ( feature && *count > 1 ) - FT_TRACE1(( "af_shaper_get_cluster:" - " input character mapped to multiple glyphs\n" )); -#endif - - return q; - } - - - FT_ULong - af_shaper_get_elem( AF_StyleMetrics metrics, - void* buf_, - unsigned int idx, - FT_Long* advance, - FT_Long* y_offset ) - { - hb_buffer_t* buf = (hb_buffer_t*)buf_; - hb_glyph_info_t* ginfo; - hb_glyph_position_t* gpos; - unsigned int gcount; - - FT_UNUSED( metrics ); - - - ginfo = hb_buffer_get_glyph_infos( buf, &gcount ); - gpos = hb_buffer_get_glyph_positions( buf, &gcount ); - - if ( idx >= gcount ) - return 0; - - if ( advance ) - *advance = gpos[idx].x_advance; - if ( y_offset ) - *y_offset = gpos[idx].y_offset; - - return ginfo[idx].codepoint; - } - - -#else /* !FT_CONFIG_OPTION_USE_HARFBUZZ */ - - - FT_Error - af_shaper_get_coverage( AF_FaceGlobals globals, - AF_StyleClass style_class, - FT_UShort* gstyles, - FT_Bool default_script ) - { - FT_UNUSED( globals ); - FT_UNUSED( style_class ); - FT_UNUSED( gstyles ); - FT_UNUSED( default_script ); - - return FT_Err_Ok; - } - - - void* - af_shaper_buf_create( FT_Face face ) - { - FT_Error error; - FT_Memory memory = face->memory; - FT_ULong* buf; - - - FT_MEM_ALLOC( buf, sizeof ( FT_ULong ) ); - - return (void*)buf; - } - - - void - af_shaper_buf_destroy( FT_Face face, - void* buf ) - { - FT_Memory memory = face->memory; - - - FT_FREE( buf ); - } - - - const char* - af_shaper_get_cluster( const char* p, - AF_StyleMetrics metrics, - void* buf_, - unsigned int* count ) - { - FT_Face face = metrics->globals->face; - FT_ULong ch, dummy = 0; - FT_ULong* buf = (FT_ULong*)buf_; - - - while ( *p == ' ' ) - p++; - - GET_UTF8_CHAR( ch, p ); - - /* since we don't have an engine to handle clusters, */ - /* we scan the characters but return zero */ - while ( !( *p == ' ' || *p == '\0' ) ) - GET_UTF8_CHAR( dummy, p ); - - if ( dummy ) - { - *buf = 0; - *count = 0; - } - else - { - *buf = FT_Get_Char_Index( face, ch ); - *count = 1; - } - - return p; - } - - - FT_ULong - af_shaper_get_elem( AF_StyleMetrics metrics, - void* buf_, - unsigned int idx, - FT_Long* advance, - FT_Long* y_offset ) - { - FT_Face face = metrics->globals->face; - FT_ULong glyph_index = *(FT_ULong*)buf_; - - FT_UNUSED( idx ); - - - if ( advance ) - FT_Get_Advance( face, - glyph_index, - FT_LOAD_NO_SCALE | - FT_LOAD_NO_HINTING | - FT_LOAD_IGNORE_TRANSFORM, - advance ); - - if ( y_offset ) - *y_offset = 0; - - return glyph_index; - } - - -#endif /* !FT_CONFIG_OPTION_USE_HARFBUZZ */ - - -/* END */ |