Using Picture Shapes (IM: XG)

Inside Macintosh: QuickDraw GX Graphics /: Chapter 6 - Picture Shapes

Using Picture Shapes
This section shows you how to create, draw, edit, and hit-test picture shapes. In particular, this section shows you how to

create and draw pictures
add items to a picture
remove and replace items in a picture
provide overriding styles, inks, and transforms for the items in a picture
add multiple copies of a shape to a picture
copy objects when adding them to a picture
create hierarchies of pictures
hit-test pictures

Although the geometry of a picture shape does not contain geometric points, a picture shape can contain shapes whose geometries do contain geometric points. For this reason, some of the sample functions in this section need to specify geometric points, which are made up of two fixed-point numbers. To convert integers to fixed-point numbers when specifying geometric points, QuickDraw GX provides the GXIntToFixed macro:
#define GXIntToFixed(a) ((Fixed)(a) << 16)
QuickDraw GX also provides the ff macro as a convenient alias:
#define ff(a) GXIntToFixed(a)
The sample functions throughout this section use the ff macro when converting an integer constant to a fixed-point constant.

Subtopics

Creating and Drawing Picture Shapes

Getting and Setting Picture Geometries

Adding Items to a Picture

Removing and Replacing Items in a Picture

Using Overriding Styles, Inks, and Transforms

Adding Multiple References

Adding Items With the Unique Items Attribute Set

Creating Picture Hierarchies

Hit-Testing Pictures