CairoFontExtents (gb.cairo)

This class stores metric information for a font. Values are given in the current user-space coordinate system.

Because font metrics are in user-space coordinates, they are mostly, but not entirely, independent of the current transformation matrix. If you call Cairo.Scale(2.0, 2.0), text will be drawn twice as big, but the reported text extents will not be doubled. They will change slightly due to hinting (so you can't assume that metrics are independent of the transformation matrix), but otherwise will remain unchanged.

Vlastnosti

Ascent	Return the distance that the font extends above the baseline.
Descent	Returns the distance that the font extends below the baseline.
Height	Return the recommended vertical distance between baselines when setting consecutive lines of text with the font.
MaxXAdvance	Return the maximum distance in the X direction that the the origin is advanced for any glyph in the font.
MaxYAdvance	Return the maximum distance in the Y direction that the the origin is advanced for any glyph in the font.