Handle GSUB Lookup type 8, and ReverseChainContextualSubst table. (bug
2006-01-30 Behdad Esfahbod <behdad@gnome.org>
* pango/opentype/ftxgsub.c: Handle GSUB Lookup type 8,
and ReverseChainContextualSubst table. (bug #149696,
patch from Aamir Wali)
This commit is contained in:
Behdad Esfahbod
Behdad Esfahbod
parent
e040f68196
commit
8228828e1e
375
src/ftxgsub.c
375
src/ftxgsub.c
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@ -1911,8 +1911,7 @@
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}
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static FT_Error Lookup_ContextSubst1(
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TTO_GSUBHeader* gsub,
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static FT_Error Lookup_ContextSubst1( TTO_GSUBHeader* gsub,
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TTO_ContextSubstFormat1* csf1,
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OTL_Buffer buffer,
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FT_UShort flags,
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@ -1975,8 +1974,7 @@
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}
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static FT_Error Lookup_ContextSubst2(
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TTO_GSUBHeader* gsub,
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static FT_Error Lookup_ContextSubst2( TTO_GSUBHeader* gsub,
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TTO_ContextSubstFormat2* csf2,
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OTL_Buffer buffer,
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FT_UShort flags,
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@ -2083,8 +2081,7 @@
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}
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static FT_Error Lookup_ContextSubst3(
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TTO_GSUBHeader* gsub,
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static FT_Error Lookup_ContextSubst3( TTO_GSUBHeader* gsub,
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TTO_ContextSubstFormat3* csf3,
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OTL_Buffer buffer,
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FT_UShort flags,
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@ -3187,8 +3184,7 @@
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}
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static FT_Error Lookup_ChainContextSubst1(
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TTO_GSUBHeader* gsub,
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static FT_Error Lookup_ChainContextSubst1( TTO_GSUBHeader* gsub,
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TTO_ChainContextSubstFormat1* ccsf1,
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OTL_Buffer buffer,
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FT_UShort flags,
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@ -3315,8 +3311,7 @@
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}
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static FT_Error Lookup_ChainContextSubst2(
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TTO_GSUBHeader* gsub,
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static FT_Error Lookup_ChainContextSubst2( TTO_GSUBHeader* gsub,
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TTO_ChainContextSubstFormat2* ccsf2,
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OTL_Buffer buffer,
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FT_UShort flags,
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@ -3518,8 +3513,7 @@
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}
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static FT_Error Lookup_ChainContextSubst3(
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TTO_GSUBHeader* gsub,
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static FT_Error Lookup_ChainContextSubst3( TTO_GSUBHeader* gsub,
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TTO_ChainContextSubstFormat3* ccsf3,
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OTL_Buffer buffer,
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FT_UShort flags,
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@ -3628,8 +3622,7 @@
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}
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static FT_Error Lookup_ChainContextSubst(
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TTO_GSUBHeader* gsub,
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static FT_Error Lookup_ChainContextSubst( TTO_GSUBHeader* gsub,
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TTO_GSUB_SubTable* st,
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OTL_Buffer buffer,
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FT_UShort flags,
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@ -3663,6 +3656,287 @@
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}
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FT_Error Load_ReverseChainContextSubst( TTO_ReverseChainContextSubst* rccs,
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FT_Stream stream )
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{
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FT_Error error;
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FT_Memory memory = stream->memory;
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FT_UShort m, count;
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FT_UShort nb = 0, nl = 0, n;
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FT_UShort backtrack_count, lookahead_count;
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FT_ULong cur_offset, new_offset, base_offset;
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TTO_Coverage* b;
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TTO_Coverage* l;
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FT_UShort* sub;
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base_offset = FILE_Pos();
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if ( ACCESS_Frame( 2L ) )
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return error;
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rccs->SubstFormat = GET_UShort();
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if ( rccs->SubstFormat != 1 )
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return TTO_Err_Invalid_GSUB_SubTable_Format;
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FORGET_Frame();
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if ( ACCESS_Frame( 2L ) )
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return error;
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new_offset = GET_UShort() + base_offset;
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FORGET_Frame();
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cur_offset = FILE_Pos();
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if ( FILE_Seek( new_offset ) ||
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( error = Load_Coverage( &rccs->Coverage, stream ) ) != TT_Err_Ok )
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return error;
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(void)FILE_Seek( cur_offset );
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if ( ACCESS_Frame( 2L ) )
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goto Fail4;
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rccs->BacktrackGlyphCount = GET_UShort();
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FORGET_Frame();
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rccs->BacktrackCoverage = NULL;
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backtrack_count = rccs->BacktrackGlyphCount;
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if ( ALLOC_ARRAY( rccs->BacktrackCoverage, backtrack_count,
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TTO_Coverage ) )
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goto Fail4;
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b = rccs->BacktrackCoverage;
