ref: 772a5e5ddd2861e9b27de745699670e746442e0e
dir: /include/internal/sfnt.h/
/***************************************************************************/
/* */
/* sfnt.h */
/* */
/* High-level `sfnt' driver interface (specification). */
/* */
/* Copyright 1996-2015 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. */
/* */
/***************************************************************************/
#ifndef __SFNT_H__
#define __SFNT_H__
#include <ft2build.h>
#include FT_INTERNAL_DRIVER_H
#include FT_INTERNAL_TRUETYPE_TYPES_H
FT_BEGIN_HEADER
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Init_Face_Func */
/* */
/* <Description> */
/* First part of the SFNT face object initialization. This finds */
/* the face in a SFNT file or collection, and load its format tag in */
/* face->format_tag. */
/* */
/* <Input> */
/* stream :: The input stream. */
/* */
/* face :: A handle to the target face object. */
/* */
/* face_index :: The index of the TrueType font, if we are opening a */
/* collection. */
/* */
/* num_params :: The number of additional parameters. */
/* */
/* params :: Optional additional parameters. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <Note> */
/* The stream cursor must be at the font file's origin. */
/* */
/* This function recognizes fonts embedded in a `TrueType */
/* collection'. */
/* */
/* Once the format tag has been validated by the font driver, it */
/* should then call the TT_Load_Face_Func() callback to read the rest */
/* of the SFNT tables in the object. */
/* */
typedef FT_Error
(*TT_Init_Face_Func)( FT_Stream stream,
TT_Face face,
FT_Int face_index,
FT_Int num_params,
FT_Parameter* params );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Load_Face_Func */
/* */
/* <Description> */
/* Second part of the SFNT face object initialization. This loads */
/* the common SFNT tables (head, OS/2, maxp, metrics, etc.) in the */
/* face object. */
/* */
/* <Input> */
/* stream :: The input stream. */
/* */
/* face :: A handle to the target face object. */
/* */
/* face_index :: The index of the TrueType font, if we are opening a */
/* collection. */
/* */
/* num_params :: The number of additional parameters. */
/* */
/* params :: Optional additional parameters. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <Note> */
/* This function must be called after TT_Init_Face_Func(). */
/* */
typedef FT_Error
(*TT_Load_Face_Func)( FT_Stream stream,
TT_Face face,
FT_Int face_index,
FT_Int num_params,
FT_Parameter* params );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Done_Face_Func */
/* */
/* <Description> */
/* A callback used to delete the common SFNT data from a face. */
/* */
/* <Input> */
/* face :: A handle to the target face object. */
/* */
/* <Note> */
/* This function does NOT destroy the face object. */
/* */
typedef void
(*TT_Done_Face_Func)( TT_Face face );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Load_Any_Func */
/* */
/* <Description> */
/* Load any font table into client memory. */
/* */
/* <Input> */
/* face :: The face object to look for. */
/* */
/* tag :: The tag of table to load. Use the value 0 if you want */
/* to access the whole font file, else set this parameter */
/* to a valid TrueType table tag that you can forge with */
/* the MAKE_TT_TAG macro. */
/* */
/* offset :: The starting offset in the table (or the file if */
/* tag == 0). */
/* */
/* length :: The address of the decision variable: */
/* */
/* If length == NULL: */
/* Loads the whole table. Returns an error if */
/* `offset' == 0! */
/* */
/* If *length == 0: */
/* Exits immediately; returning the length of the given */
/* table or of the font file, depending on the value of */
/* `tag'. */
/* */
/* If *length != 0: */
/* Loads the next `length' bytes of table or font, */
/* starting at offset `offset' (in table or font too). */
/* */
/* <Output> */
/* buffer :: The address of target buffer. */
/* */
/* <Return> */
