Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /

Chapter 4 - Printing Messages / Printing Messages Reference

Constants and Data Types for the PostScript Imaging System

PostScript Imaging System Structure

The PostScript imaging system structure, of data type gxPostScriptImageDataRec, is allocated and set up by QuickDraw GX during the implementation of the GXPostScriptGetDocumentProcSetList and GXPostScriptDownloadProcSetList messages, whose descriptions begin on page 4-112. This structure contains information describing the contents of a document that is to be imaged and quantifies the limitations of the device to which the document
is to be imaged. QuickDraw GX fills in all the fields in the structure with default values, but your printing extension or printer driver can change any of these fields or use them to derive information about the imaging of the document. For more information about how the fields in this structure are used for color printing, see the section "Color Printing" beginning on page 3-50 in the chapter "Printer Drivers."

struct gxPostScriptImageDataRec {
   short                      languageLevel;
   gxColorSpace               devCSpace;
   gxColorProfile             devCProfile;
   gxPostScriptRenderOptions  renderOptions;
   long                       pathLimit;
   short                      gsaveLimit;
   short                      opStackLimit;
   scalerStreamTypeFlag       fontType;
   long                       printerVM;
   long                       reserved0;
}; 
typedef struct gxPostScriptImageDataRec 
gxPostScriptImageDataRec, *gxPostScriptImageDataPtr, 
**gxPostScriptImageDataHandle;;

Field Description

languageLevel

The language level for the PostScript printer to which your driver is imaging the document.

devCSpace

The color space used for this device. The color-space value constants are shown in the chapter "Colors and Color-Related Objects" in Inside Macintosh: QuickDraw GX Objects. The values that are valid for this field are gxGraySpace, gxCMYKSpace, and gxRGBSpace.

devCProfile

The color profile for this device. Color profiles are explained in the chapter "Colors and Color-Related Objects" in Inside Macintosh: QuickDraw GX Objects.

renderOptions

Rendering options for the PostScript printer. This value is the combined value of the constants that you include from the PostScript render options enumeration, which is described in the next section.

pathLimit

The largest number of points that can be active in the device during the imaging process without generating a PostScript limitcheck error, which is described in PostScript Language Reference Manual, 2nd Edition.

gsaveLimit

The greatest number of gsaves that can be performed on the device without generating a PostScript limitcheck error.

opStackLimit

The maximum number of objects that can be placed in the stack at any one time without generating a PostScript limitcheck error.

fontType

The stream type that the imaging system needs to use when downloading a font. The possible values are described in Inside Macintosh: Typography.

printerVM

The amount of memory available in the printer.

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