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.
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 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_Height_Max
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.
min_Top_Side_Bearing
The minimum top side bearing of all glyphs within
the font.
min_Bottom_Side_Bearing
The minimum bottom side bearing of all glyphs
within the font.
yMax_Extent
The maximum vertical extent (i.e., the `height'
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.
caret_Offset
The cursor's offset for slanted fonts. This value
is `reserved' in vmtx version 1.0.
Reserved
8 reserved bytes.
metric_Data_Format
Always 0.
number_Of_HMetrics
Number of VMetrics entries in the `vmtx' table --
this value can be smaller than the total number
of glyphs in the font.
long_metrics
A pointer into the `vmtx' table.
short_metrics
A pointer into the `vmtx' 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.
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.
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.
fields
version
The version number.
numGlyphs
The number of glyphs in this TrueType font.
maxPoints
The maximum number of points in a non-composite
TrueType glyph. See also the structure element
`maxCompositePoints'.
maxContours
The maximum number of contours in a non-composite
TrueType glyph. See also the structure element
`maxCompositeContours'.
maxCompositePoints
The maximum number of points in a composite
TrueType glyph. See also the structure element
`maxPoints'.
maxCompositeContours
The maximum number of contours in a composite
TrueType glyph. See also the structure element
`maxContours'.
maxZones
The maximum number of zones used for glyph
hinting.
maxTwilightPoints
The maximum number of points in the twilight zone
used for glyph hinting.
maxStorage
The maximum number of elements in the storage
area used for glyph hinting.
maxFunctionDefs
The maximum number of function definitions in the
TrueType bytecode for this font.
maxInstructionDefs
The maximum number of instruction definitions in
the TrueType bytecode for this font.
maxStackElements
The maximum number of stack elements used during
bytecode interpretation.
maxSizeOfInstructions
The maximum number of TrueType opcodes used for
glyph hinting.
maxComponentElements
An obscure value related to composite glyphs
definitions.
maxComponentDepth
An obscure value related to composite glyphs
definitions. Probably the maximum number of
simple glyphs in a composite.