Path: chuka.playstation.co.uk!news From: Andrew Partington Newsgroups: scee.yaroze.freetalk.english Subject: Re: Radar Sweep Date: Fri, 31 Oct 2003 01:06:07 +0000 Organization: PlayStation Net Yaroze (SCEE) Lines: 38 Message-ID: References: NNTP-Posting-Host: public2-ward1-6-cust140.manc.broadband.ntl.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 X-Accept-Language: en-us, en In-Reply-To: Kenny Millar wrote: > In my new block busting game (!) I'd like to do a kind of radar-sweep > effect. > A line comig from the centre of the screen and sweeping round clockwise, I > can manage that part so far so good, but I'd like to get that sort of fading > trail that you see on radar screens. > > I've no idea how to go about that part of it, would any one care to shed > some, er, 'light' on it for me? > > -kenny > > Maybe a transparent gouraud-shaded quad or triangle, with the leading edge set to the brightest colour and the trailing edge set to black? Or how about a GsLINE array - whenever you move the line, the other segments in the line buffer trail n pixels behind the front line. Either way has its pitfalls though. The image quality for the line buffer idea probably wouldn't be too hot if you didn't move the endpoints of the lines in the buffer appropriately - you'd end up with holes in the shaded bit if the origin was to remain the same for each line. And if you went with the gouraud-shaded primitive, then that might look a bit dodgy if you were to make it too wide - depends on how much fade you want. Just some ideas of the top of my head, i've not had to do anything similar so far so i'm not really sure how they'd turn out. Hope this helps, Andy P