From: Jonathan Foster Newsgroups: comp.os.msdos.djgpp Subject: Re: Newbie seeks help with rotating triangle program Date: Wed, 15 Oct 1997 16:38:12 +0100 Organization: University of Kent at Canterbury, England Lines: 18 Message-ID: <3444E364.6CDF@ukc.ac.uk> References: <19971015041101 DOT AAA17302 AT ladder01 DOT news DOT aol DOT com> NNTP-Posting-Host: dhcp2dc9.ukc.ac.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk Joshua Hab wrote: > x=(RADIUS_LENGTH*(cos(theta/360*6.28)))+CENTER_X ^^^^^^^^^ This is a problem with number types. The fragment "theta/360" is taking an "int theta" and dividing it by the integer 360. The result will be rounded to an _integer_ according to the ANSI C spec, and because the answer is less than 1 this means the angle will always be rounded to zero. Try this: "theta/360.0*6.28" The "360.0" is now a _float_, so the value of "theta" is made into a float. This allows the division to give a fractional answer, and it should work. -- Jon Foster. (1st Year Maths/Computer Science Student)