ref: da877c8693f7d0946b8c32634f1cdd82efe31315
dir: /src/cff/cffgload.c/
/****************************************************************************
*
* cffgload.c
*
* OpenType Glyph Loader (body).
*
* Copyright (C) 1996-2022 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/ftstream.h>
#include <freetype/internal/sfnt.h>
#include <freetype/internal/ftcalc.h>
#include <freetype/internal/psaux.h>
#include <freetype/ftoutln.h>
#include <freetype/ftdriver.h>
#include "cffload.h"
#include "cffgload.h"
#include "cfferrs.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 cffgload
FT_LOCAL_DEF( FT_Error )
cff_get_glyph_data( TT_Face face,
FT_UInt glyph_index,
FT_Byte** pointer,
FT_ULong* length )
{
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* For incremental fonts get the character data using the */
/* callback function. */
if ( face->root.internal->incremental_interface )
{
FT_Data data;
FT_Error error =
face->root.internal->incremental_interface->funcs->get_glyph_data(
face->root.internal->incremental_interface->object,
glyph_index, &data );
*pointer = (FT_Byte*)data.pointer;
*length = data.length;
return error;
}
else
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
{
CFF_Font cff = (CFF_Font)(face->extra.data);
return cff_index_access_element( &cff->charstrings_index, glyph_index,
pointer, length );
}
}
FT_LOCAL_DEF( void )
cff_free_glyph_data( TT_Face face,
FT_Byte** pointer,
FT_ULong length )
{
#ifndef FT_CONFIG_OPTION_INCREMENTAL
FT_UNUSED( length );
#endif
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* For incremental fonts get the character data using the */
/* callback function. */
if ( face->root.internal->incremental_interface )
{
FT_Data data;
data.pointer = *pointer;
data.length = (FT_UInt)length;
face->root.internal->incremental_interface->funcs->free_glyph_data(
face->root.internal->incremental_interface->object, &data );
}
else
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
{
CFF_Font cff = (CFF_Font)(face->extra.data);
cff_index_forget_element( &cff->charstrings_index, pointer );
}
}
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/********** *********/
/********** *********/
/********** COMPUTE THE MAXIMUM ADVANCE WIDTH *********/
/********** *********/
/********** The following code is in charge of computing *********/
/********** the maximum advance width of the font. It *********/
/********** quickly processes each glyph charstring to *********/
/********** extract the value from either a `sbw' or `seac' *********/
/********** operator. *********/
/********** *********/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
#if 0 /* unused until we support pure CFF fonts */
FT_LOCAL_DEF( FT_Error )
cff_compute_max_advance( TT_Face face,
FT_Int* max_advance )
{
FT_Error error = FT_Err_Ok;
CFF_Decoder decoder;
FT_Int glyph_index;
CFF_Font cff = (CFF_Font)face->other;
PSAux_Service psaux = (PSAux_Service)face->psaux;
const CFF_Decoder_Funcs decoder_funcs = psaux->cff_decoder_funcs;
*max_advance = 0;
/* Initialize load decoder */
decoder_funcs->init( &decoder, face, 0, 0, 0, 0, 0, 0 );
decoder.builder.metrics_only = 1;
decoder.builder.load_points = 0;
/* For each glyph, parse the glyph charstring and extract */
/* the advance width. */
for ( glyph_index = 0; glyph_index < face->root.num_glyphs;
glyph_index++ )
{
FT_Byte* charstring;
FT_ULong charstring_len;
/* now get load the unscaled outline */
error = cff_get_glyph_data( face, glyph_index,
&charstring, &charstring_len );
if ( !error )
{
error = decoder_funcs->prepare( &decoder, size, glyph_index );
if ( !error )
error = decoder_funcs->parse_charstrings_old( &decoder,
charstring,
charstring_len,
0 );
cff_free_glyph_data( face, &charstring, &charstring_len );
}
/* ignore the error if one has occurred -- skip to next glyph */
error = FT_Err_Ok;
}
*max_advance = decoder.builder.advance.x;
return FT_Err_Ok;
}
#endif /* 0 */
FT_LOCAL_DEF( FT_Error )
cff_slot_load( CFF_GlyphSlot glyph,
CFF_Size size,
FT_UInt glyph_index,
FT_Int32 load_flags )
{
FT_Error error;