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for ( nb = 0; nb < backtrack_count; nb++ )
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{
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if ( ACCESS_Frame( 2L ) )
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goto Fail3;
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new_offset = GET_UShort() + base_offset;
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FORGET_Frame();
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cur_offset = FILE_Pos();
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if ( FILE_Seek( new_offset ) ||
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( error = Load_Coverage( &b[nb], stream ) ) != TT_Err_Ok )
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goto Fail3;
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(void)FILE_Seek( cur_offset );
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}
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if ( ACCESS_Frame( 2L ) )
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goto Fail3;
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rccs->LookaheadGlyphCount = GET_UShort();
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FORGET_Frame();
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rccs->LookaheadCoverage = NULL;
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lookahead_count = rccs->LookaheadGlyphCount;
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if ( ALLOC_ARRAY( rccs->LookaheadCoverage, lookahead_count,
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TTO_Coverage ) )
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goto Fail3;
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l = rccs->LookaheadCoverage;
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for ( nl = 0; nl < lookahead_count; nl++ )
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{
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if ( ACCESS_Frame( 2L ) )
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goto Fail2;
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new_offset = GET_UShort() + base_offset;
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FORGET_Frame();
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cur_offset = FILE_Pos();
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if ( FILE_Seek( new_offset ) ||
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( error = Load_Coverage( &l[nl], stream ) ) != TT_Err_Ok )
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goto Fail2;
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(void)FILE_Seek( cur_offset );
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}
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if ( ACCESS_Frame( 2L ) )
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goto Fail2;
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rccs->GlyphCount = GET_UShort();
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FORGET_Frame();
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rccs->Substitute = NULL;
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count = rccs->GlyphCount;
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if ( ALLOC_ARRAY( rccs->Substitute, count,
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FT_UShort ) )
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goto Fail2;
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sub = rccs->Substitute;
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if ( ACCESS_Frame( count * 2L ) )
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goto Fail1;
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for ( n = 0; n < count; n++ )
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sub[n] = GET_UShort();
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FORGET_Frame();
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return TT_Err_Ok;
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Fail1:
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FREE( sub );
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Fail2:
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for ( m = 0; m < nl; m++ )
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Free_Coverage( &l[m], memory );
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FREE( l );
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Fail3:
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for ( m = 0; m < nb; m++ )
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Free_Coverage( &b[m], memory );
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FREE( b );
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Fail4:
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Free_Coverage( &rccs->Coverage, memory );
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return error;
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}
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void Free_ReverseChainContextSubst( TTO_ReverseChainContextSubst* rccs,
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FT_Memory memory )
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{
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FT_UShort n, count;
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TTO_Coverage* c;
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Free_Coverage( &rccs->Coverage, memory );
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if ( rccs->LookaheadCoverage )
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{
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count = rccs->LookaheadGlyphCount;
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c = rccs->LookaheadCoverage;
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for ( n = 0; n < count; n++ )
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Free_Coverage( &c[n], memory );
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FREE( c );
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}
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if ( rccs->BacktrackCoverage )
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{
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count = rccs->BacktrackGlyphCount;
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c = rccs->BacktrackCoverage;
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for ( n = 0; n < count; n++ )
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Free_Coverage( &c[n], memory );
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FREE( c );
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}
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FREE ( rccs->Substitute );
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}
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static FT_Error Lookup_ReverseChainContextSubst( TTO_GSUBHeader* gsub,
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TTO_GSUB_SubTable* st,
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OTL_Buffer buffer,
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FT_UShort flags,
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/* note different signature here: */ FT_ULong string_index )
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{
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FT_UShort index, input_index, i, j, property;
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FT_UShort bgc, lgc;
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FT_Error error;
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TTO_ReverseChainContextSubst* rccs = &st->reverse;
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TTO_Coverage* bc;
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TTO_Coverage* lc;
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TTO_GDEFHeader* gdef;
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gdef = gsub->gdef;
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if ( CHECK_Property( gdef, IN_ITEM( string_index ), flags, &property ) )
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return error;
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bgc = rccs->BacktrackGlyphCount;
