ref: 16c691c155a63002fa419abce81d89968891f15d
dir: /src/cff/cffdrivr.c/
/***************************************************************************/
/* */
/* cffdrivr.c */
/* */
/* OpenType font driver implementation (body). */
/* */
/* Copyright 1996-2000 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_STREAM_H
#include FT_INTERNAL_SFNT_H
#include FT_TRUETYPE_NAMES_H
#include FT_INTERNAL_CFF_ERRORS_H
#include FT_SOURCE_FILE(cff,cffdrivr.h)
#include FT_SOURCE_FILE(cff,cffgload.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_cffdriver
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** ****/
/**** F A C E S ****/
/**** ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
#undef PAIR_TAG
#define PAIR_TAG( left, right ) ( ( (FT_ULong)left << 16 ) | \
(FT_ULong)right )
/*************************************************************************/
/* */
/* <Function> */
/* Get_Kerning */
/* */
/* <Description> */
/* A driver method used to return the kerning vector between two */
/* glyphs of the same face. */
/* */
/* <Input> */
/* face :: A handle to the source face object. */
/* */
/* left_glyph :: The index of the left glyph in the kern pair. */
/* */
/* right_glyph :: The index of the right glyph in the kern pair. */
/* */
/* <Output> */
/* kerning :: The kerning vector. This is in font units for */
/* scalable formats, and in pixels for fixed-sizes */
/* formats. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <Note> */
/* Only horizontal layouts (left-to-right & right-to-left) are */
/* supported by this function. Other layouts, or more sophisticated */
/* kernings, are out of scope of this method (the basic driver */
/* interface is meant to be simple). */
/* */
/* They can be implemented by format-specific interfaces. */
/* */
static
FT_Error Get_Kerning( TT_Face face,
FT_UInt left_glyph,
FT_UInt right_glyph,
FT_Vector* kerning )
{
TT_Kern_0_Pair* pair;
if ( !face )
return CFF_Err_Invalid_Face_Handle;
kerning->x = 0;
kerning->y = 0;
if ( face->kern_pairs )
{
/* there are some kerning pairs in this font file! */
FT_ULong search_tag = PAIR_TAG( left_glyph, right_glyph );
FT_Long left, right;
left = 0;
right = face->num_kern_pairs - 1;
while ( left <= right )
{
FT_Int middle = left + ( ( right - left ) >> 1 );
FT_ULong cur_pair;
pair = face->kern_pairs + middle;
cur_pair = PAIR_TAG( pair->left, pair->right );
if ( cur_pair == search_tag )
goto Found;
if ( cur_pair < search_tag )
left = middle + 1;
else
right = middle - 1;
}
}
Exit:
return CFF_Err_Ok;
Found:
kerning->x = pair->value;
goto Exit;
}
#undef PAIR_TAG
/*************************************************************************/
/* */
/* <Function> */
/* Load_Glyph */
/* */
/* <Description> */
/* A driver method used to load a glyph within a given glyph slot. */
/* */
/* <Input> */
/* slot :: A handle to the target slot object where the glyph */
/* will be loaded. */
/* */
/* size :: A handle to the source face size at which the glyph */
/* must be scaled, loaded, etc. */
/* */
/* glyph_index :: The index of the glyph in the font file. */
/* */
/* load_flags :: A flag indicating what to load for this glyph. The */
/* FTLOAD_??? constants can be used to control the */
/* glyph loading process (e.g., whether the outline */
/* should be scaled, whether to load bitmaps or not, */
/* whether to hint the outline, etc). */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
static
FT_Error Load_Glyph( CFF_GlyphSlot slot,
CFF_Size size,
FT_UShort glyph_index,
FT_UInt load_flags )
{
FT_Error error;
if ( !slot )
return CFF_Err_Invalid_Glyph_Handle;
/* check whether we want a scaled outline or bitmap */
if ( !size )
load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING;