/* TrueType error code. 0 means success. */
/* */
typedef FT_Error
(*TT_Load_Any_Func)( TT_Face face,
FT_ULong tag,
FT_Long offset,
FT_Byte *buffer,
FT_ULong* length );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Find_SBit_Image_Func */
/* */
/* <Description> */
/* Check whether an embedded bitmap (an `sbit') exists for a given */
/* glyph, at a given strike. */
/* */
/* <Input> */
/* face :: The target face object. */
/* */
/* glyph_index :: The glyph index. */
/* */
/* strike_index :: The current strike index. */
/* */
/* <Output> */
/* arange :: The SBit range containing the glyph index. */
/* */
/* astrike :: The SBit strike containing the glyph index. */
/* */
/* aglyph_offset :: The offset of the glyph data in `EBDT' table. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. Returns */
/* SFNT_Err_Invalid_Argument if no sbit exists for the requested */
/* glyph. */
/* */
typedef FT_Error
(*TT_Find_SBit_Image_Func)( TT_Face face,
FT_UInt glyph_index,
FT_ULong strike_index,
TT_SBit_Range *arange,
TT_SBit_Strike *astrike,
FT_ULong *aglyph_offset );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Load_SBit_Metrics_Func */
/* */
/* <Description> */
/* Get the big metrics for a given embedded bitmap. */
/* */
/* <Input> */
/* stream :: The input stream. */
/* */
/* range :: The SBit range containing the glyph. */
/* */
/* <Output> */
/* big_metrics :: A big SBit metrics structure for the glyph. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <Note> */
/* The stream cursor must be positioned at the glyph's offset within */
/* the `EBDT' table before the call. */
/* */
/* If the image format uses variable metrics, the stream cursor is */
/* positioned just after the metrics header in the `EBDT' table on */
/* function exit. */
/* */
typedef FT_Error
(*TT_Load_SBit_Metrics_Func)( FT_Stream stream,
TT_SBit_Range range,
TT_SBit_Metrics metrics );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Load_SBit_Image_Func */
/* */
/* <Description> */
/* Load a given glyph sbit image from the font resource. This also */
/* returns its metrics. */
/* */
/* <Input> */
/* face :: */
/* The target face object. */
/* */
/* strike_index :: */
/* The strike index. */
/* */
/* glyph_index :: */
/* The current glyph index. */
/* */
/* load_flags :: */
/* The current load flags. */
/* */
/* stream :: */
/* The input stream. */
/* */
/* <Output> */
/* amap :: */
/* The target pixmap. */
/* */
/* ametrics :: */
/* A big sbit metrics structure for the glyph image. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. Returns an error if no */
/* glyph sbit exists for the index. */
/* */
/* <Note> */
/* The `map.buffer' field is always freed before the glyph is loaded. */
/* */
typedef FT_Error
(*TT_Load_SBit_Image_Func)( TT_Face face,
FT_ULong strike_index,
FT_UInt glyph_index,
FT_UInt load_flags,
FT_Stream stream,
FT_Bitmap *amap,
TT_SBit_MetricsRec *ametrics );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Set_SBit_Strike_Func */
/* */
/* <Description> */
/* Select an sbit strike for a given size request. */
/* */
/* <Input> */
/* face :: The target face object. */
/* */
/* req :: The size request. */
/* */
/* <Output> */
/* astrike_index :: The index of the sbit strike. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. Returns an error if no */
/* sbit strike exists for the selected ppem values. */
/* */
typedef FT_Error
(*TT_Set_SBit_Strike_Func)( TT_Face face,
FT_Size_Request req,
FT_ULong* astrike_index );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Load_Strike_Metrics_Func */
/* */
/* <Description> */
/* Load the metrics of a given strike. */
/* */
/* <Input> */
/* face :: The target face object. */
/* */
/* strike_index :: The strike index. */
/* */
/* <Output> */
/* metrics :: the metrics of the strike. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. Returns an error if no */
/* such sbit strike exists. */
/* */
typedef FT_Error
