(v13) Adding extra dot shapes

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP.

As well using as the spot shapes built into the RIP, it is possible to add and use new screens. The built-in shapes are available in the Dot Shape menu in the Screening dialog accessed from the Page Setup dialog box in the GUI version and by using the OverrideSpotFunctionName system parameter, described in (v13) Deciding which screen properties to use.

Also, built-in dot shapes already on the menu can be suppressed, and built-in dot shapes not already on the menu can be added. (This happens automatically when HDS, for example, is turned on).

The RIP requires two or three pieces of information about each new screen, depending on whether or not it is to appear on the Dot Shape menu:

• The definition of the dot shape
• An internal name by which the screen is to be known in the interpreter
• An external name which is to appear to the user in the Dot Shape menu

The new internal names can be used in the same way as the built-in ones, as values of OverrideSpotFunctionName for example. Internal names can identify either spot functions or complete halftone dictionaries (including type 5 halftone dictionaries), and aspects of halftone dictionaries can be used to supply defaults which can be overridden or always used according to requirements.

The list of names and corresponding spot functions and halftone dictionaries matched by OverrideSpotFunctionName is stored in the dictionary switchscreens in $printerdict. This dictionary should not be modified directly (though it could be examined from PostScript language if required, for example to enumerate the internal names). There are two ways to add to this: (1) Editing sf.ps and (2) using the HqnHtm procset.