The AcGi implementation calls the setAttributes() function on a drawable to obtain the general rendering attributes to be used for the object's geometry, such as color, layer, and linetype. This call is made prior to calling the object's worldDraw() function, and AcGi uses the return value to determine how to handle most efficiently the object later on.
Normally you will not need to override the subSetAttributes() function, but if you do so, you must call the base class implementation first and return the same flags in the return value. The only alteration that can be made is to add additional flags to the return value. For more information on the return flags, see setAttributes() function in the ObjectARX Reference Guide.
The default implementation of AcDbEntity::subSetAttributes() sets up the color, layer, linetype, lineweight and plot style using the entity's current properties, and the return value includes the kDrawableIsEntity flag.