Path: chuka.playstation.co.uk!news From: "Rikki Prince" Newsgroups: scee.yaroze.beginners Subject: Re: Collision Detection!.....(Joy) Date: Sun, 20 Jun 1999 12:46:16 +0100 Organization: PlayStation Net Yaroze (SCEE) Lines: 49 Message-ID: <7kikb8$33u8@chuka.playstation.co.uk> References: <7kdntq$4fj13@chuka.playstation.co.uk> <7kdqqp$4fj15@chuka.playstation.co.uk> <7ker42$4fj17@chuka.playstation.co.uk> NNTP-Posting-Host: th-gt141-022.pool.dircon.co.uk X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.00.2014.211 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211 Scott Ward wrote in message news:7ker42$4fj17@chuka.playstation.co.uk... > Rikki, > As always Rikki, you are only too pleased to help and you should > be commended for it. It is much appreciated. > > So far, your comments are definately food for thought, however, there are > still a couple of points that you, or anyone else for that matter, might be > able to clear up. > The more I think about it the more I'm starting to get my head around the > concept of testing for collision in main memory BUT why is the image stored > as 2-bit? If for example the mask is stored so that a 1 represents the image > and a 0 represents the transparent bits wouldn't that only require one bit > per pixel? > This is probably where you laugh at me but wouldn't that make it a 1-bit > image? Why two bits per pixel (or is that not what 2-bit means?). > You've got me there, your argument seems perfectly logical, and I too do not understand the need for 2bit, rather than 1bit image mask. Maybe James mistyped 2 instead of 1, which is easy, it would have been harder to mistype 8bit instead of 24bit for example! The only other possible alternative could be that it needs to be 2bit for easy conversion from any of the possible sprite resolutions (4, 8 and 16 + 24 bits), but this doesn't quite work, as once you've got it to 2bit, it'll be just as easy to get it into 1bit. As I say I'm just throwing ideas around, in the hope that the answer hits someone on the head, and we realise! > Also, I could probably work out a mask for my image but in the game I use > the GsSPRITE .rotate argument to rotate the main sprite so I would really > need to be able to draw the mask in game depending on the position of the > sprite. Any ideas? > Maybe this is where the bit shifting comes in, but really we'd need an expert, such as Mr. Russell, to explain what bit shifting you'd need to do to simulate the current position and rotation, but it seems they've all gone on holiday, or something equally lazy! j/k. > Cheers, > > Scott > Rikki