CFF_Decoder decoder;
PS_Decoder psdecoder;
TT_Face face = (TT_Face)glyph->root.face;
FT_Bool hinting, scaled, force_scaling;
CFF_Font cff = (CFF_Font)face->extra.data;
PSAux_Service psaux = (PSAux_Service)face->psaux;
const CFF_Decoder_Funcs decoder_funcs = psaux->cff_decoder_funcs;
FT_Matrix font_matrix;
FT_Vector font_offset;
force_scaling = FALSE;
/* in a CID-keyed font, consider `glyph_index' as a CID and map */
/* it immediately to the real glyph_index -- if it isn't a */
/* subsetted font, glyph_indices and CIDs are identical, though */
if ( cff->top_font.font_dict.cid_registry != 0xFFFFU &&
cff->charset.cids )
{
/* don't handle CID 0 (.notdef) which is directly mapped to GID 0 */
if ( glyph_index != 0 )
{
glyph_index = cff_charset_cid_to_gindex( &cff->charset,
glyph_index );
if ( glyph_index == 0 )
return FT_THROW( Invalid_Argument );
}
}
else if ( glyph_index >= cff->num_glyphs )
return FT_THROW( Invalid_Argument );
if ( load_flags & FT_LOAD_NO_RECURSE )
load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING;
glyph->x_scale = 0x10000L;
glyph->y_scale = 0x10000L;
if ( size )
{
glyph->x_scale = size->root.metrics.x_scale;
glyph->y_scale = size->root.metrics.y_scale;
}
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
/* try to load embedded bitmap if any */
/* */
/* XXX: The convention should be emphasized in */
/* the documents because it can be confusing. */
if ( size )
{
CFF_Face cff_face = (CFF_Face)size->root.face;
SFNT_Service sfnt = (SFNT_Service)cff_face->sfnt;
FT_Stream stream = cff_face->root.stream;
if ( size->strike_index != 0xFFFFFFFFUL &&
sfnt->load_eblc &&
( load_flags & FT_LOAD_NO_BITMAP ) == 0 )
{
TT_SBit_MetricsRec metrics;
error = sfnt->load_sbit_image( face,
size->strike_index,
glyph_index,
(FT_UInt)load_flags,
stream,
&glyph->root.bitmap,
&metrics );
if ( !error )
{
FT_Bool has_vertical_info;
FT_UShort advance;
FT_Short dummy;
glyph->root.outline.n_points = 0;
glyph->root.outline.n_contours = 0;
glyph->root.metrics.width = (FT_Pos)metrics.width * 64;
glyph->root.metrics.height = (FT_Pos)metrics.height * 64;
glyph->root.metrics.horiBearingX = (FT_Pos)metrics.horiBearingX * 64;
glyph->root.metrics.horiBearingY = (FT_Pos)metrics.horiBearingY * 64;
glyph->root.metrics.horiAdvance = (FT_Pos)metrics.horiAdvance * 64;
glyph->root.metrics.vertBearingX = (FT_Pos)metrics.vertBearingX * 64;
glyph->root.metrics.vertBearingY = (FT_Pos)metrics.vertBearingY * 64;
glyph->root.metrics.vertAdvance = (FT_Pos)metrics.vertAdvance * 64;
glyph->root.format = FT_GLYPH_FORMAT_BITMAP;
if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
{
glyph->root.bitmap_left = metrics.vertBearingX;
glyph->root.bitmap_top = metrics.vertBearingY;
}
else
{
glyph->root.bitmap_left = metrics.horiBearingX;
glyph->root.bitmap_top = metrics.horiBearingY;
}
/* compute linear advance widths */
(void)( (SFNT_Service)face->sfnt )->get_metrics( face, 0,
glyph_index,
&dummy,
&advance );
glyph->root.linearHoriAdvance = advance;
has_vertical_info = FT_BOOL(
face->vertical_info &&
face->vertical.number_Of_VMetrics > 0 );
/* get the vertical metrics from the vmtx table if we have one */
if ( has_vertical_info )
{
(void)( (SFNT_Service)face->sfnt )->get_metrics( face, 1,
glyph_index,
&dummy,
&advance );
glyph->root.linearVertAdvance = advance;
}
else
{
/* make up vertical ones */
if ( face->os2.version != 0xFFFFU )
glyph->root.linearVertAdvance = (FT_Pos)
( face->os2.sTypoAscender - face->os2.sTypoDescender );
else
glyph->root.linearVertAdvance = (FT_Pos)
( face->horizontal.Ascender - face->horizontal.Descender );
}
return error;
}
}
}
#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
/* return immediately if we only want the embedded bitmaps */
if ( load_flags & FT_LOAD_SBITS_ONLY )
return FT_THROW( Invalid_Argument );
#ifdef FT_CONFIG_OPTION_SVG
/* check for OT-SVG */
if ( ( load_flags & FT_LOAD_COLOR ) &&
( (TT_Face)glyph->root.face )->svg )
{
/*
* We load the SVG document and try to grab the advances from the
* table. For the bearings we rely on the presetting hook to do that.