(*TT_Load_Strike_Metrics_Func)( TT_Face face,
FT_ULong strike_index,
FT_Size_Metrics* metrics );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Get_PS_Name_Func */
/* */
/* <Description> */
/* Get the PostScript glyph name of a glyph. */
/* */
/* <Input> */
/* idx :: The glyph index. */
/* */
/* PSname :: The address of a string pointer. Will be NULL in case */
/* of error, otherwise it is a pointer to the glyph name. */
/* */
/* You must not modify the returned string! */
/* */
/* <Output> */
/* FreeType error code. 0 means success. */
/* */
typedef FT_Error
(*TT_Get_PS_Name_Func)( TT_Face face,
FT_UInt idx,
FT_String** PSname );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Load_Metrics_Func */
/* */
/* <Description> */
/* Load a metrics table, which is a table with a horizontal and a */
/* vertical version. */
/* */
/* <Input> */
/* face :: A handle to the target face object. */
/* */
/* stream :: The input stream. */
/* */
/* vertical :: A boolean flag. If set, load the vertical one. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
typedef FT_Error
(*TT_Load_Metrics_Func)( TT_Face face,
FT_Stream stream,
FT_Bool vertical );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Get_Metrics_Func */
/* */
/* <Description> */
/* Load the horizontal or vertical header in a face object. */
/* */
/* <Input> */
/* face :: A handle to the target face object. */
/* */
/* vertical :: A boolean flag. If set, load vertical metrics. */
/* */
/* gindex :: The glyph index. */
/* */
/* <Output> */
/* abearing :: The horizontal (or vertical) bearing. Set to zero in */
/* case of error. */
/* */
/* aadvance :: The horizontal (or vertical) advance. Set to zero in */
/* case of error. */
/* */
typedef void
(*TT_Get_Metrics_Func)( TT_Face face,
FT_Bool vertical,
FT_UInt gindex,
FT_Short* abearing,
FT_UShort* aadvance );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Load_Table_Func */
/* */
/* <Description> */
/* Load a given TrueType table. */
/* */
/* <Input> */
/* face :: A handle to the target face object. */
/* */
/* stream :: The input stream. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <Note> */
/* The function uses `face->goto_table' to seek the stream to the */
/* start of the table, except while loading the font directory. */
/* */
typedef FT_Error
(*TT_Load_Table_Func)( TT_Face face,
FT_Stream stream );
/*************************************************************************/
/* */
/* <FuncType> */
/* TT_Free_Table_Func */
/* */
/* <Description> */
/* Free a given TrueType table. */
/* */
/* <Input> */
/* face :: A handle to the target face object. */
/* */
typedef void
(*TT_Free_Table_Func)( TT_Face face );
/*
* @functype:
* TT_Face_GetKerningFunc
*
* @description:
* Return the horizontal kerning value between two glyphs.
*
* @input:
* face :: A handle to the source face object.
* left_glyph :: The left glyph index.
* right_glyph :: The right glyph index.
*
* @return:
* The kerning value in font units.
*/
typedef FT_Int
(*TT_Face_GetKerningFunc)( TT_Face face,
FT_UInt left_glyph,
FT_UInt right_glyph );
/*************************************************************************/
/* */
/* <Struct> */
/* SFNT_Interface */
/* */
/* <Description> */
/* This structure holds pointers to the functions used to load and */
/* free the basic tables that are required in a `sfnt' font file. */
/* */
/* <Fields> */
/* Check the various xxx_Func() descriptions for details. */
/* */
typedef struct SFNT_Interface_
{
TT_Loader_GotoTableFunc goto_table;
TT_Init_Face_Func init_face;
TT_Load_Face_Func load_face;
TT_Done_Face_Func done_face;
FT_Module_Requester get_interface;
TT_Load_Any_Func load_any;
/* these functions are called by `load_face' but they can also */
/* be called from external modules, if there is a need to do so */
TT_Load_Table_Func load_head;
TT_Load_Metrics_Func load_hhea;
TT_Load_Table_Func load_cmap;
TT_Load_Table_Func load_maxp;
TT_Load_Table_Func load_os2;
