text_extents/[7,8]

     text_extents(+Fontable, +String, -Lbearing, -RBearing,
                  -Width, -Ascent, -Descent)
     text_extents(+Fontable, +String, -Lbearing, -RBearing,
                  -Width, -Ascent, -Descent, -Attribute_bits)
     

How much space would be occupied if String were drawn in in Fontable? Lbearing is the number of pixels to the left of the origin point; RBearing is the number of pixels to the right of the origin point; Ascent is the number of pixels above the origin point; and Descent is one greater than the number of pixels below the origin point. The reason Descent is one greater than what you would expect is that it allows you to add Ascent and Descent to determine the height of String.

String may be either an atom or list of character codes.