ft2-truetype_tables.html

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<tr valign=top><td><b>Ascender</b></td><td>
<p>The font's ascender, i.e., the distance from the baseline to the top-most of all glyph points found in the font.</p>
<p>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).</p>
<p>You should use the `sTypoAscender' field of the OS/2 table instead if you want the correct one.</p>
</td></tr>
<tr valign=top><td><b>Descender</b></td><td>
<p>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.</p>
<p>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).</p>
<p>You should use the `sTypoDescender' field of the OS/2 table instead if you want the correct one.</p>
</td></tr>
<tr valign=top><td><b>Line_Gap</b></td><td>
<p>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.</p>
</td></tr>
<tr valign=top><td><b>advance_Height_Max</b></td><td>
<p>This field is the maximum of all advance heights found in the font. It can be used to compute the maximum height of an arbitrary string of text.</p>
</td></tr>
<tr valign=top><td><b>min_Top_Side_Bearing</b></td><td>
<p>The minimum top side bearing of all glyphs within the font.</p>
</td></tr>
<tr valign=top><td><b>min_Bottom_Side_Bearing</b></td><td>
<p>The minimum bottom side bearing of all glyphs within the font.</p>
</td></tr>
<tr valign=top><td><b>yMax_Extent</b></td><td>
<p>The maximum vertical extent (i.e., the `height' of a glyph's bounding box) for all glyphs in the font.</p>
</td></tr>
<tr valign=top><td><b>caret_Slope_Rise</b></td><td>
<p>The rise coefficient of the cursor's slope of the cursor (slope=rise/run).</p>
</td></tr>
<tr valign=top><td><b>caret_Slope_Run</b></td><td>
<p>The run coefficient of the cursor's slope.</p>
</td></tr>
<tr valign=top><td><b>caret_Offset</b></td><td>
<p>The cursor's offset for slanted fonts. This value is `reserved' in vmtx version 1.0.</p>
</td></tr>
<tr valign=top><td><b>Reserved</b></td><td>
<p>8 reserved bytes.</p>
</td></tr>
<tr valign=top><td><b>metric_Data_Format</b></td><td>
<p>Always 0.</p>
</td></tr>
<tr valign=top><td><b>number_Of_HMetrics</b></td><td>
<p>Number of VMetrics entries in the `vmtx' table -- this value can be smaller than the total number of glyphs in the font.</p>
</td></tr>
<tr valign=top><td><b>long_metrics</b></td><td>
<p>A pointer into the `vmtx' table.</p>
</td></tr>
<tr valign=top><td><b>short_metrics</b></td><td>
<p>A pointer into the `vmtx' table.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>note</b></em></td></tr><tr><td>
<p>IMPORTANT: The TT_HoriHeader and TT_VertHeader structures should be identical except for the names of their fields which are different.</p>
<p>This ensures that a single function in the `ttload' module is able to read both the horizontal and vertical headers.</p>
</td></tr></table>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="TT_OS2">TT_OS2</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">struct</span>  TT_OS2_
  {
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  version;                /* 0x0001 - more or 0xFFFF */
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   xAvgCharWidth;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usWeightClass;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usWidthClass;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   fsType;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   ySubscriptXSize;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   ySubscriptYSize;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   ySubscriptXOffset;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   ySubscriptYOffset;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   ySuperscriptXSize;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   ySuperscriptYSize;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   ySuperscriptXOffset;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   ySuperscriptYOffset;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   yStrikeoutSize;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   yStrikeoutPosition;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   sFamilyClass;

    <a href="ft2-basic_types.html#FT_Byte">FT_Byte</a>    panose[10];

    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>   ulUnicodeRange1;        /* Bits 0-31   */
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>   ulUnicodeRange2;        /* Bits 32-63  */
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>   ulUnicodeRange3;        /* Bits 64-95  */
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>   ulUnicodeRange4;        /* Bits 96-127 */

    <a href="ft2-basic_types.html#FT_Char">FT_Char</a>    achVendID[4];

    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  fsSelection;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usFirstCharIndex;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usLastCharIndex;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   sTypoAscender;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   sTypoDescender;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   sTypoLineGap;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usWinAscent;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usWinDescent;

    /* only version 1 tables: */

    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>   ulCodePageRange1;       /* Bits 0-31   */
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>   ulCodePageRange2;       /* Bits 32-63  */

    /* only version 2 tables: */

    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   sxHeight;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>   sCapHeight;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usDefaultChar;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usBreakChar;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  usMaxContext;