*/
FT_Short dummy;
FT_UShort advanceX;
FT_UShort advanceY;
SFNT_Service sfnt;
if ( size->root.metrics.x_ppem < 1 ||
size->root.metrics.y_ppem < 1 )
{
error = FT_THROW( Invalid_Size_Handle );
return error;
}
FT_TRACE3(( "Trying to load SVG glyph\n" ));
sfnt = (SFNT_Service)((TT_Face)glyph->root.face)->sfnt;
error = sfnt->load_svg_doc( (FT_GlyphSlot)glyph, glyph_index );
if ( !error )
{
FT_TRACE3(( "Successfully loaded SVG glyph\n" ));
glyph->root.format = FT_GLYPH_FORMAT_SVG;
/*
* If horizontal or vertical advances are not present in the table,
* this is a problem with the font since the standard requires them.
* However, we are graceful and calculate the values by ourselves
* for the vertical case.
*/
sfnt->get_metrics( face,
FALSE,
glyph_index,
&dummy,
&advanceX );
sfnt->get_metrics( face,
TRUE,
glyph_index,
&dummy,
&advanceY );
advanceX =
(FT_UShort)FT_MulDiv( advanceX,
glyph->root.face->size->metrics.x_ppem,
glyph->root.face->units_per_EM );
advanceY =
(FT_UShort)FT_MulDiv( advanceY,
glyph->root.face->size->metrics.y_ppem,
glyph->root.face->units_per_EM );
glyph->root.metrics.horiAdvance = advanceX << 6;
glyph->root.metrics.vertAdvance = advanceY << 6;
return error;
}
FT_TRACE3(( "Failed to load SVG glyph\n" ));
}
#endif /* FT_CONFIG_OPTION_SVG */
/* if we have a CID subfont, use its matrix (which has already */
/* been multiplied with the root matrix) */
/* this scaling is only relevant if the PS hinter isn't active */
if ( cff->num_subfonts )
{
FT_Long top_upm, sub_upm;
FT_Byte fd_index = cff_fd_select_get( &cff->fd_select,
glyph_index );
if ( fd_index >= cff->num_subfonts )
fd_index = (FT_Byte)( cff->num_subfonts - 1 );
top_upm = (FT_Long)cff->top_font.font_dict.units_per_em;
sub_upm = (FT_Long)cff->subfonts[fd_index]->font_dict.units_per_em;
font_matrix = cff->subfonts[fd_index]->font_dict.font_matrix;
font_offset = cff->subfonts[fd_index]->font_dict.font_offset;
if ( top_upm != sub_upm )
{
glyph->x_scale = FT_MulDiv( glyph->x_scale, top_upm, sub_upm );
glyph->y_scale = FT_MulDiv( glyph->y_scale, top_upm, sub_upm );
force_scaling = TRUE;
}
}
else
{
font_matrix = cff->top_font.font_dict.font_matrix;
font_offset = cff->top_font.font_dict.font_offset;
}
glyph->root.outline.n_points = 0;
glyph->root.outline.n_contours = 0;
/* top-level code ensures that FT_LOAD_NO_HINTING is set */
/* if FT_LOAD_NO_SCALE is active */
hinting = FT_BOOL( ( load_flags & FT_LOAD_NO_HINTING ) == 0 );
scaled = FT_BOOL( ( load_flags & FT_LOAD_NO_SCALE ) == 0 );
glyph->hint = hinting;
glyph->scaled = scaled;
glyph->root.format = FT_GLYPH_FORMAT_OUTLINE; /* by default */
{
#ifdef CFF_CONFIG_OPTION_OLD_ENGINE
PS_Driver driver = (PS_Driver)FT_FACE_DRIVER( face );
#endif
FT_Byte* charstring;
FT_ULong charstring_len;
decoder_funcs->init( &decoder, face, size, glyph, hinting,
FT_LOAD_TARGET_MODE( load_flags ),
cff_get_glyph_data,
cff_free_glyph_data );
/* this is for pure CFFs */
if ( load_flags & FT_LOAD_ADVANCE_ONLY )
decoder.width_only = TRUE;
decoder.builder.no_recurse =
FT_BOOL( load_flags & FT_LOAD_NO_RECURSE );
/* now load the unscaled outline */
error = cff_get_glyph_data( face, glyph_index,
&charstring, &charstring_len );
if ( error )
goto Glyph_Build_Finished;
error = decoder_funcs->prepare( &decoder, size, glyph_index );
