freetypy.TT_OS2.x_height

TT_OS2.x_height

This metric specifies the distance between the baseline and the approximate height of non-ascending lowercase letters measured in font units. This value would normally be specified by a type designer but in situations where that is not possible, for example when a legacy font is being converted, the value may be set equal to the top of the unscaled and unhinted glyph bounding box of the glyph encoded at U+0078 (LATIN SMALL LETTER X). If no glyph is encoded in this position the field should be set to 0.

This metric, if specified, can be used in font substitution: the x_height value of one font can be scaled to approximate the apparent size of another.