The ATSUTextMeasurement type represents the glyph bounds (exact outline metrics) of onscreen glyphs. You pass the ATSUTextMeasurement type to functions that draw, measure, hit-test, and obtain the glyph bounds for text. The ATSUTextMeasurement type can be also used to set and get imposed glyph width, line width, line ascent, and line descent; see Style Run Attribute Tag Constants and Text Layout Attribute Tag Constants, respectively.
typedef Fixed ATSUTextMeasurement;
