This bug: http://bugzilla.gnome.org/show_bug.cgi?id=132145 Was present in the Bugzilla for a long time now. It was reported because the Frosty Logo script did not render correctly. Kevin Cozens discovered it was due to the Sparkle Plug-in. Eventually, I decided to resolve it. I did that by comparing the code (portion by portion and line by line) to the code in GIMP 1.2. As a result of this process, I found four regression bugs[1] that were fixed in this patch: http://bugzilla.gnome.org/attachment.cgi?id=35345&action=view However, there were still problems apparent. I temporarily hacked the code to settle both plug-ins on the same identical pseudo-random number generator, with the same seed, and compared the results. They were very different. So I decided to add traces in the code to see where they were different. As I went to add some traces, I discovered another regression bug, very similar to another one I discovered previously, which I fixed. This seems to have corrected the problem altogether, but the results were still not identical. I added more traces, enough to cause both dumps to become a 1.5 GB (no typo here) file, and then I discovered that a parameter passed to a function was different in the plug-ins. I found out that it was a bug, because the 4th byte (possibly alpha) of a color was not initialized. This bug was still present in gimp 1.2.x. I fixed this bug too, and afterwards the results were identical. The patch with both of the newer fixes is this: http://bugzilla.gnome.org/attachment.cgi?id=35501&action=view In any case, I still noticed a problem. In the upper part of the image, the shadows had completely horizontal edges. I noticed that this problem still existed in GIMP 1.0.x (!), but it was still disturbing. After a lot of investigation, and trying to reduce the script to a minimum that still exhibits this problem, I found out the problem was because: <<< I discovered that the problem with the shadow was due to the fact that the shadow was generated within the image boundaries and then the shadow layer was moved (= translated) by an offset which caused it to have horizontal edges at the top of the resultant image. >>> I prepared a patch to fix it. Sven told me to commit it to the CVS, which I did. I forgot to commit it to the GIMP 2.2 branch, which Sven was gracious enough to do late last night. So now the sparkle plug-in is hopefully fully bug-free, and the Frosty logo is back in action. Happy sparkling! Regards, Shlomi Fish [1] - Well, one of them was just a swapped order for fetching two consecutive random numbers from the random number generator, but that was revised too. --------------------------------------------------------------------- Shlomi Fish shlomif@xxxxxxxxxxx Homepage: http://www.shlomifish.org/ Knuth is not God! It took him two days to build the Roman Empire.
