Edit
kc3-lang/freetype/src/truetype/ttpload.c
Werner Lemberg
- src/truetype/ttpload.c
-
/***************************************************************************/ /* */ /* ttpload.c */ /* */ /* TrueType-specific tables loader (body). */ /* */ /* Copyright 1996-2001, 2002, 2004, 2005, 2006, 2007, 2008, 2009 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_INTERNAL_DEBUG_H #include FT_INTERNAL_OBJECTS_H #include FT_INTERNAL_STREAM_H #include FT_TRUETYPE_TAGS_H #include "ttpload.h" #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT #include "ttgxvar.h" #endif #include "tterrors.h" /*************************************************************************/ /* */ /* 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_ttpload /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_loca */ /* */ /* <Description> */ /* Load the locations table. */ /* */ /* <InOut> */ /* face :: A handle to the target face object. */ /* */ /* <Input> */ /* stream :: The input stream. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) tt_face_load_loca( TT_Face face, FT_Stream stream ) { FT_Error error; FT_ULong table_len; FT_Int shift; /* we need the size of the `glyf' table for malformed `loca' tables */ error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len ); /* it is possible that a font doesn't have a glyf table at all */ /* or its size is zero */ if ( error == TT_Err_Table_Missing ) face->glyf_len = 0; else if ( error ) goto Exit; FT_TRACE2(( "Locations " )); error = face->goto_table( face, TTAG_loca, stream, &table_len ); if ( error ) { error = TT_Err_Locations_Missing; goto Exit; } if ( face->header.Index_To_Loc_Format != 0 ) { shift = 2; if ( table_len >= 0x40000L ) { FT_TRACE2(( "table too large!\n" )); error = TT_Err_Invalid_Table; goto Exit; } face->num_locations = (FT_UInt)( table_len >> shift ); } else { shift = 1; if ( table_len >= 0x20000L ) { FT_TRACE2(( "table too large!\n" )); error = TT_Err_Invalid_Table; goto Exit; } face->num_locations = (FT_UInt)( table_len >> shift ); } if ( face->num_locations != (FT_UInt)face->root.num_glyphs ) { FT_TRACE2(( "glyph count mismatch! loca: %d, maxp: %d\n", face->num_locations, face->root.num_glyphs )); /* we only handle the case where `maxp' gives a larger value */ if ( face->num_locations < (FT_UInt)face->root.num_glyphs ) { FT_Long new_loca_len = (FT_Long)face->root.num_glyphs << shift; TT_Table entry = face->dir_tables; TT_Table limit = entry + face->num_tables; FT_Long pos = FT_Stream_Pos( stream ); FT_Long dist = 0x7FFFFFFFL; /* compute the distance to next table in font file */ for ( ; entry < limit; entry++ ) { FT_Long diff = entry->Offset - pos; if ( diff > 0 && diff < dist ) dist = diff; } if ( new_loca_len <= dist ) { face->num_locations = (FT_Long)face->root.num_glyphs; table_len = new_loca_len; FT_TRACE2(( "adjusting num_locations to %d\n", face->num_locations )); } } } /* * Extract the frame. We don't need to decompress it since * we are able to parse it directly. */ if ( FT_FRAME_EXTRACT( table_len, face->glyph_locations ) ) goto Exit; FT_TRACE2(( "loaded\n" )); Exit: return error; } FT_LOCAL_DEF( FT_ULong ) tt_face_get_location( TT_Face face, FT_UInt gindex, FT_UInt *asize ) { FT_ULong pos1, pos2; FT_Byte* p; FT_Byte* p_limit; pos1 = pos2 = 0; if ( gindex < face->num_locations ) { if ( face->header.Index_To_Loc_Format != 0 ) { p = face->glyph_locations + gindex * 4; p_limit = face->glyph_locations + face->num_locations * 4; pos1 = FT_NEXT_ULONG( p ); pos2 = pos1; if ( p + 4 <= p_limit ) pos2 = FT_NEXT_ULONG( p ); } else { p = face->glyph_locations + gindex * 2; p_limit = face->glyph_locations + face->num_locations * 2; pos1 = FT_NEXT_USHORT( p ); pos2 = pos1; if ( p + 2 <= p_limit ) pos2 = FT_NEXT_USHORT( p ); pos1 <<= 1; pos2 <<= 1; } } /* The `loca' table must be ordered; it refers to the length of */ /* an entry as the difference between the current and the next */ /* position. However, there do exist (malformed) fonts which */ /* don't obey this rule, so we are only able to provide an */ /* upper bound for the size. */ /* */ /* We get (intentionally) a wrong, non-zero result in case the */ /* `glyf' table is missing. */ if ( pos2 >= pos1 ) *asize = (FT_UInt)( pos2 - pos1 ); else *asize = (FT_UInt)( face->glyf_len - pos1 ); return pos1; } FT_LOCAL_DEF( void ) tt_face_done_loca( TT_Face face ) { FT_Stream stream = face->root.stream; FT_FRAME_RELEASE( face->glyph_locations ); face->num_locations = 0; } /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_cvt */ /* */ /* <Description> */ /* Load the control value table into a face object. */ /* */ /* <InOut> */ /* face :: A handle to the target face object. */ /* */ /* <Input> */ /* stream :: A handle to the input stream. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) tt_face_load_cvt( TT_Face face, FT_Stream stream ) { #ifdef TT_USE_BYTECODE_INTERPRETER FT_Error error; FT_Memory memory = stream->memory; FT_ULong table_len; FT_TRACE2(( "CVT " )); error = face->goto_table( face, TTAG_cvt, stream, &table_len ); if ( error ) { FT_TRACE2(( "is missing!\n" )); face->cvt_size = 0; face->cvt = NULL; error = TT_Err_Ok; goto Exit; } face->cvt_size = table_len / 2; if ( FT_NEW_ARRAY( face->cvt, face->cvt_size ) ) goto Exit; if ( FT_FRAME_ENTER( face->cvt_size * 2L ) ) goto Exit; { FT_Short* cur = face->cvt; FT_Short* limit = cur + face->cvt_size; for ( ; cur < limit; cur++ ) *cur = FT_GET_SHORT(); } FT_FRAME_EXIT(); FT_TRACE2(( "loaded\n" )); #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT if ( face->doblend ) error = tt_face_vary_cvt( face, stream ); #endif Exit: return error; #else /* !TT_USE_BYTECODE_INTERPRETER */ FT_UNUSED( face ); FT_UNUSED( stream ); return TT_Err_Ok; #endif } /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_fpgm */ /* */ /* <Description> */ /* Load the font program. */ /* */ /* <InOut> */ /* face :: A handle to the target face object. */ /* */ /* <Input> */ /* stream :: A handle to the input stream. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) tt_face_load_fpgm( TT_Face face, FT_Stream stream ) { #ifdef TT_USE_BYTECODE_INTERPRETER FT_Error error; FT_ULong table_len; FT_TRACE2(( "Font program " )); /* The font program is optional */ error = face->goto_table( face, TTAG_fpgm, stream, &table_len ); if ( error ) { face->font_program = NULL; face->font_program_size = 0; error = TT_Err_Ok; FT_TRACE2(( "is missing!\n" )); } else { face->font_program_size = table_len; if ( FT_FRAME_EXTRACT( table_len, face->font_program ) ) goto Exit; FT_TRACE2(( "loaded, %12d bytes\n", face->font_program_size )); } Exit: return error; #else /* !TT_USE_BYTECODE_INTERPRETER */ FT_UNUSED( face ); FT_UNUSED( stream ); return TT_Err_Ok; #endif } /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_prep */ /* */ /* <Description> */ /* Load the cvt program. */ /* */ /* <InOut> */ /* face :: A handle to the target face object. */ /* */ /* <Input> */ /* stream :: A handle to the input stream. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) tt_face_load_prep( TT_Face face, FT_Stream stream ) { #ifdef TT_USE_BYTECODE_INTERPRETER FT_Error error; FT_ULong table_len; FT_TRACE2(( "Prep program " )); error = face->goto_table( face, TTAG_prep, stream, &table_len ); if ( error ) { face->cvt_program = NULL; face->cvt_program_size = 0; error = TT_Err_Ok; FT_TRACE2(( "is missing!\n" )); } else { face->cvt_program_size = table_len; if ( FT_FRAME_EXTRACT( table_len, face->cvt_program ) ) goto Exit; FT_TRACE2(( "loaded, %12d bytes\n", face->cvt_program_size )); } Exit: return error; #else /* !TT_USE_BYTECODE_INTERPRETER */ FT_UNUSED( face ); FT_UNUSED( stream ); return TT_Err_Ok; #endif } /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_hdmx */ /* */ /* <Description> */ /* Load the `hdmx' table into the face object. */ /* */ /* <Input> */ /* face :: A handle to the target face object. */ /* */ /* stream :: A handle to the input stream. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) tt_face_load_hdmx( TT_Face face, FT_Stream stream ) { FT_Error error; FT_Memory memory = stream->memory; FT_UInt version, nn, num_records; FT_ULong table_size, record_size; FT_Byte* p; FT_Byte* limit; /* this table is optional */ error = face->goto_table( face, TTAG_hdmx, stream, &table_size ); if ( error || table_size < 8 ) return TT_Err_Ok; if ( FT_FRAME_EXTRACT( table_size, face->hdmx_table ) ) goto Exit; p = face->hdmx_table; limit = p + table_size; version = FT_NEXT_USHORT( p ); num_records = FT_NEXT_USHORT( p ); record_size = FT_NEXT_ULONG( p ); /* The maximum number of bytes in an hdmx device record is the */ /* maximum number of glyphs + 2; this is 0xFFFF + 2; this is */ /* the reason why `record_size' is a long (which we read as */ /* unsigned long for convenience). In practice, two bytes */ /* sufficient to hold the size value. */ /* */ /* There are at least two fonts, HANNOM-A and HANNOM-B version */ /* 2.0 (2005), which get this wrong: The upper two bytes of */ /* the size value are set to 0xFF instead of 0x00. We catch */ /* and fix this. */ if ( record_size >= 0xFFFF0000UL ) record_size &= 0xFFFFU; /* The limit for `num_records' is a heuristic value. */ if ( version != 0 || num_records > 255 || record_size > 0x10001L ) { error = TT_Err_Invalid_File_Format; goto Fail; } if ( FT_NEW_ARRAY( face->hdmx_record_sizes, num_records ) ) goto Fail; for ( nn = 0; nn < num_records; nn++ ) { if ( p + record_size > limit ) break; face->hdmx_record_sizes[nn] = p[0]; p += record_size; } face->hdmx_record_count = nn; face->hdmx_table_size = table_size; face->hdmx_record_size = record_size; Exit: return error; Fail: FT_FRAME_RELEASE( face->hdmx_table ); face->hdmx_table_size = 0; goto Exit; } FT_LOCAL_DEF( void ) tt_face_free_hdmx( TT_Face face ) { FT_Stream stream = face->root.stream; FT_Memory memory = stream->memory; FT_FREE( face->hdmx_record_sizes ); FT_FRAME_RELEASE( face->hdmx_table ); } /*************************************************************************/ /* */ /* Return the advance width table for a given pixel size if it is found */ /* in the font's `hdmx' table (if any). */ /* */ FT_LOCAL_DEF( FT_Byte* ) tt_face_get_device_metrics( TT_Face face, FT_UInt ppem, FT_UInt gindex ) { FT_UInt nn; FT_Byte* result = NULL; FT_ULong record_size = face->hdmx_record_size; FT_Byte* record = face->hdmx_table + 8; for ( nn = 0; nn < face->hdmx_record_count; nn++ ) if ( face->hdmx_record_sizes[nn] == ppem ) { gindex += 2; if ( gindex < record_size ) result = record + nn * record_size + gindex; break; } return result; } /* END */