base.htm

TrueType字库标准文档

<TR>
<TD VALIGN=TOP>0030</TD><TD VALIGN=TOP>HorizRussianMinMaxTable</TD><TD>Offset to MinMax table feature-specific extents</TD></TR>
</TABLE>
&nbsp;&nbsp;


<H4>Example 3: BaseValues Table</H4>
<P>Example 3 extends the BASE table definition for the Cyrillic script described in Examples 1 and 2. It contains two parts:

<UL>
<LI>Example 3A illustrates a fully defined BaseValues table for Cyrillic. The table includes the corresponding BaseCoord table definitions. 
<LI>Example 3B shows two different sets of baseline values that can be defined for each of the four scripts in the sample font.
</UL>

<P>The examples show only horizontal text-layout data, and the font uses 2,048 design units/em.

<H4>Example 3A: BaseValues Table for Cyrillic</H4>
<P>The BaseValues table of Example 3A identifies the default baseline for Cyrillic and specifies coordinate positions for each baseline listed in the BaseTagList shown in Example 1:

<UL>
<LI>The hanging baseline is the default for the Devanagari script, and it has the highest baseline position.
<LI>The ideographic baseline is the default for the Han script, and it has the lowest baseline position.
<LI>The roman baseline is the default for both the Latin and Cyrillic scripts, and its position lies between the hanging and ideographic baselines.
</UL>

<BR>&nbsp;<BR><FONT SIZE=5>Example 3A</font>
<TABLE BGCOLOR="#F0F0F0" WIDTH=480 BORDER=0 CELLPADDING=3>
<THEAD>
<TR>
<TH BGCOLOR="#C0C0C0">Hex Data</TH><TH BGCOLOR="#C0C0C0">Source</TH><TH BGCOLOR="#C0C0C0">Comments</TH></TR>
</THEAD><TBODY>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseValues</STRONG><BR>HorizCyrillicBaseValuesTable</TD><TD VALIGN=BOTTOM>BaseValues table definition for Cyrillic script</TD></TR>
<TR>
<TD VALIGN=TOP>0002</TD><TD VALIGN=TOP>2</TD><TD>DefaultIndex, roman baseline BaselineTag index</TD></TR>
<TR>
<TD VALIGN=TOP>0003</TD><TD VALIGN=TOP>3</TD><TD>BaseCoordCount, equals BaseTagCount</TD></TR>
<TR>
<TD VALIGN=TOP>000A</TD><TD VALIGN=TOP>HorizHangingBaseCoordForCyrl</TD><TD>Offset to BaseCoord[0] table hanging baseline coordinate, order matches order of     BaselineTag array in BaseTagList</TD></TR>
<TR>
<TD VALIGN=TOP>000E</TD><TD VALIGN=TOP>HorizideographicBaseCoordForCyrl</TD><TD>Offset to BaseCoord[1] table ideographic baseline coordinate</TD></TR>
<TR>
<TD VALIGN=TOP>0012</TD><TD VALIGN=TOP>HorizromanBaseCoordForCyrl</TD><TD>Offset to BaseCoord[2] table roman baseline coordinate<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizHangingBaseCoordForCyrl</TD><TD VALIGN=BOTTOM>BaseCoord table definition</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>BaseCoordFormat design units only</TD></TR>
<TR>
<TD VALIGN=TOP>05DC</TD><TD VALIGN=TOP>1500</TD><TD>Coordinate Y value, in design units<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizideographicBaseCoordForCyrl</TD><TD VALIGN=BOTTOM>BaseCoord table definition</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>BaseCoordFormat design units only</TD></TR>
<TR>
<TD VALIGN=TOP>FEE0</TD><TD VALIGN=TOP>-288</TD><TD>Coordinate Y value, in design units<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizromanBaseCoordinateForCyrl</TD><TD VALIGN=BOTTOM>BaseCoord table definition</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>BaseCoordFormat, design units only</TD></TR>
<TR>
<TD VALIGN=TOP>0000</TD><TD VALIGN=TOP>0</TD><TD>Coordinate, Y value, in design units</TD></TR>
</TABLE>
&nbsp;&nbsp;


<H4>Example 3B: Baseline Values for Four Scripts</H4>
<P>Example 3B shows two tables that contain baseline values for each of the four scripts in the sample font described in Example 1:

<UL>
<LI>The first table shows what might happen if the baseline values in all four scripts are designed consistently. Their respective BaseValues tables list identical baseline values with the roman baseline positioned at a Y value of zero (0), the ideographic baseline at 1500, and the hanging baseline at -288.
<LI>The second table shows what might happen if the baseline values in the scripts are designed differently with the default baseline for each script at the zero (0) coordinate.
</UL>

<P>Either method of assigning baseline values can be used in the BASE table.

