Path: utzoo!utgpu!attcan!uunet!lll-winken!lll-tis!ames!mailrus!tut.cis.ohio-state.edu!ukma!rutgers!rochester!pt.cs.cmu.edu!andrew.cmu.edu!kw1r+ From: kw1r+@andrew.cmu.edu (Kevin Whitley) Newsgroups: comp.sys.mac.programmer Subject: Re: color "xor" Message-ID: Date: 15 Dec 88 22:22:26 GMT Organization: Carnegie Mellon Lines: 21 Larry Rosenstein (of Apple) suggested that I use the hilite mode to satisfy my request for xor in color. Although this doesn't do everything I wanted, it is better than the alternative (which is to just use the ridiculous default xor). But I should point out that there was an error in his note. >To reverse the operation, you have to set up the highlight and background >colors appropriately. (This is not like XOR where 2 successive calls undo >each other.) In fact mode hilite IS like Xor. Hilite swaps background & hilite color. Drawing (with the same hilite color and background color, mind you) over the same area swaps everything back. So things are even rosier than he suggested. I would like to add that although I was able to get this to work just fine by twiddling bit 7 of the global variable hiliteMode, I didn't seem to be able to get it to work by calling PenMode(HiliteMode). This is a small detail, perhaps I have overlooked something. Thank you kindly Larry, I appreciate the help. Kevin Whitley kw1r@andrew.cmu.edu