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lgc = rccs->LookaheadGlyphCount;
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/* check whether context is too long; it is a first guess only */
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if ( bgc > string_index || string_index + 1 + lgc > buffer->in_length )
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return TTO_Err_Not_Covered;
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if ( bgc )
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{
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/* Since we don't know in advance the number of glyphs to inspect,
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we search backwards for matches in the backtrack glyph array */
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bc = rccs->BacktrackCoverage;
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for ( i = 0, j = string_index - 1; i < bgc; i++, j-- )
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{
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while ( CHECK_Property( gdef, IN_ITEM( j ), flags, &property ) )
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{
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if ( error && error != TTO_Err_Not_Covered )
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return error;
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if ( j + 1 == bgc - i )
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return TTO_Err_Not_Covered;
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j--;
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}
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error = Coverage_Index( &bc[i], IN_GLYPH( j ), &index );
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if ( error )
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return error;
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}
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}
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j = string_index;
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error = Coverage_Index( &rccs->Coverage, IN_GLYPH( j ), &input_index );
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if ( error )
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return error;
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/* we are starting for lookahead glyphs right after the last context
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glyph */
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j += 1;
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lc = rccs->LookaheadCoverage;
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for ( i = 0; i < lgc; i++, j++ )
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{
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while ( CHECK_Property( gdef, IN_ITEM( j ), flags, &property ) )
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{
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if ( error && error != TTO_Err_Not_Covered )
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return error;
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if ( j + lgc - i == buffer->in_length )
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return TTO_Err_Not_Covered;
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j++;
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}
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error = Coverage_Index( &lc[i], IN_GLYPH( j ), &index );
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if ( error )
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return error;
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}
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IN_GLYPH( string_index ) = rccs->Substitute[input_index];
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return error;
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}
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/***********
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* GSUB API
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@ -3974,6 +4248,11 @@
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Lookup_ChainContextSubst, /* GSUB_LOOKUP_CHAIN 6 */
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Lookup_DefaultSubst, /* GSUB_LOOKUP_EXTENSION 7 */
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};
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/* Note that the following lookup does not belong to the table above:
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* Lookup_ReverseChainContextSubst, GSUB_LOOKUP_REVERSE_CHAIN 8
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* because it's invalid to happen where this table is used. It's
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* signature is different too...
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*/
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/* Do an individual subtable lookup. Returns TT_Err_Ok if substitution
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has been done, or TTO_Err_Not_Covered if not. */
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@ -4065,6 +4344,47 @@
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}
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static FT_Error Apply_ReverseChainContextSubst( TTO_GSUBHeader* gsub,
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FT_UShort lookup_index,
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OTL_Buffer buffer )
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{
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FT_UInt* properties = gsub->LookupList.Properties;
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FT_Error error, retError = TTO_Err_Not_Covered;
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FT_ULong subtable_Count, string_index;
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FT_UShort flags;
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TTO_Lookup* lo;
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if ( buffer->in_length == 0 )
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return TTO_Err_Not_Covered;
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lo = &gsub->LookupList.Lookup[lookup_index];
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flags = lo->LookupFlag;
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for ( subtable_Count = 0; subtable_Count < lo->SubTableCount; subtable_Count++ )
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{
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string_index = buffer->in_length - 1;
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do
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{
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if ( ~IN_PROPERTIES( buffer->in_pos ) & properties[lookup_index] )
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{
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error = Lookup_ReverseChainContextSubst( gsub, &lo->SubTable[subtable_Count].st.gsub,
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buffer, flags, string_index );
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if ( error )
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{
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if ( error != TTO_Err_Not_Covered )
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return error;
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}
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else
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retError = error;
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}
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}
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while (string_index--);
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}
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return retError;
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}
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EXPORT_FUNC
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FT_Error TT_GSUB_Add_Feature( TTO_GSUBHeader* gsub,