if ( load_flags & FT_LOAD_NO_SCALE )
size = NULL;
/* reset the size object if necessary */
if ( size )
{
/* these two object must have the same parent */
if ( size->face != slot->root.face )
return CFF_Err_Invalid_Face_Handle;
}
/* now load the glyph outline if necessary */
error = CFF_Load_Glyph( slot, size, glyph_index, load_flags );
/* force drop-out mode to 2 - irrelevant now */
/* slot->outline.dropout_mode = 2; */
return error;
}
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** ****/
/**** C H A R A C T E R M A P P I N G S ****/
/**** ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* <Function> */
/* Get_Char_Index */
/* */
/* <Description> */
/* Uses a charmap to return a given character code's glyph index. */
/* */
/* <Input> */
/* charmap :: A handle to the source charmap object. */
/* charcode :: The character code. */
/* */
/* <Return> */
/* Glyph index. 0 means `undefined character code'. */
/* */
static
FT_UInt cff_get_char_index( TT_CharMap charmap,
FT_Long charcode )
{
FT_Error error;
CFF_Face face;
TT_CMapTable* cmap;
cmap = &charmap->cmap;
face = (CFF_Face)charmap->root.face;
/* Load table if needed */
if ( !cmap->loaded )
{
SFNT_Interface* sfnt = (SFNT_Interface*)face->sfnt;
error = sfnt->load_charmap( face, cmap, face->root.stream );
if ( error )
return 0;
cmap->loaded = TRUE;
}
return ( cmap->get_index ? cmap->get_index( cmap, charcode ) : 0 );
}
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** ****/
/**** D R I V E R I N T E R F A C E ****/
/**** ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
static
FT_Module_Interface cff_get_interface( CFF_Driver driver,
const char* interface )
{
FT_Module sfnt;
/* we simply pass our request to the `sfnt' module */
sfnt = FT_Get_Module( driver->root.root.library, "sfnt" );
return sfnt ? sfnt->clazz->get_interface( sfnt, interface ) : 0;
}
/* The FT_DriverInterface structure is defined in ftdriver.h. */
FT_CALLBACK_TABLE_DEF
const FT_Driver_Class cff_driver_class =
{
/* begin with the FT_Module_Class fields */
{
ft_module_font_driver | ft_module_driver_scalable,
sizeof( CFF_DriverRec ),
"cff",
0x10000L,
0x20000L,
0, /* module-specific interface */
(FT_Module_Constructor)CFF_Init_Driver,
(FT_Module_Destructor) CFF_Done_Driver,
(FT_Module_Requester) cff_get_interface,
},
/* now the specific driver fields */
sizeof( TT_FaceRec ),
sizeof( FT_SizeRec ),
sizeof( CFF_GlyphSlotRec ),
(FTDriver_initFace) CFF_Init_Face,
(FTDriver_doneFace) CFF_Done_Face,
(FTDriver_initSize) 0,
(FTDriver_doneSize) 0,
(FTDriver_initGlyphSlot)0,
(FTDriver_doneGlyphSlot)0,
(FTDriver_setCharSizes) 0,
(FTDriver_setPixelSizes)0,
(FTDriver_loadGlyph) Load_Glyph,
(FTDriver_getCharIndex) cff_get_char_index,
(FTDriver_getKerning) Get_Kerning,
(FTDriver_attachFile) 0,
(FTDriver_getAdvances) 0
};
#ifdef FT_CONFIG_OPTION_DYNAMIC_DRIVERS
/*************************************************************************/
/* */
/* <Function> */
/* getDriverClass */
/* */
/* <Description> */
/* This function is used when compiling the TrueType driver as a */
/* shared library (`.DLL' or `.so'). It will be used by the */
/* high-level library of FreeType to retrieve the address of the */
/* driver's generic interface. */
/* */
/* It shouldn't be implemented in a static build, as each driver must */
/* have the same function as an exported entry point. */
/* */
/* <Return> */
/* The address of the TrueType's driver generic interface. The */
/* format-specific interface can then be retrieved through the method */
/* interface->get_format_interface. */
/* */
FT_EXPORT_DEF( const FT_Driver_Class* ) getDriverClass( void )
{
return &cff_driver_class;
}
#endif /* CONFIG_OPTION_DYNAMIC_DRIVERS */
/* END */