Inside Macintosh: QuickDraw GX Objects /

Chapter 6 - Transform Objects / Transform Objects Reference

Functions / Getting and Setting the Mapping

GXGetShapeMapping

You can use the GXGetShapeMapping function to retrieve the mapping property of the transform object associated with a specified shape.

gxMapping *GXGetShapeMapping(gxShape source, gxMapping *map);

source

A reference to the shape whose transform object contains the mapping property you want to examine.

map

A pointer to the mapping structure. On return, the structure contains the mapping matrix of the source shape's transform.

function result

A pointer to the mapping property of the source shape's transform. (This value is the same as the value returned in the map parameter.)

DESCRIPTION

The GXGetShapeMapping function copies the mapping matrix information from the mapping property of the source shape's transform object into the mapping structure pointed to by the map parameter. The function also returns as its function result a pointer to this mapping structure.

Note that the returned mapping is a copy; you can alter it without affecting the mapping property of the source shape's transform. If you call this function and alter the mapping that it returns, you can then assign that changed mapping back to the shape's transform object by calling the GXSetShapeMapping function.

ERRORS, WARNINGS, AND NOTICES

Errors
out_of_memory
shape_is_nil
parameter_is_nil	(debugging version)

SEE ALSO

For information about the mapping property of the transform object, see the section "Mapping" beginning on page 6-10. For information about mapping matrices in general, see the mathematics chapter of Inside Macintosh: QuickDraw GX Environment and Utilities.