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FT_UShort feature_index,
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@ -4145,8 +4465,7 @@
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OTL_Buffer buffer )
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{
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FT_Error error, retError = TTO_Err_Not_Covered;
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FT_UShort i, j, feature_index, lookup_count;
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TTO_Feature feature;
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FT_UShort i, j, lookup_count;
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if ( !gsub ||
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!buffer || buffer->in_length == 0 || buffer->in_pos >= buffer->in_length )
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@ -4156,18 +4475,37 @@
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for ( i = 0; i < gsub->FeatureList.ApplyCount; i++)
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{
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FT_UShort feature_index;
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TTO_Feature feature;
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feature_index = gsub->FeatureList.ApplyOrder[i];
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feature = gsub->FeatureList.FeatureRecord[feature_index].Feature;
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for ( j = 0; j < feature.LookupListCount; j++ )
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{
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FT_UShort lookup_index = feature.LookupListIndex[j];
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FT_UShort lookup_index;
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TTO_Lookup* lookup;
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FT_Bool need_swap;
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lookup_index = feature.LookupListIndex[j];
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/* Skip nonexistant lookups */
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if (lookup_index >= lookup_count)
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continue;
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lookup = &gsub->LookupList.Lookup[lookup_index];
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if ( lookup->LookupType == GSUB_LOOKUP_REVERSE_CHAIN )
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{
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error = Apply_ReverseChainContextSubst( gsub, lookup_index, buffer);
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need_swap = FALSE; /* We do ReverseChainContextSubst in-place */
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}
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else
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{
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error = Do_String_Lookup( gsub, lookup_index, buffer );
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need_swap = TRUE;
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}
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if ( error )
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{
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if ( error != TTO_Err_Not_Covered )
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@ -4176,11 +4514,14 @@
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else
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retError = error;
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if ( need_swap )
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{
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error = otl_buffer_swap( buffer );
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if ( error )
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goto End;
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}
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}
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}
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error = retError;
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@ -39,7 +39,7 @@ extern "C" {
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#define GSUB_LOOKUP_CONTEXT 5
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#define GSUB_LOOKUP_CHAIN 6
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#define GSUB_LOOKUP_EXTENSION 7
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#define GSUB_LOOKUP_REVERSE_CHAIN 8
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/* Use this if a feature applies to all glyphs */
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@ -467,6 +467,24 @@ extern "C" {
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typedef struct TTO_ChainContextSubst_ TTO_ChainContextSubst;
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/* LookupType 8 */
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struct TTO_ReverseChainContextSubst_
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{
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FT_UShort SubstFormat; /* always 1 */
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TTO_Coverage Coverage; /* coverage table for input glyphs */
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FT_UShort BacktrackGlyphCount; /* number of backtrack glyphs */
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TTO_Coverage* BacktrackCoverage; /* array of backtrack Coverage
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tables */
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FT_UShort LookaheadGlyphCount; /* number of lookahead glyphs */
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TTO_Coverage* LookaheadCoverage; /* array of lookahead Coverage
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tables */
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FT_UShort GlyphCount; /* number of Glyph IDs */
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FT_UShort* Substitute; /* array of substitute Glyph ID */
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};
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|
||||
typedef struct TTO_ReverseChainContextSubst_ TTO_ReverseChainContextSubst;
|
||||
|
||||
|
||||
union TTO_GSUB_SubTable_
|
||||
{
|
||||
TTO_SingleSubst single;
|
||||
|
|
@ -475,6 +493,7 @@ extern "C" {
|
|||
TTO_LigatureSubst ligature;
|
||||
TTO_ContextSubst context;
|
||||
TTO_ChainContextSubst chain;
|
||||
TTO_ReverseChainContextSubst reverse;
|
||||
};
|
||||
|
||||
typedef union TTO_GSUB_SubTable_ TTO_GSUB_SubTable;
|
||||
|
|
|
|||
|
|
@ -470,6 +470,9 @@
|
|||
case GSUB_LOOKUP_CHAIN:
|
||||
return Load_ChainContextSubst( &st->st.gsub.chain, stream );
|
||||
|
||||
case GSUB_LOOKUP_REVERSE_CHAIN:
|
||||
return Load_ReverseChainContextSubst( &st->st.gsub.reverse, stream );
|
||||
|
||||
default:
|
||||
return TTO_Err_Invalid_GSUB_SubTable_Format;
|
||||
}
|
||||
|
|
@ -536,6 +539,10 @@
|
|||
Free_ContextSubst( &st->st.gsub.context, memory );
|
||||
break;
|
||||
|
||||
case GSUB_LOOKUP_REVERSE_CHAIN:
|
||||
Free_ReverseChainContextSubst( &st->st.gsub.reverse, memory );
|
||||
break;
|
||||
|
||||
case GSUB_LOOKUP_CHAIN:
|
||||
Free_ChainContextSubst( &st->st.gsub.chain, memory );
|
||||
break;
|
||||
|
|
|
|||
|
|
@ -74,6 +74,8 @@ extern "C" {
|
|||
FT_Stream input );
|
||||
FT_Error Load_ChainContextSubst( TTO_ChainContextSubst* ccs,
|
||||
FT_Stream input );
|
||||
FT_Error Load_ReverseChainContextSubst( TTO_ReverseChainContextSubst* rccs,
|
||||
FT_Stream input );
|
||||
|
||||
void Free_SingleSubst( TTO_SingleSubst* ss,
|
||||
FT_Memory memory );
|
||||
|
|
@ -87,7 +89,8 @@ extern "C" {
|
|||
FT_Memory memory );
|
||||
void Free_ChainContextSubst( TTO_ChainContextSubst* ccs,
|
||||
FT_Memory memory );
|
||||
|
||||
void Free_ReverseChainContextSubst( TTO_ReverseChainContextSubst* rccs,
|
||||
FT_Memory memory );
|
||||
|
||||
/* functions from ftxgpos.c */
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue