Chapter 7 Rational B-spline (NURBS) Surfaces basis.c tbasis.c Calculates the B-spline basis functions. frbsurf.c tfrbsurf.c Calculates and test the fast B-spline surface algorithm. knot.c tknot.c Calculates an open knot vector. rbspsu

适用于AutoCAD的一个单行文字求和程序，用Lisp语音明码编写。-AutoCAD for a single word summation procedures, clearly prepared to use Lisp voice.

ohen-sutherland直线裁剪算法(The algorithm also called the encoding algorithm, the clipping window four edges where the line can put the plane into 9 regions, each region of the encoding including four is inside the 0 and 1 (for example, x coordinates less

在AutoCAD中画很多线段，可以用此小程序来统计这些线段的长度之和。(A lot of line segments are drawn in AutoCAD, and this small program can be used to count the sum of the length of these lines.)