nuget
The Vertical Header Table contains information for vertical layout
VheaTable
01 Syntax
Microsoft.VisualBasic.Drawing.Fonts.TrueType.Tables.VheaTable
02 Methods
| Name | Overloads | Summary |
|---|---|---|
| FromReader | 1 |
03 Properties
| Name | Overloads | Summary |
|---|---|---|
| Version | 1 | Version number of the vertical header table |
| Ascender | 1 | The vertical typographic ascender for this font. |
| Descender | 1 | The vertical typographic descender for this font. |
| LineGap | 1 | The vertical typographic gap for this font. |
| AdvanceHeightMax | 1 | Maximum advance height measurement in FUnits. |
| MinTopSideBearing | 1 | Minimum top sidebearing value in FUnits. |
| MinBottomSideBearing | 1 | Minimum bottom sidebearing value in FUnits. |
| YMaxExtent | 1 | Defined as yMaxExtent = max(tsb + (yMax - yMin)). |
| CaretSlopeRise | 1 | The value of the caretSlopeRise field divided by the value of the caretSlopeRun Field determines the slope of the caret. |
| CaretSlopeRun | 1 | See the caretSlopeRise field. |
| CaretOffset | 1 | The amount by which the highlight on a slanted glyph needs to be shifted away from the glyph in order to produce the best appearance. |
| MetricDataFormat | 1 | 0 for current format. |
| NumberOfVMetrics | 1 | Number of advance heights in the 'vmtx' table |
| Empty | 1 |
04 Members
Version
Version number of the vertical header table
Ascender
The vertical typographic ascender for this font. It is the distance in FUnits from the vertical center baseline to the right edge of the design space for CJK / ideographic glyphs (or “ideographic em box”).
It is usually set to(head.unitsPerEm)/2. For example, a font with an em of 1000 FUnits will set this field to 500. See the Baseline tags section of the OpenType Layout Tag Registry for a description of the ideographic em-box.
Remarks
Named vertTypoAscender in table version 1.1
Descender
The vertical typographic descender for this font. It is the distance in FUnits from the vertical center baseline to the left edge of the design space for CJK / ideographic glyphs.
It is usually set to -(head.unitsPerEm/2). For example, a font with an em of 1000 FUnits will set this field to -500.
Remarks
Named vertTypoDescender in table version 1.1
LineGap
The vertical typographic gap for this font. An application can determine the recommended line spacing for single spaced vertical text for an OpenType font by the following expression: ideo embox width + vhea.vertTypoLineGap
Remarks
Named vertTypoLineGap in table version 1.1
AdvanceHeightMax
Maximum advance height measurement in FUnits.
MinTopSideBearing
Minimum top sidebearing value in FUnits.
MinBottomSideBearing
Minimum bottom sidebearing value in FUnits.
YMaxExtent
Defined as yMaxExtent = max(tsb + (yMax - yMin)).
CaretSlopeRise
The value of the caretSlopeRise field divided by the value of the caretSlopeRun Field determines the slope of the caret. A value of 0 for the rise and a value of 1 for the run specifies a horizontal caret. A value of 1 for the rise and a value of 0 for the run specifies a vertical caret. Intermediate values are desirable for fonts whose glyphs are oblique or italic. For a vertical font, a horizontal caret is best.
CaretSlopeRun
See the caretSlopeRise field. Value=1 for nonslanted vertical fonts.
CaretOffset
The amount by which the highlight on a slanted glyph needs to be shifted away from the glyph in order to produce the best appearance. Set value equal to 0 for nonslanted fonts.
MetricDataFormat
0 for current format.
NumberOfVMetrics
Number of advance heights in the 'vmtx' table
Empty
FromReader(FontReader,
TableRecordEntry)