7.1 Specifying Printer Font Metrics

Printers render text using one of two types of fonts: device fonts or fonts
provided by Windows. The two fonts differ with respect to the location of
the font's character data. The character data for device fonts is stored in
the printer or in a detachable font cartridge. The character data for a
Windows font is stored on disk. This means that printers render text faster
with device fonts because the bitmap or vector data is resident on the
device, and does not require downloading from disk to the printer.

In order to render text with device fonts and in order to retrieve font
data for application queries, the Microsoft Windows Universal Printer
Driver requires special font data or printer font metrics. This data is
stored in a PFM file. The data includes:

o   A bit flag specifying whether the font is a bitmap or a vector font.

o   The point size.

o   The resolutions at which the font was digitized.

o   The leading values.

o   The font name.

o   The printer command which selects the font.

o   The printer command which cancels the selection of the font.

The PFM dialog box contains controls in which you specify a printer's
font-metrics and font-selection commands. The following illustration shows
a PFM dialog box:

bitmap:  pfmdlg

The examples in the following sections are based on a 12-pitch device font
for the Diconix 150 Plus printer.

The Microsoft Windows Device Driver Adaptation Kit also contains a Printer
Font Metrics (PFM) Editor for editing fonts. For more information about the
editor, see the Microsoft Windows Printers and Fonts Kit.