Inside Macintosh: QuickDraw GX Objects /

Chapter 7 - View-Related Objects / View-Related Objects Reference

View Port Functions / Manipulating View Port Object Properties

GXSetViewPortHalftone

You can use the GXSetViewPortHalftone function to assign a halftone property to a view port object.

void GXSetViewPortHalftone(gxViewPort target,
                           const gxHalftone *data);

target

A reference to the view port whose halftone you wish to change.

data

A pointer to a halftone structure containing the data with which to set the view port's halftone property.

DESCRIPTION

The GXSetViewPortHalftone function sets the halftone for the target view port. If the data parameter is set to nil, halftones are not used when drawing to this view port.

ERRORS, WARNINGS, AND NOTICES

Errors
invalid_viewPort_reference
frequency_parameter_out_of_range	(debugging version)
tinting_parameter_out_of_range	(debugging version)
method_parameter_out_of_range	(debugging version)
space_may_not_be_indexed	(debugging version)
colorSpace_out_of_range	(debugging version)
Notices (debugging version)
halftone_already_set

SEE ALSO

For an example of the use of this function, see Listing 7-1 on page 7-42.

For information about the halftone property, see "Halftone" beginning on page 7-13.

To set the halftone of a view port, use the GXGetViewPortHalftone function, described in the previous section.