<BR>&nbsp;<BR><FONT SIZE=5>Example 3B: Identical baseline values</font>
<TABLE BGCOLOR="#F0F0F0" WIDTH=480 BORDER=0 CELLPADDING=3>
<THEAD>
<TR>
<TH BGCOLOR="#C0C0C0">Baseline type</TH><TH BGCOLOR="#C0C0C0">Han</TH><TH BGCOLOR="#C0C0C0">Latin</TH><TH BGCOLOR="#C0C0C0">Cyrillic</TH><TH BGCOLOR="#C0C0C0">Devanagari</TH></TR>
</THEAD><TBODY>	
<TR>
<TD VALIGN=TOP>hanging</TD><TD VALIGN=TOP>1500</TD><TD VALIGN=TOP>1500</TD><TD VALIGN=TOP>1500</TD><TD VALIGN=TOP>1500</TD></TR>
<TR>	
<TD VALIGN=TOP>roman</TD><TD VALIGN=TOP>0</TD><TD VALIGN=TOP>0</TD><TD VALIGN=TOP>0</TD><TD VALIGN=TOP>0</TD></TR>
<TR>	
<TD VALIGN=TOP>ideographic</TD><TD VALIGN=TOP>-288</TD><TD VALIGN=TOP>-288</TD><TD VALIGN=TOP>-288</TD><TD VALIGN=TOP>-288</TD></TR>
</TABLE>
&nbsp;&nbsp;


<BR>&nbsp;<BR><FONT SIZE=5>Example 3B: Assigned baseline values with default baselines at 0</font>	
<TABLE BGCOLOR="#F0F0F0" WIDTH=480 BORDER=0 CELLPADDING=3>
<THEAD>
<TR>
<TH BGCOLOR="#C0C0C0">Baseline type</TH><TH BGCOLOR="#C0C0C0">Han</TH><TH BGCOLOR="#C0C0C0">Latin</TH><TH BGCOLOR="#C0C0C0">Cyrillic</TH><TH BGCOLOR="#C0C0C0">Devanagari</TH></TR>
</THEAD><TBODY>	
<TR>
<TD VALIGN=TOP>hanging</TD><TD VALIGN=TOP>1788</TD><TD VALIGN=TOP>1500</TD><TD VALIGN=TOP>1500</TD><TD VALIGN=TOP>0</TD></TR>
<TR>	
<TD VALIGN=TOP>roman</TD><TD VALIGN=TOP>288</TD><TD VALIGN=TOP>0</TD><TD VALIGN=TOP>0</TD><TD VALIGN=TOP>-1500</TD></TR>
<TR>	
<TD VALIGN=TOP>ideographic</TD><TD VALIGN=TOP>0</TD><TD VALIGN=TOP>-288</TD><TD VALIGN=TOP>-288</TD><TD VALIGN=TOP>-1788</TD></TR>
</TABLE>
&nbsp;&nbsp;

	
<H4>Example 4: MinMax Table and FeatMinMaxRecord</H4>
<P>Example 4 shows MinMax table and FeatMinMaxRecord definitions for the same Cyrillic script described in the previous example. It contains two parts:

<UL>
<LI>Example 4A defines tables with different script, language system, and feature extents.
<LI>Example 4B shows these same table definitions written when the language system extents match the script extents, but an obscure feature of the language system requires feature-specific extents if that feature is implemented.
</UL>

<P>The examples show only horizontal text-layout data, and the font uses 2,048 design units/em.

<H4>Example 4A: Min/Max Extents For Cyrillic Script, Russian Language, and Russian Feature</H4>
<P>Example 4A shows two MinMax tables and a FeatMinMaxRecord for the Cyrillic script, along with sample BaseCoord tables. Only the MinCoord extent data is included.

<P>The DefaultMinMax table defines the default minimum and maximum extents for the Cyrillic script. Another MinMax table defines language-specific min/max extents for the Russian language system to accommodate the height and width of certain glyphs used in Russian. Also, a FeatMinMaxRecord defines min/max extents for a single feature in the Russian language system that substitutes a tall integral math symbol when required. 

