Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /

Chapter 4 - Printing Messages / Printing Messages Reference

Printing Messages / PostScript Imaging Messages

GXPostScriptGetPrinterGlyphsInformation

QuickDraw GX sends the GXPostScriptGetPrinterGlyphsInformation message to allow a printing extension or printer driver to communicate with the imaging system about the fonts and glyphs that are resident in the output device. You can override the GXPostScriptGetPrinterGlyphsInformation message if you are doing your own font management. Your override of the GXPostScriptGetPrinterGlyphsInformation message must match the following formal declaration:

OSErr MyPostScriptGetPrinterGlyphsInformation (
                                 gxPrinterGlyphsRec *glyphPtr);

glyphPtr

A pointer to a PostScript glyphs structure.

function result

An error code. The value noErr indicates that the operation was successful.

DESCRIPTION

The PostScript imaging system sends the GXPostScriptGetPrinterGlyphsInformation message before it starts to image a document. It uses the information gathered by this message to determine which fonts or which glyphs in a font need to be downloaded to the printer for the document to be printed.

On entry to this message, the theFont field of the PostScript glyphs structure, of data type gxPrinterGlyphsRec, must be filled in with a valid font reference to the font
for which information is desired. You can fill in the platform, script, and language fields of the PostScript glyphs structure to tell the imaging system which glyphs from a font are present in the printer.

If the platform field of the structure has the value -1, then the script and language field values are ignored, and the glyphBits array is filled in with the glyphs that are actually present for the font.

If the platform field of the structure has any value other than -1, then the platform, script, and language fields together define how the imaging system maps glyphs into the printer's encoding scheme.

The default implementation of the GXPostScriptGetPrinterGlyphsInformation message uses the information that was gathered by the GXPostScriptQueryPrinter message to fill out the PostScript glyphs structure. It also looks for a 'pfnt' resource that has the same font name as that in the theFont field of the structure and gathers information from that resource.

SPECIAL CONSIDERATIONS

You must forward the GXPostScriptGetPrinterGlyphsInformation message.

RESULT CODES

gxSegmentLoadFailedErr	A required code segment could not be found, or there was not enough memory to load it.
gxPrUserAbortErr	The user has canceled printing.

The default implementation of the GXPostScriptGetPrinterGlyphsInformation message can also return the communications errors that are listed in Table 4-2 on page 4-42.

SEE ALSO

The PostScript glyphs structure is described on page 4-28.

The GXPostScriptQueryPrinter messages is described on page 4-101.

The PostScript printer font ('pfnt') resource is described on page 6-84 in the chapter "Printing Resources."

For more information about how the imaging system maps glyphs, read about the 'cmap' table in the book Inside Macintosh: QuickDraw GX Typography.

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