From: Brinkerhoff Newsgroups: comp.os.msdos.djgpp Subject: More wonderful Allegro Clipping Date: Sun, 08 Mar 1998 00:23:03 -0800 Organization: Dave's Machine Service Lines: 26 Message-ID: <35025567.1E08@ainop.com> References: <3500E3E8 DOT 54BA AT ainop DOT com> <350140ba DOT 142174296 AT isflak DOT arcticnet DOT no> NNTP-Posting-Host: mast44.ainop.com 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 Here's what I don't get about the u and v coords for texture mapping. You say I should interpolate them the same way as the x,y coords. Well suppose you have a quad poly. It is a rectangle (4 90 degree angles) and two of the sides are perpendicular to the y-axis (this is basically what I'll be dealing with, anyway). Take a look at these wonderful ascii diagrams (viewed as though looking down) | / (a) ------------ (b) ------------ | / (Let's just assume that the diagrams are basically the same, save for the fact that b's poly is rotated slightly, meaning that the distance from the end of a poly, to the intersection with the viewplane is the same in both diagrams) Now, buy calculating the u and v coords the way i did the x,y coords, it seems as though i would get two different vales for u,v coords, when in fact, they should be the same. Can you explain more on how to interpolate the u,v texture mapping coords?