Class Hierarchy
AcRxObject AcGiDrawable AcDbObject AcDbBackground AcDbGradientBackground AcDbGroundPlaneBackground AcDbIBLBackground AcDbImageBackground AcDbSkyBackground AcDbSolidBackground
C++
class AcDbBackground : public AcDbObject;
File
dbBackground.h
Description
Base class of all background objects that describe a viewport background. There are three types of concrete background types: AcDbSolidBackground, AcDbGradientBackground and AcDbImageBackground. Each object should reside in the ACAD_BACKGROUND dictionary. If a tilemode viewport or a paperspace viewport has a background, it has to refer to one of these classes.
The application that sets a viewport background has the following responsibilities:
- Create a new background, give it a unique name, set appropriate properties and append it to the ACAD_BACKGROUND dictionary.
- Remove the previous background object from the dictionary (if it does not require it anymore).
Notes
A background object should not be shared among viewports. When a viewport is deleted, its associated background will be deleted too.