/***************************************************************************/
/* */
/* cffdecode.c */
/* */
/* PostScript CFF (Type 2) decoding routines (body). */
/* */
/* Copyright 2017-2018 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 FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_SERVICE_H
#include FT_SERVICE_CFF_TABLE_LOAD_H
#include "cffdecode.h"
#include "psobjs.h"
#include "psauxerr.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_cffdecode
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/********** *********/
/********** *********/
/********** GENERIC CHARSTRING PARSING *********/
/********** *********/
/********** *********/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* <Function> */
/* cff_compute_bias */
/* */
/* <Description> */
/* Computes the bias value in dependence of the number of glyph */
/* subroutines. */
/* */
/* <Input> */
/* in_charstring_type :: The `CharstringType' value of the top DICT */
/* dictionary. */
/* */
/* num_subrs :: The number of glyph subroutines. */
/* */
/* <Return> */
/* The bias value. */
static FT_Int
cff_compute_bias( FT_Int in_charstring_type,
FT_UInt num_subrs )
{
FT_Int result;
if ( in_charstring_type == 1 )
result = 0;
else if ( num_subrs < 1240 )
result = 107;
else if ( num_subrs < 33900U )
result = 1131;
else
result = 32768U;
return result;
}
FT_LOCAL_DEF( FT_Int )
cff_lookup_glyph_by_stdcharcode( CFF_Font cff,
FT_Int charcode )
{
FT_UInt n;
FT_UShort glyph_sid;
FT_Service_CFFLoad cffload;
/* CID-keyed fonts don't have glyph names */
if ( !cff->charset.sids )
return -1;
/* check range of standard char code */
if ( charcode < 0 || charcode > 255 )
return -1;
cffload = (FT_Service_CFFLoad)cff->cffload;
/* Get code to SID mapping from `cff_standard_encoding'. */
glyph_sid = cffload->get_standard_encoding( (FT_UInt)charcode );
for ( n = 0; n < cff->num_glyphs; n++ )
{
if ( cff->charset.sids[n] == glyph_sid )
return (FT_Int)n;
}
return -1;
}
/*************************************************************************/
/* */
/* <Function> */
/* cff_decoder_init */
/* */
/* <Description> */
/* Initializes a given glyph decoder. */
/* */
/* <InOut> */
/* decoder :: A pointer to the glyph builder to initialize. */
/* */
/* <Input> */
/* face :: The current face object. */
/* */
/* size :: The current size object. */
/* */
/* slot :: The current glyph object. */
/* */
/* hinting :: Whether hinting is active. */
/* */
/* hint_mode :: The hinting mode. */
/* */
FT_LOCAL_DEF( void )
cff_decoder_init( CFF_Decoder* decoder,
TT_Face face,
CFF_Size size,
CFF_GlyphSlot slot,
FT_Bool hinting,
FT_Render_Mode hint_mode,
CFF_Decoder_Get_Glyph_Callback get_callback,
CFF_Decoder_Free_Glyph_Callback free_callback )
{
CFF_Font cff = (CFF_Font)face->extra.data;
/* clear everything */
FT_ZERO( decoder );
/* initialize builder */
cff_builder_init( &decoder->builder, face, size, slot, hinting );
/* initialize Type2 decoder */
decoder->cff = cff;
decoder->num_globals = cff->global_subrs_index.count;
decoder->globals = cff->global_subrs;
decoder->globals_bias = cff_compute_bias(
cff->top_font.font_dict.charstring_type,
decoder->num_globals );
decoder->hint_mode = hint_mode;
decoder->get_glyph_callback = get_callback;
decoder->free_glyph_callback = free_callback;
}
/* this function is used to select the subfont */
/* and the locals subrs array */
FT_LOCAL_DEF( FT_Error )
cff_decoder_prepare( CFF_Decoder* decoder,
CFF_Size size,
FT_UInt glyph_index )
{
CFF_Builder *builder = &decoder->builder;
CFF_Font cff = (CFF_Font)builder->face->extra.data;
CFF_SubFont sub = &cff->top_font;
FT_Error error = FT_Err_Ok;
FT_Service_CFFLoad cffload = (FT_Service_CFFLoad)cff->cffload;
/* manage CID fonts */
if ( cff->num_subfonts )
{
FT_Byte fd_index = cffload->fd_select_get( &cff->fd_select,
glyph_index );
if ( fd_index >= cff->num_subfonts )
{
FT_TRACE4(( "cff_decoder_prepare: invalid CID subfont index\n" ));
error = FT_THROW( Invalid_File_Format );
goto Exit;
}
FT_TRACE3(( " in subfont %d:\n", fd_index ));
sub = cff->subfonts[fd_index];
if ( builder->hints_funcs && size )
{
FT_Size ftsize = FT_SIZE( size );
CFF_Internal internal = (CFF_Internal)ftsize->internal->module_data;
/* for CFFs without subfonts, this value has already been set */
builder->hints_globals = (void *)internal->subfonts[fd_index];
}
}
decoder->num_locals = sub->local_subrs_index.count;
decoder->locals = sub->local_subrs;
decoder->locals_bias = cff_compute_bias(
decoder->cff->top_font.font_dict.charstring_type,
decoder->num_locals );
decoder->glyph_width = sub->private_dict.default_width;
decoder->nominal_width = sub->private_dict.nominal_width;
decoder->current_subfont = sub;
Exit:
return error;
}
/* END */