From: Shawn Hargreaves Newsgroups: comp.os.msdos.djgpp Subject: Re: Allegro's xor_mode Date: Sun, 28 Sep 1997 13:31:15 +0100 Organization: None Distribution: world Message-ID: References: <342C3CA0 DOT 52BE AT club-internet DOT fr> NNTP-Posting-Host: talula.demon.co.uk MIME-Version: 1.0 Lines: 19 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk Charles Mennerat writes: >When I try to draw with a specific color(drawing a sizable frame for a >mouse pointer), nothing happens.(When i put the white color using >xor_mode it's an ugly color that appears).If i turn off xor_mode the >right color appears.Can someone tell me what did i forget to do? What colors are you trying to draw? This behaviour is probably correct: the result of an XOR drawing operation is totally dependent on what the colors are and how your palette is set up. For example, (x ^ 0) == x, so drawing color zero in an XOR mode will have no effect at all! If your white color is #255, doing an XOR with it will toggle all the bits between zero and one, so the resulting color will be a binary opposite of the original. Whether this looks good or not will depend on what these colors actually are... -- Shawn Hargreaves - shawn AT talula DOT demon DOT co DOT uk - http://www.talula.demon.co.uk/ Beauty is a French phonetic corruption of a short cloth neck ornament.