if ( error )
goto Glyph_Build_Finished;
#ifdef CFF_CONFIG_OPTION_OLD_ENGINE
/* choose which CFF renderer to use */
if ( driver->hinting_engine == FT_HINTING_FREETYPE )
error = decoder_funcs->parse_charstrings_old( &decoder,
charstring,
charstring_len,
0 );
else
#endif
{
psaux->ps_decoder_init( &psdecoder, &decoder, FALSE );
error = decoder_funcs->parse_charstrings( &psdecoder,
charstring,
charstring_len );
/* Adobe's engine uses 16.16 numbers everywhere; */
/* as a consequence, glyphs larger than 2000ppem get rejected */
if ( FT_ERR_EQ( error, Glyph_Too_Big ) )
{
/* this time, we retry unhinted and scale up the glyph later on */
/* (the engine uses and sets the hardcoded value 0x10000 / 64 = */
/* 0x400 for both `x_scale' and `y_scale' in this case) */
hinting = FALSE;
force_scaling = TRUE;
glyph->hint = hinting;
error = decoder_funcs->parse_charstrings( &psdecoder,
charstring,
charstring_len );
}
}
cff_free_glyph_data( face, &charstring, charstring_len );
if ( error )
goto Glyph_Build_Finished;
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* Control data and length may not be available for incremental */
/* fonts. */
if ( face->root.internal->incremental_interface )
{
glyph->root.control_data = NULL;
glyph->root.control_len = 0;
}
else
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
/* We set control_data and control_len if charstrings is loaded. */
/* See how charstring loads at cff_index_access_element() in */
/* cffload.c. */
{
CFF_Index csindex = &cff->charstrings_index;
if ( csindex->offsets )
{
glyph->root.control_data = csindex->bytes +
csindex->offsets[glyph_index] - 1;
glyph->root.control_len = (FT_Long)charstring_len;
}
}
Glyph_Build_Finished:
/* save new glyph tables, if no error */
if ( !error )
decoder.builder.funcs.done( &decoder.builder );
/* XXX: anything to do for broken glyph entry? */
}
#ifdef FT_CONFIG_OPTION_INCREMENTAL
/* Incremental fonts can optionally override the metrics. */
if ( !error &&
face->root.internal->incremental_interface &&
face->root.internal->incremental_interface->funcs->get_glyph_metrics )
{
FT_Incremental_MetricsRec metrics;
metrics.bearing_x = decoder.builder.left_bearing.x;
metrics.bearing_y = 0;
metrics.advance = decoder.builder.advance.x;
metrics.advance_v = decoder.builder.advance.y;
error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
face->root.internal->incremental_interface->object,
glyph_index, FALSE, &metrics );
decoder.builder.left_bearing.x = metrics.bearing_x;
decoder.builder.advance.x = metrics.advance;
decoder.builder.advance.y = metrics.advance_v;
}
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
if ( !error )
{
/* Now, set the metrics -- this is rather simple, as */
/* the left side bearing is the xMin, and the top side */
/* bearing the yMax. */
/* For composite glyphs, return only left side bearing and */
/* advance width. */
if ( load_flags & FT_LOAD_NO_RECURSE )
{
FT_Slot_Internal internal = glyph->root.internal;
glyph->root.metrics.horiBearingX = decoder.builder.left_bearing.x;
glyph->root.metrics.horiAdvance = decoder.glyph_width;
internal->glyph_matrix = font_matrix;
internal->glyph_delta = font_offset;
internal->glyph_transformed = 1;
}
else
{
FT_BBox cbox;
FT_Glyph_Metrics* metrics = &glyph->root.metrics;
