Windows printing

General Information

Unit of measure = twips:
Regardless of the nature of the printer being addressed, the pixel resolution used by the windows printer driver is in units referred to as twips. One twip is equal to 1/20th of a printer's point. One point is equal to 1/72nd of an inch. Therefore there are 1440 twips per inch or 567 twips per centimeter. Unless otherwise stated, all Windows print functions use twips as the unit of measure.

Page sizes::
When calculating the dimensions of a printer page, keep in mind that in many cases the entire page is not always printable (e.g., Hewlett Packard laser printers have a 1/4" unprintable area on all four sides). Therefore, it may be necessary to inquire as to not just the page size, but also the offset from the physical page boundary to the printable page boundary. See (GetPageInfo) for additional information.

Fonts:
Font sizes are requested in tenth's of a point. This does not guarantee that the font created is exactly the requested size. It is important to inquire after selecting a font as to the actual size the font mapper created. Also, when printing text there is usually some additional space (external leading) added between lines. This space is specified by the font designer and should be combined with the font height to determine the height of a line. See (GetFontInfo) for additional information.

Related usefiles:

#COSUTLD	Constants and variables commonly used by other USE files and applications for parameter passing (TRUE, FALSE, NULL, etc).
#PTRCTLD	Printer driver function constants (paper sizes, bins, etc.)
#LOGFNT	Functions used to manipulate fonts
#LOGFNTD	Constants and variables used by #LOGFNT
#FILFND	Contains routine for finding DOS files living in Comet directories
#FILFNDD	Constants and variables used by #FILFND
#DESERVE	Declaratives for Driver Event Server programs
#COSPTR	Contains subroutines to perform all of the printer driver functions. This file has been made obsolete with the release of mnemonic printing.
#COSPTRD	Constants and variables used by #COSPTR

For more information, see Windows printer mnemonics.