TT_Load_Table_Func load_post;
TT_Load_Table_Func load_name;
TT_Free_Table_Func free_name;
/* this field was called `load_kerning' up to version 2.1.10 */
TT_Load_Table_Func load_kern;
TT_Load_Table_Func load_gasp;
TT_Load_Table_Func load_pclt;
/* see `ttload.h'; this field was called `load_bitmap_header' up to */
/* version 2.1.10 */
TT_Load_Table_Func load_bhed;
TT_Load_SBit_Image_Func load_sbit_image;
/* see `ttpost.h' */
TT_Get_PS_Name_Func get_psname;
TT_Free_Table_Func free_psnames;
/* starting here, the structure differs from version 2.1.7 */
/* this field was introduced in version 2.1.8, named `get_psname' */
TT_Face_GetKerningFunc get_kerning;
/* new elements introduced after version 2.1.10 */
/* load the font directory, i.e., the offset table and */
/* the table directory */
TT_Load_Table_Func load_font_dir;
TT_Load_Metrics_Func load_hmtx;
TT_Load_Table_Func load_eblc;
TT_Free_Table_Func free_eblc;
TT_Set_SBit_Strike_Func set_sbit_strike;
TT_Load_Strike_Metrics_Func load_strike_metrics;
TT_Get_Metrics_Func get_metrics;
} SFNT_Interface;
/* transitional */
typedef SFNT_Interface* SFNT_Service;
#ifndef FT_CONFIG_OPTION_PIC
#define FT_DEFINE_SFNT_INTERFACE( \
class_, \
goto_table_, \
init_face_, \
load_face_, \
done_face_, \
get_interface_, \
load_any_, \
load_head_, \
load_hhea_, \
load_cmap_, \
load_maxp_, \
load_os2_, \
load_post_, \
load_name_, \
free_name_, \
load_kern_, \
load_gasp_, \
load_pclt_, \
load_bhed_, \
load_sbit_image_, \
get_psname_, \
free_psnames_, \
get_kerning_, \
load_font_dir_, \
load_hmtx_, \
load_eblc_, \
free_eblc_, \
set_sbit_strike_, \
load_strike_metrics_, \
get_metrics_ ) \
static const SFNT_Interface class_ = \
{ \
goto_table_, \
init_face_, \
load_face_, \
done_face_, \
get_interface_, \
load_any_, \
load_head_, \
load_hhea_, \
load_cmap_, \
load_maxp_, \
load_os2_, \
load_post_, \
load_name_, \
free_name_, \
load_kern_, \
load_gasp_, \
load_pclt_, \
load_bhed_, \
load_sbit_image_, \
get_psname_, \
free_psnames_, \
get_kerning_, \
load_font_dir_, \
load_hmtx_, \
load_eblc_, \
free_eblc_, \
set_sbit_strike_, \
load_strike_metrics_, \
get_metrics_, \
};
#else /* FT_CONFIG_OPTION_PIC */
#define FT_INTERNAL( a, a_ ) \
clazz->a = a_;
#define FT_DEFINE_SFNT_INTERFACE( \
class_, \
goto_table_, \
init_face_, \
load_face_, \
done_face_, \
get_interface_, \
load_any_, \
load_head_, \
load_hhea_, \
load_cmap_, \
load_maxp_, \
load_os2_, \
load_post_, \
load_name_, \
free_name_, \
load_kern_, \
load_gasp_, \
load_pclt_, \
load_bhed_, \
load_sbit_image_, \
get_psname_, \
free_psnames_, \
get_kerning_, \
load_font_dir_, \
load_hmtx_, \
load_eblc_, \
free_eblc_, \
set_sbit_strike_, \
load_strike_metrics_, \
get_metrics_ ) \
void \
FT_Init_Class_ ## class_( FT_Library library, \
SFNT_Interface* clazz ) \
{ \
FT_UNUSED( library ); \
\
clazz->goto_table = goto_table_; \
clazz->init_face = init_face_; \
clazz->load_face = load_face_; \
clazz->done_face = done_face_; \
clazz->get_interface = get_interface_; \
clazz->load_any = load_any_; \
clazz->load_head = load_head_; \
clazz->load_hhea = load_hhea_; \
clazz->load_cmap = load_cmap_; \
clazz->load_maxp = load_maxp_; \
clazz->load_os2 = load_os2_; \
clazz->load_post = load_post_; \
clazz->load_name = load_name_; \
clazz->free_name = free_name_; \
clazz->load_kern = load_kern_; \
clazz->load_gasp = load_gasp_; \
clazz->load_pclt = load_pclt_; \
clazz->load_bhed = load_bhed_; \
clazz->load_sbit_image = load_sbit_image_; \
clazz->get_psname = get_psname_; \
clazz->free_psnames = free_psnames_; \
clazz->get_kerning = get_kerning_; \
clazz->load_font_dir = load_font_dir_; \
clazz->load_hmtx = load_hmtx_; \
clazz->load_eblc = load_eblc_; \
clazz->free_eblc = free_eblc_; \
clazz->set_sbit_strike = set_sbit_strike_; \
clazz->load_strike_metrics = load_strike_metrics_; \
clazz->get_metrics = get_metrics_; \
}
#endif /* FT_CONFIG_OPTION_PIC */
FT_END_HEADER
#endif /* __SFNT_H__ */
/* END */