Gets the distance from the top end of the vertical advance vector to the top edge of the black box for the glyphs represented by the GlyphTypeface object.
Assembly: PresentationCore (in PresentationCore.dll)
The value is positive when the top edge of the black box is within the alignment rectangle defined by the advance height and font cell height. The font cell height is a horizontal dimension in vertical layout.
The value is negative when the top edge of the black box overhangs the alignment rectangle.