The maximum baseline extent is the vertical space occupied by characters in the font. If you are setting the font-use indicator FATTR_FONTUSE_OUTLINE, you should set the maximum baseline extent to 0. Outline fonts take an equivalent value from the character cell attribute that is current when text is written to an output device.

The maximum baseline extent value is required to select an image font and must be specified in world coordinates. For image fonts, this is the vertical height in world coordinates of character images in the font. This field must be specified when requesting an image font with GpiCreateLogFont.

The maximum baseline extent measurement is shown in a previous figure. The maximum baseline extent in the FATTRS data structure is used for programming, unlike the maximum baseline extent in the FONTMETRICS data structure, which is only measurement as recommended by the font's designer.