DWRITE_FONT_METRICS structure (dwrite.h)

The DWRITE_FONT_METRICS structure specifies the metrics that are applicable to all glyphs within the font face.

Syntax

struct DWRITE_FONT_METRICS {
  UINT16 designUnitsPerEm;
  UINT16 ascent;
  UINT16 descent;
  INT16  lineGap;
  UINT16 capHeight;
  UINT16 xHeight;
  INT16  underlinePosition;
  UINT16 underlineThickness;
  INT16  strikethroughPosition;
  UINT16 strikethroughThickness;
};

Members

designUnitsPerEm

Type: UINT16

The number of font design units per em unit. Font files use their own coordinate system of font design units. A font design unit is the smallest measurable unit in the em square, an imaginary square that is used to size and align glyphs. The concept of em square is used as a reference scale factor when defining font size and device transformation semantics. The size of one em square is also commonly used to compute the paragraph indentation value.

ascent

Type: UINT16

The ascent value of the font face in font design units. Ascent is the distance from the top of font character alignment box to the English baseline.

descent

Type: UINT16

The descent value of the font face in font design units. Descent is the distance from the bottom of font character alignment box to the English baseline.

lineGap

Type: INT16

The line gap in font design units. Recommended additional white space to add between lines to improve legibility. The recommended line spacing (baseline-to-baseline distance) is the sum of ascent, descent, and lineGap. The line gap is usually positive or zero but can be negative, in which case the recommended line spacing is less than the height of the character alignment box.

capHeight

Type: UINT16

The cap height value of the font face in font design units. Cap height is the distance from the English baseline to the top of a typical English capital. Capital "H" is often used as a reference character for the purpose of calculating the cap height value.

xHeight

Type: UINT16

The x-height value of the font face in font design units. x-height is the distance from the English baseline to the top of lowercase letter "x", or a similar lowercase character.

underlinePosition

Type: INT16

The underline position value of the font face in font design units. Underline position is the position of underline relative to the English baseline. The value is usually made negative in order to place the underline below the baseline.

underlineThickness

Type: UINT16

The suggested underline thickness value of the font face in font design units.

strikethroughPosition

Type: INT16

The strikethrough position value of the font face in font design units. Strikethrough position is the position of strikethrough relative to the English baseline. The value is usually made positive in order to place the strikethrough above the baseline.

strikethroughThickness

Type: UINT16

The suggested strikethrough thickness value of the font face in font design units.

Requirements