一、引言图形系统或图形显示系统是在六十年代初期发展起来的;图形显示在开始时硬件比较简单,大部分图形功能都是由软件完成的,因此,一般都由大型计算机来组成图形系统。在以后的几年中,图形显示设备中发展了多种多样的专用硬设备,如矢量产生器,字符产生器,元产生器以及作图形转换用的专用矩阵乘法器和剪切除法器,这样就使图 I. INTRODUCTION Graphic system or graphic display system was developed in the early 1960s; Graphic display hardware at the outset is relatively simple, most of the graphics functions are completed by the software, therefore, are generally composed of a large computer graphics system . In the next few years, a wide variety of specialized hardware devices such as vector generators, character generators, meta generators, and dedicated matrix multipliers and cut dividers for graphics conversion have been developed in graphics display devices Just make the picture