关键词:面向对象;图形操作;I/O;
The Design and Realization of a Vector Graphics Tool
Abstract
The Vector Graphics system is one of the most important and difficult parts for GIS(Geographical Information System) development with VC++. The Vector Graphics system mainly includes implementing different drawing functions under the environment provided by VC + + 6.0, organizing and managing vector-based graphic data by means of object-based methods.
The idea of object-oriented is introduced in this paper, the geographic elements in the system are classified into line, arc(circle) ,curve and text. The basic classes’ framework is proposed by analyzing the basic structure of the vector graphics system. A basic vector graphics tool system is designed and realized from the kind of organization, the view’s realization, the mouse’s alternately draws up, the graphics operation, the graph selected, migration, deletion, and so on. Different drawing functions are implemented, including spot, line, circle, surface and note text. The system has the ability of processing chart of symbols (namely graph block). The realizations of relative consummation graphics operation function and facilitates graph I/O function is given, as well as graph migration, deletion function.
Key words : Object-oriented; Graph operation; I/O;