Hsu, Y. H.Kuo, Y. S.2014-10-212014-10-2119921467-8659https://doi.org/10.1111/1467-8659.1130071HAGI is an object-oriented graphics system developed on top of the X window system. In addition to providing facilities that structured graphics systems such as GKS usually have, HAGI supports a high- level graphics paradigm with the following features: * + In addition to graphical objects, the system provides a class of application objects with a higher level of abstraction than graphical objects. * + Graphics manipulation operations can be issued simplyfrom application objects without explicitly referring to specific graphical objects. Thus graphics manipulation appears to be transparent to application programmers. * + Graphical objects are designed to encompass more semantics, thus are at a level close to the application. For example, they useflexible visual objects to determine their visual appearance.HAGI provides such a high-level application/graphics interface by maintaining a dependency relationship between graphical objects and application objects.10.1111/1467-8659.113007171-80