🚀 go-pugleaf

In article <28315.27aabebc@kuhub.cc.ukans.edu>, heping@kuhub.cc.ukans.edu writes:
> I need algorithms for drawing arcs and ellipses, could someone help me?
> Thanks
> 
> Phil

When you interview for a programming job at Microsoft, they spring a pop
quiz on you.  One of the questions they asked me (years ago) was "design
an algorithm to draw an arc efficiently."  The answer they're looking 
for is something like Bresenham's algorithm which plots a point on the
arc { x = 0, y = r } and incrementally draws the arc by determining the
adjacent pixel with the least error.  My guess was scan-line by scan-line,
but this results in holes--a flood fill would "escape."

Bresenham's algorithm is described in "Fundamentals of Interactive
Computer Graphics," by Foley and Van Dam.  I see there's a new edition
out, but it's $60 or so--the good news is that the older edition should
now be even cheaper used.

Hope it helps.

/alastair/