FT_Bool has_vertical_info;
if ( face->horizontal.number_Of_HMetrics )
{
FT_Short horiBearingX = 0;
FT_UShort horiAdvance = 0;
( (SFNT_Service)face->sfnt )->get_metrics( face, 0,
glyph_index,
&horiBearingX,
&horiAdvance );
metrics->horiAdvance = horiAdvance;
metrics->horiBearingX = horiBearingX;
glyph->root.linearHoriAdvance = horiAdvance;
}
else
{
/* copy the _unscaled_ advance width */
metrics->horiAdvance = decoder.glyph_width;
glyph->root.linearHoriAdvance = decoder.glyph_width;
}
glyph->root.internal->glyph_transformed = 0;
has_vertical_info = FT_BOOL( face->vertical_info &&
face->vertical.number_Of_VMetrics > 0 );
/* get the vertical metrics from the vmtx table if we have one */
if ( has_vertical_info )
{
FT_Short vertBearingY = 0;
FT_UShort vertAdvance = 0;
( (SFNT_Service)face->sfnt )->get_metrics( face, 1,
glyph_index,
&vertBearingY,
&vertAdvance );
metrics->vertBearingY = vertBearingY;
metrics->vertAdvance = vertAdvance;
}
else
{
/* make up vertical ones */
if ( face->os2.version != 0xFFFFU )
metrics->vertAdvance = (FT_Pos)( face->os2.sTypoAscender -
face->os2.sTypoDescender );
else
metrics->vertAdvance = (FT_Pos)( face->horizontal.Ascender -
face->horizontal.Descender );
}
glyph->root.linearVertAdvance = metrics->vertAdvance;
glyph->root.format = FT_GLYPH_FORMAT_OUTLINE;
glyph->root.outline.flags = 0;
if ( size && size->root.metrics.y_ppem < 24 )
glyph->root.outline.flags |= FT_OUTLINE_HIGH_PRECISION;
glyph->root.outline.flags |= FT_OUTLINE_REVERSE_FILL;
/* apply the font matrix, if any */
if ( font_matrix.xx != 0x10000L || font_matrix.yy != 0x10000L ||
font_matrix.xy != 0 || font_matrix.yx != 0 )
{
FT_Outline_Transform( &glyph->root.outline, &font_matrix );
metrics->horiAdvance = FT_MulFix( metrics->horiAdvance,
font_matrix.xx );
metrics->vertAdvance = FT_MulFix( metrics->vertAdvance,
font_matrix.yy );
}
if ( font_offset.x || font_offset.y )
{
FT_Outline_Translate( &glyph->root.outline,
font_offset.x,
font_offset.y );
metrics->horiAdvance += font_offset.x;
metrics->vertAdvance += font_offset.y;
}
if ( ( load_flags & FT_LOAD_NO_SCALE ) == 0 || force_scaling )
{
/* scale the outline and the metrics */
FT_Int n;
FT_Outline* cur = &glyph->root.outline;
FT_Vector* vec = cur->points;
FT_Fixed x_scale = glyph->x_scale;
FT_Fixed y_scale = glyph->y_scale;
/* First of all, scale the points */
if ( !hinting || !decoder.builder.hints_funcs )
for ( n = cur->n_points; n > 0; n--, vec++ )
{
vec->x = FT_MulFix( vec->x, x_scale );
vec->y = FT_MulFix( vec->y, y_scale );
}
/* Then scale the metrics */
metrics->horiAdvance = FT_MulFix( metrics->horiAdvance, x_scale );
metrics->vertAdvance = FT_MulFix( metrics->vertAdvance, y_scale );
}
/* compute the other metrics */
FT_Outline_Get_CBox( &glyph->root.outline, &cbox );
metrics->width = cbox.xMax - cbox.xMin;
metrics->height = cbox.yMax - cbox.yMin;
metrics->horiBearingX = cbox.xMin;
metrics->horiBearingY = cbox.yMax;
if ( has_vertical_info )
{
metrics->vertBearingX = metrics->horiBearingX -
metrics->horiAdvance / 2;
metrics->vertBearingY = FT_MulFix( metrics->vertBearingY,
glyph->y_scale );
}
else
{
if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
ft_synthesize_vertical_metrics( metrics,
metrics->vertAdvance );
}
}
}
return error;
}
/* END */