Thanks Philip. That indeed does seem to be the problem. Thanks for the suggested fix as well.
On Sunday, January 27, 2002, at 10:12 AM, Philip Chumbley wrote: > To illustrate the situation in one dimension, if a line is 99 > pixels wide, > its centerpoint is at 50 with 49 pixels before and 49 pixels after the > centerpoint. But if the line is 100 pixels wide, the > centerpoint is actually > at 50 1/2. Since you can't center the line on a half pixel, > the line would > be shifted slightly right or left from true center (depending > whether you > round up or truncate the number) so the image is now offset. > If you now make > the line 99 pixels wide again it will stay centered in the same > place but > switching it back to 100 pixels wide again will shift it once > again. If the > half-way points are rounded up (ie. 50 1/2 --> 51), the effect > would be that > a line would drift to the left or an image to the upper left. > To correct for > that, simply read the location of the first image into a > variable (oldLoc) > and include a line saying: > > set the loc of image myImage to oldLoc > > after setting the filename. Be aware that you may see the image "jump" > slightly. If that is unacceptable, make the image invisible, set the > fileName to the new name, set the loc to the oldLoc , and then make it > visible. In my application I use two images. While viewing > one, I set the > file name of the invisible one and reposition it and then hide > one and show > the other. > > Hope this helps. > > Philip Chumbley > -- John R. Vokey, Ph.D. |\ _,,,---,,_ Professor /,`.-'`' -. ;-;;,_ Department of Psychology and Neuroscience |,4- ) )-,_. ,\ ( `'-' University of Lethbridge '---''(_/--' `-'\_) _______________________________________________ metacard mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/metacard