bolson@blake.acs.washington.edu (Ed Bolson) (02/07/90)
I have an application that uses a graphics tablet or mouse to enter points on a boundary of a displayed image. Normally I expect continuous input of points, and allow for backing up. However, editing is quite clumsy. In addition, several users would like to enter single points to define rough curves and then modify the curves. I have seen several programs where the user can "grab" part of the curve and move a point around, with the curve being redisplayed in real time. It seems probable that piecewise bezier curves or B-splines are being used, because the curve shape changes only locally. I have looked at some standard references and have to admit I do not understand enough of the math or its application to see how to rapidly refigure and replot these curves. Can anyone point me to some code (any language - I'm revoltingly multi-lingual) preferably, or a reference on actual implementations for rapidly rendering a curve smoothly fitting a set of points, and allowing for editing of this curve by moving or adding points? Thanks in advance. Ed Bolson Bolson@edstoy.hs.washington.edu (in case my signature file screws up again!)