Setting Up QuickDraw GX Memory
Your application enters the QuickDraw GX environment by creating a graphics client.
A graphics client is an object that represents a memory environment set up for your application by QuickDraw GX. It consists of a QuickDraw GX heap and the global variables needed by QuickDraw GX. It represents your application's individual QuickDraw GX world.Normally, each application creates and uses a single graphics client, although it is possible to create and use more than one at a time. In most cases, you don't even explicitly set up a graphics client at all; one is created for you as you begin making QuickDraw GX calls to create and use objects. For more information, see the memory management chapter of Inside Macintosh: QuickDraw GX Environment and Utilities.