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kc3-lang/freetype/src/truetype/ttpload.c
Werner Lemberg
- src/truetype/ttpload.c
-
/**************************************************************************** * * ttpload.c * * TrueType-specific tables loader (body). * * Copyright (C) 1996-2020 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 <freetype/internal/ftdebug.h> #include <freetype/internal/ftobjs.h> #include <freetype/internal/ftstream.h> #include <freetype/tttags.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 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 ( FT_ERR_EQ( error, Table_Missing ) ) { face->glyf_len = 0; face->glyf_offset = 0; } else if ( error ) goto Exit; else { #ifdef FT_CONFIG_OPTION_INCREMENTAL if ( face->root.internal->incremental_interface ) face->glyf_offset = 0; else #endif face->glyf_offset = FT_STREAM_POS(); } FT_TRACE2(( "Locations " )); error = face->goto_table( face, TTAG_loca, stream, &table_len ); if ( error ) { error = FT_THROW( Locations_Missing ); goto Exit; } if ( face->header.Index_To_Loc_Format != 0 ) { shift = 2; if ( table_len >= 0x40000L ) { FT_TRACE2(( "table too large\n" )); table_len = 0x3FFFFL; } face->num_locations = table_len >> shift; } else { shift = 1; if ( table_len >= 0x20000L ) { FT_TRACE2(( "table too large\n" )); table_len = 0x1FFFFL; } face->num_locations = table_len >> shift; } if ( face->num_locations != (FT_ULong)face->root.num_glyphs + 1 ) { FT_TRACE2(( "glyph count mismatch! loca: %d, maxp: %d\n", face->num_locations - 1, face->root.num_glyphs )); /* we only handle the case where `maxp' gives a larger value */ if ( face->num_locations <= (FT_ULong)face->root.num_glyphs ) { FT_ULong new_loca_len = ( (FT_ULong)face->root.num_glyphs + 1 ) << shift; TT_Table entry = face->dir_tables; TT_Table limit = entry + face->num_tables; FT_Long pos = (FT_Long)FT_STREAM_POS(); FT_Long dist = 0x7FFFFFFFL; FT_Bool found = 0; /* compute the distance to next table in font file */ for ( ; entry < limit; entry++ ) { FT_Long diff = (FT_Long)entry->Offset - pos; if ( diff > 0 && diff < dist ) { dist = diff; found = 1; } } if ( !found ) { /* `loca' is the last table */ dist = (FT_Long)stream->size - pos; } if ( new_loca_len <= (FT_ULong)dist ) { face->num_locations = (FT_ULong)face->root.num_glyphs + 1; table_len = new_loca_len; FT_TRACE2(( "adjusting num_locations to %d\n", face->num_locations )); } else { face->root.num_glyphs = face->num_locations ? (FT_Long)face->num_locations - 1 : 0; FT_TRACE2(( "adjusting num_glyphs to %d\n", face->root.num_glyphs )); } } } /* * 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; } } /* Check broken location data. */ if ( pos1 > face->glyf_len ) { FT_TRACE1(( "tt_face_get_location:" " too large offset (0x%08lx) found for glyph index %ld,\n" " " " exceeding the end of `glyf' table (0x%08lx)\n", pos1, gindex, face->glyf_len )); *asize = 0; return 0; } if ( pos2 > face->glyf_len ) { /* We try to sanitize the last `loca' entry. */ if ( gindex == face->num_locations - 2 ) { FT_TRACE1(( "tt_face_get_location:" " too large size (%ld bytes) found for glyph index %ld,\n" " " " truncating at the end of `glyf' table to %ld bytes\n", pos2 - pos1, gindex, face->glyf_len - pos1 )); pos2 = face->glyf_len; } else { FT_TRACE1(( "tt_face_get_location:" " too large offset (0x%08lx) found for glyph index %ld,\n" " " " exceeding the end of `glyf' table (0x%08lx)\n", pos2, gindex + 1, face->glyf_len )); *asize = 0; return 0; } } /* 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 = FT_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_Int32* cur = face->cvt; FT_Int32* limit = cur + face->cvt_size; for ( ; cur < limit; cur++ ) *cur = FT_GET_SHORT() * 64; } 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 FT_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 = FT_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 FT_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 = FT_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 FT_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 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 FT_Err_Ok; if ( FT_FRAME_EXTRACT( table_size, face->hdmx_table ) ) goto Exit; p = face->hdmx_table; limit = p + table_size; /* Given that `hdmx' tables are losing its importance (for example, */ /* variation fonts introduced in OpenType 1.8 must not have this */ /* table) we no longer test for a correct `version' field. */ p += 2; 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, thus */ /* explaining why `record_size' is a long (which we read as */ /* unsigned long for convenience). In practice, two bytes are */ /* 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 ( num_records > 255 || ( num_records > 0 && ( record_size > 0x10001L || record_size < 4 ) ) ) { error = FT_THROW( 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 = FT_OFFSET( 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 */