Specifications

CHAPTER 3
Application Program Interface
30
GeometryEngine Component
GeometryEngine Component 3
This section describes those GeometryEngine component functions that can be used by
the developer. It is assumed that you are already familiar with the Component Manager
and, more specifically, with the AV Architecture to which the GeometryEngine
component belongs.
Overview 3
The GeometryEngine component, at present, provides developers with access to the
overscan feature of the AppleVision displays. Using this feature, your application can
programmatically control the overscan setting.
If you implement the overscan feature on your display, the edges of the image area go as
far as they can to the edge of the screen without distorting the image. If you turn on
overscan, you cannot make any changes to other Geometry selections, such as height/
width adjustment. Normally, you would not use the overscan feature. However, you
might want to turn the feature on to view full-screen digital video, or total immersion
games. You can also use the feature any time you want to shield the user from details of
the computer operation.
Like other engines belonging to the AV Architecture, the GeometryEngine component is
based on Component Manager components. The GeometryEngine component has the
following component description:
componentType = ‘avec’
Indicates that the component is a video panel.
componentSubType = ‘geoe’
Identifies the specific engine.
componentManufacturer = ‘appl’
Identifies Apple Computer, Inc. as the manufacturer.