📄 tttables.h
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/***************************************************************************/
/* */
/* tttables.h */
/* */
/* Basic SFNT/TrueType tables definitions and interface */
/* (specification only). */
/* */
/* Copyright 1996-2001, 2002, 2003, 2004, 2005 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 __TTTABLES_H__
#define __TTTABLES_H__
#include "ft2build.h"
#include FT_FREETYPE_H
#ifdef FREETYPE_H
#error "freetype.h of FreeType 1 has been loaded!"
#error "Please fix the directory search order for header files"
#error "so that freetype.h of FreeType 2 is found first."
#endif
FT_BEGIN_HEADER
/*************************************************************************/
/* */
/* <Section> */
/* truetype_tables */
/* */
/* <Title> */
/* TrueType Tables */
/* */
/* <Abstract> */
/* TrueType specific table types and functions. */
/* */
/* <Description> */
/* This section contains the definition of TrueType-specific tables */
/* as well as some routines used to access and process them. */
/* */
/*************************************************************************/
/*************************************************************************/
/* */
/* <Struct> */
/* TT_Header */
/* */
/* <Description> */
/* A structure used to model a TrueType font header table. All */
/* fields follow the TrueType specification. */
/* */
typedef struct TT_Header_
{
FT_Fixed Table_Version;
FT_Fixed Font_Revision;
FT_Long CheckSum_Adjust;
FT_Long Magic_Number;
FT_UShort Flags;
FT_UShort Units_Per_EM;
FT_Long Created [2];
FT_Long Modified[2];
FT_Short xMin;
FT_Short yMin;
FT_Short xMax;
FT_Short yMax;
FT_UShort Mac_Style;
FT_UShort Lowest_Rec_PPEM;
FT_Short Font_Direction;
FT_Short Index_To_Loc_Format;
FT_Short Glyph_Data_Format;
} TT_Header;
/*************************************************************************/
/* */
/* <Struct> */
/* TT_HoriHeader */
/* */
/* <Description> */
/* A structure used to model a TrueType horizontal header, the `hhea' */
/* table, as well as the corresponding horizontal metrics table, */
/* i.e., the `hmtx' table. */
/* */
/* <Fields> */
/* Version :: The table version. */
/* */
/* Ascender :: The font's ascender, i.e., the distance */
/* from the baseline to the top-most of all */
/* glyph points found in the font. */
/* */
/* This value is invalid in many fonts, as */
/* it is usually set by the font designer, */
/* and often reflects only a portion of the */
/* glyphs found in the font (maybe ASCII). */
/* */
/* You should use the `sTypoAscender' field */
/* of the OS/2 table instead if you want */
/* the correct one. */
/* */
/* Descender :: The font's descender, i.e., the distance */
/* from the baseline to the bottom-most of */
/* all glyph points found in the font. It */
/* is negative. */
/* */
/* This value is invalid in many fonts, as */
/* it is usually set by the font designer, */
/* and often reflects only a portion of the */
/* glyphs found in the font (maybe ASCII). */
/* */
/* You should use the `sTypoDescender' */
/* field of the OS/2 table instead if you */
/* want the correct one. */
/* */
/* Line_Gap :: The font's line gap, i.e., the distance */
/* to add to the ascender and descender to */
/* get the BTB, i.e., the */
/* baseline-to-baseline distance for the */
/* font. */
/* */
/* advance_Width_Max :: This field is the maximum of all advance */
/* widths found in the font. It can be */
/* used to compute the maximum width of an */
/* arbitrary string of text. */
/* */
/* min_Left_Side_Bearing :: The minimum left side bearing of all */
/* glyphs within the font. */
/* */
/* min_Right_Side_Bearing :: The minimum right side bearing of all */
/* glyphs within the font. */
/* */
/* xMax_Extent :: The maximum horizontal extent (i.e., the */
/* `width' of a glyph's bounding box) for */
/* all glyphs in the font. */
/* */
/* caret_Slope_Rise :: The rise coefficient of the cursor's */
/* slope of the cursor (slope=rise/run). */
/* */
/* caret_Slope_Run :: The run coefficient of the cursor's */
/* slope. */
/* */
/* Reserved :: 10 reserved bytes. */
/* */
/* metric_Data_Format :: Always 0. */
/* */
/* number_Of_HMetrics :: Number of HMetrics entries in the `hmtx' */
/* table -- this value can be smaller than */
/* the total number of glyphs in the font. */
/* */
/* long_metrics :: A pointer into the `hmtx' table. */
/* */
/* short_metrics :: A pointer into the `hmtx' table. */
/* */
/* <Note> */
/* IMPORTANT: The TT_HoriHeader and TT_VertHeader structures should */
/* be identical except for the names of their fields which */
/* are different. */
/* */
/* This ensures that a single function in the `ttload' */
/* module is able to read both the horizontal and vertical */
/* headers. */
/* */
typedef struct TT_HoriHeader_
{
FT_Fixed Version;
FT_Short Ascender;
FT_Short Descender;
FT_Short Line_Gap;
FT_UShort advance_Width_Max; /* advance width maximum */
FT_Short min_Left_Side_Bearing; /* minimum left-sb */
FT_Short min_Right_Side_Bearing; /* minimum right-sb */
FT_Short xMax_Extent; /* xmax extents */
FT_Short caret_Slope_Rise;
FT_Short caret_Slope_Run;
FT_Short caret_Offset;
FT_Short Reserved[4];
FT_Short metric_Data_Format;
FT_UShort number_Of_HMetrics;
/* The following fields are not defined by the TrueType specification */
/* but they are used to connect the metrics header to the relevant */
/* `HMTX' table. */
void* long_metrics;
void* short_metrics;
} TT_HoriHeader;
/*************************************************************************/
/* */
/* <Struct> */
/* TT_VertHeader */
/* */
/* <Description> */
/* A structure used to model a TrueType vertical header, the `vhea' */
/* table, as well as the corresponding vertical metrics table, i.e., */
/* the `vmtx' table. */
/* */
/* <Fields> */
/* Version :: The table version. */
/* */
/* Ascender :: The font's ascender, i.e., the distance */
/* from the baseline to the top-most of */
/* all glyph points found in the font. */
/* */
/* This value is invalid in many fonts, as */
/* it is usually set by the font designer, */
/* and often reflects only a portion of */
/* the glyphs found in the font (maybe */
/* ASCII). */
/* */
/* You should use the `sTypoAscender' */
/* field of the OS/2 table instead if you */
/* want the correct one. */
/* */
/* Descender :: The font's descender, i.e., the */
/* distance from the baseline to the */
/* bottom-most of all glyph points found */
/* in the font. It is negative. */
/* */
/* This value is invalid in many fonts, as */
/* it is usually set by the font designer, */
/* and often reflects only a portion of */
/* the glyphs found in the font (maybe */
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