ttpload.c
上传用户：yisoukefu
上传日期：2020-08-09
资源大小：39506k
文件大小：18k
- /***************************************************************************/
- /* */
- /* ttpload.c */
- /* */
- /* TrueType-specific tables loader (body). */
- /* */
- /* Copyright 1996-2001, 2002, 2004, 2005, 2006, 2007 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;
- /* we need the size of the `glyf' table for malformed `loca' tables */
- error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len );
- 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 )
- {
- if ( table_len >= 0x40000L )
- {
- FT_TRACE2(( "table too large!n" ));
- error = TT_Err_Invalid_Table;
- goto Exit;
- }
- face->num_locations = (FT_UInt)( table_len >> 2 );
- }
- else
- {
- if ( table_len >= 0x20000L )
- {
- FT_TRACE2(( "table too large!n" ));
- error = TT_Err_Invalid_Table;
- goto Exit;
- }
- face->num_locations = (FT_UInt)( table_len >> 1 );
- }
- /*
- * 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(( "loadedn" ));
- 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;
- }
- }
- /* It isn't mentioned explicitly that the `loca' table must be */
- /* ordered, but implicitly it refers to the length of an entry */
- /* as the difference between the current and the next position. */
- /* Anyway, there do exist (malformed) fonts which don't obey */
- /* this rule, so we are only able to provide an upper bound for */
- /* the size. */
- 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(( "loadedn" ));
- #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 bytesn", 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 bytesn", 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 */
English
