little@odin.ucsd.edu (Glenn Little) (08/31/88)
We have a fairly new version of the "gremlin" picture editor for suns, and an apparently slightly older version of the "grn" filter that converts gremlin output to troff input. The problem is this: The new gremlin's curve facility is now has the option of doing an explicit B-spline, Bezier, or Interpolated curve. In the output file, gremlin puts lines that look like CURVE BSPLINE 144.00 392.00 256.00 320.00 52.00 272.00 * for a three point spline curve. The Bezier curve replaces BSPLINE with BEZIER, and the Interpolated curve leaves out the modifier altogether. The problem is, our grn program doesn't want to see the word BSPLINE (or BEZIER, or anything for that matter) there. In fact, with that word there, a couple of extra points are added to the curve, leading to some pretty ridiculous figures. If I take the word BSPLINE out, the file works more or less the way I'd expect. I did notice though that the curve itself looked different (but not radically so) from the way it looked in the gremlin editor, to the way it looked when I used dsun.tool to preview it on the sun, to the way it looked when I actually printed it (the last two after I took out the BSPLINE.) My questions are 1) is there a newer version of grn out that will not choke on the BSPLINE? Or should we just tell our users to use the Interpolated curve only? 2) are the differences between all three methods of looking at my picture reasonable (they are quite noticeable... a half inch to an inch depending on the layout of points, but at least the curve resembles what was originally drawn), or is there a problem with our installation? Thanks for any information. Glenn Little little%cs@ucsd.edu