laser-lovers@uw-beaver (02/06/85)
From: Gloger.es@XEROX.ARPA You ask for an explanation of "Bezier cubics." A Bezier curve is a particular kind of mathematical spline curve. A Bezier curve of order n is defined as a particular parametric function of a sequence of n+1 control points, the function involving power terms up to n. The curve so defined passes through the two endpoints and "tends toward" the in-between points. A cubic Bezier curve is one of order 3, defined by 4 control points, and using terms up to cubes in its defining function. Beziers have a relatively large number of the properties which it is useful for mathematical spline curves to have, for purposes both of interactive definition and efficient drawing out. Cubic Beziers seem to be particularly good in this regard. For an excellent technical presentation of the subject, see "Principles of Interactive Computer Graphics," by William Newman and Robert Sproull. (Newman and Sproull both worked at Xerox PARC during the writing of this book. Sproull is also the principal author of Xerox's Interpress printing language.)
laser-lovers@uw-beaver (02/10/85)
From: RSanders@DENVER.ARPA The most recent BYTE magazine (2/85) has an article titled "The Macintosh Office" which describes the LaserWriter. Most of the info has already been seen on Laser-Lovers, except for an interesting tidbit in a side box title "Adobe Systems and the PostScript Language": "... the fonts are sent as mathematical outlines (based on Bezier cubics) that can be stroked, filled, scaled, oriented or used as clipping boundaries." Since I am almost ignorant in this area, can someone explain "Bezier cubics"? I've never heard the term before. -- Rex