Inside Macintosh: QuickDraw GX Objects /

Chapter 6 - Transform Objects / Transform Objects Reference

Functions / Transforming Shapes by Modifying Transform Mappings

GXMapTransform

You can use the GXMapTransform function to apply a separate mapping matrix to the mapping of a transform object, so that its associated shape is additionally transformed according to the specifications of the matrix.

void GXMapTransform(gxTransform target, const gxMapping *map);

target

A reference to the transform object whose mapping property you want to alter.

map

A pointer to a mapping structure containing the information you want to incorporate into the target transform's mapping.

DESCRIPTION

The GXMapTransform function calculates a new mapping matrix for the transform object referenced by the target parameter. It does so by concatenating the mappings (performing matrix multiplication). When applied to a shape, the transform's new mapping matrix performs the same transformations as the transform's original matrix as well as the transformations indicated by the matrix pointed to by the map parameter.

ERRORS, WARNINGS, AND NOTICES

Errors
out_of_memory
transform_is_nil
Warnings
map_transform_out_of_range
Notices (debugging version)
mapping_unaffected

SEE ALSO

For information about mapping matrices in general, see the mathematics chapter of Inside Macintosh: QuickDraw GX Environment and Utilities.

To use a mapping matrix to alter a shape's geometry, use the GXMapShape function, described on page 6-72.