<BR>&nbsp;<BR><FONT SIZE=5>Example 4A</font>
<TABLE BGCOLOR="#F0F0F0" WIDTH=480 BORDER=0 CELLPADDING=3>
<THEAD>
<TR>
<TH BGCOLOR="#C0C0C0">Hex Data</TH><TH BGCOLOR="#C0C0C0">Source</TH><TH BGCOLOR="#C0C0C0">Comments</TH></TR>
</THEAD><TBODY>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>MinMax</STRONG><BR>HorizCyrillicDefaultMinMaxTable</TD><TD VALIGN=BOTTOM>DefaultMinMax table definition, Cyrillic script</TD></TR>
<TR>
<TD VALIGN=TOP>0006</TD><TD VALIGN=TOP>HorizCyrillicMinCoordTable</TD><TD>MinCoord offset to BaseCoord table</TD></TR>
<TR>
<TD VALIGN=TOP>000A</TD><TD VALIGN=TOP>HorizCyrillicMaxCoordTable</TD><TD>MaxCoord offset to BaseCoord table</TD></TR>
<TR>
<TD VALIGN=TOP>0000</TD><TD VALIGN=TOP>0</TD><TD>FeatMinMaxCount no default feature extents<BR>FeatMinMaxRecord[], no FeatMinMaxRecords<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizCyrillicMinCoordTable</TD><TD VALIGN=BOTTOM>BaseCoord table definition, default Cyrillic Min 
extent coordinate</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>BaseCoordFormat, design units only</TD></TR>
<TR>
<TD VALIGN=TOP>FF38</TD><TD VALIGN=TOP>-200</TD><TD>Coordinate Y value, in design units<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizCyrillicMaxCoordTable</TD><TD VALIGN=BOTTOM>BaseCoord table definition default Cyrillic Max 
extent coordinate</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>BaseCoordFormat, design units only</TD></TR>
<TR>
<TD VALIGN=TOP>0674</TD><TD VALIGN=TOP>1652</TD><TD>Coordinate Y value, in design units<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>MinMax</STRONG><BR>HorizRussianMinMaxTable</TD><TD VALIGN=BOTTOM>MinMax table definition Russian language extents</TD></TR>
<TR>
<TD VALIGN=TOP>000E</TD><TD VALIGN=TOP>HorizRussianLangSysMinCoordTable</TD><TD>MinCoord Offset to BaseCoord table</TD></TR>
<TR>
<TD VALIGN=TOP>0012</TD><TD VALIGN=TOP>HorizRussianLangSysMaxCoordTable</TD><TD>MaxCoord Offset to BaseCoord table</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>FeatMinMaxCount<BR>FeatMinMaxRecord[0] in alphabetical order</TD></TR>
<TR> 
<TD VALIGN=TOP>696E7467</TD><TD VALIGN=TOP>&quot;intg&quot;</TD><TD>FeatureTableTag integral math symbol Feature must be same as Tag in FeatureList</TD></TR>
<TR>
<TD VALIGN=TOP>0016</TD><TD VALIGN=TOP>HorizRussianFeatureMinCoordTable</TD><TD>MinCoord Offset to BaseCoord table</TD></TR>
<TR>
<TD VALIGN=TOP>001A</TD><TD VALIGN=TOP>HorizRussianFeatureMaxCoordTable</TD><TD>MaxCoord Offset to BaseCoord table<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizRussianLangSysMinCoordTable</TD><TD VALIGN=BOTTOM>BaseCoord table definition Russian language min extent coordinate</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>BaseCoordFormat design units only</TD></TR>
<TR>
<TD VALIGN=TOP>FF08</TD><TD VALIGN=TOP>-248</TD><TD>Coordinate Y value, in design units, increased Min extent beyond default Cyrillic min extent<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizRussianLangSysMaxCoordTable</TD><TD VALIGN=BOTTOM>BaseCoord table definition Russian language feature Max extent coordinate</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>BaseCoordFormat design units only</TD></TR>
<TR>
<TD VALIGN=TOP>06A4</TD><TD VALIGN=TOP>1700</TD><TD>Coordinate Y value, in design units increased max extent beyond default Cyrillic max extent<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizRussianFeatureMinCoordTable</TD><TD VALIGN=BOTTOM>BaseCoord table definition Russian language Min 
extent coordinate</TD></TR>
<TR>
<TD VALIGN=TOP>0001</TD><TD VALIGN=TOP>1</TD><TD>BaseCoordFormat Design Units Only</TD></TR>
<TR>
<TD VALIGN=TOP>FED8</TD><TD VALIGN=TOP>-296</TD><TD>Coordinate Y value, in design units, increased Min extent beyond default Cyrillic script and Russian language min extents<HR></TD></TR>
<TR>
<TD VALIGN=TOP>&nbsp;</TD><TD VALIGN=TOP><STRONG>BaseCoordFormat1</STRONG><BR>HorizRussianFeatureMaxCoordTable</TD><TD VALIGN=BOTTOM>BaseCoord table definition Russian language feature Max extent coordinate</TD></TR>
<TR>