  } <b>TT_OS2</b>;

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A structure used to model a TrueType OS/2 table. This is the long table version. All fields comply to the TrueType specification.</p>
<p>Note that we now support old Mac fonts which do not include an OS/2 table. In this case, the `version' field is always set to 0xFFFF.</p>
</td></tr></table><br>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="TT_Postscript">TT_Postscript</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">struct</span>  TT_Postscript_
  {
    <a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a>  FormatType;
    <a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a>  italicAngle;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>  underlinePosition;
    <a href="ft2-basic_types.html#FT_Short">FT_Short</a>  underlineThickness;
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>  isFixedPitch;
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>  minMemType42;
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>  maxMemType42;
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>  minMemType1;
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>  maxMemType1;

    /* Glyph names follow in the file, but we don't   */
    /* load them by default.  See the ttpost.c file.  */

  } <b>TT_Postscript</b>;

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A structure used to model a TrueType Postscript table. All fields comply to the TrueType table. This structure does not reference the Postscript glyph names, which can be nevertheless accessed with the `ttpost' module.</p>
</td></tr></table><br>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="TT_PCLT">TT_PCLT</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">struct</span>  TT_PCLT_
  {
    <a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a>   Version;
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>   FontNumber;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  Pitch;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  xHeight;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  Style;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  TypeFamily;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  CapHeight;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  SymbolSet;
    <a href="ft2-basic_types.html#FT_Char">FT_Char</a>    TypeFace[16];
    <a href="ft2-basic_types.html#FT_Char">FT_Char</a>    CharacterComplement[8];
    <a href="ft2-basic_types.html#FT_Char">FT_Char</a>    FileName[6];
    <a href="ft2-basic_types.html#FT_Char">FT_Char</a>    StrokeWeight;
    <a href="ft2-basic_types.html#FT_Char">FT_Char</a>    WidthType;
    <a href="ft2-basic_types.html#FT_Byte">FT_Byte</a>    SerifStyle;
    <a href="ft2-basic_types.html#FT_Byte">FT_Byte</a>    Reserved;

  } <b>TT_PCLT</b>;

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A structure used to model a TrueType PCLT table. All fields comply to the TrueType table.</p>
</td></tr></table><br>
</td></tr></table><hr width="75%">
<table align=center width="75%"><tr><td>
<h4><a name="TT_MaxProfile">TT_MaxProfile</a></h4>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>

  <span class="keyword">typedef</span> <span class="keyword">struct</span>  TT_MaxProfile_
  {
    <a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a>   version;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  numGlyphs;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxPoints;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxContours;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxCompositePoints;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxCompositeContours;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxZones;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxTwilightPoints;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxStorage;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxFunctionDefs;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxInstructionDefs;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxStackElements;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxSizeOfInstructions;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxComponentElements;
    <a href="ft2-basic_types.html#FT_UShort">FT_UShort</a>  maxComponentDepth;

  } <b>TT_MaxProfile</b>;

</pre></table><br>
<table align=center width="87%"><tr><td>
<p>The maximum profile is a table containing many max values which can be used to pre-allocate arrays. This ensures that no memory allocation occurs during a glyph load.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>fields</b></em></td></tr><tr><td>
<table cellpadding=3>
<tr valign=top><td><b>version</b></td><td>
<p>The version number.</p>
</td></tr>
<tr valign=top><td><b>numGlyphs</b></td><td>
<p>The number of glyphs in this TrueType font.</p>
</td></tr>
<tr valign=top><td><b>maxPoints</b></td><td>
<p>The maximum number of points in a non-composite TrueType glyph. See also the structure element `maxCompositePoints'.</p>
</td></tr>
<tr valign=top><td><b>maxContours</b></td><td>
<p>The maximum number of contours in a non-composite TrueType glyph. See also the structure element `maxCompositeContours'.</p>
</td></tr>
<tr valign=top><td><b>maxCompositePoints</b></td><td>
<p>The maximum number of points in a composite TrueType glyph. See also the structure element `maxPoints'.</p>
</td></tr>
<tr valign=top><td><b>maxCompositeContours</b></td><td>
<p>The maximum number of contours in a composite TrueType glyph. See also the structure element `maxContours'.</p>
</td></tr>
<tr valign=top><td><b>maxZones</b></td><td>
<p>The maximum number of zones used for glyph hinting.</p>
</td></tr>
<tr valign=top><td><b>maxTwilightPoints</b></td><td>