Hi, Thomas RIBO <tharibo@xxxxxxx> writes: > Sorry to interrupt your (more important) conversation, but I still have > problems with plugins. > I really can't figure out why my plugin runs on and on and.... finally > stopping some minutes later with a segmentation fault. > I don't have infinite loop (I trust, but maybe there are hidden one, > who knows =) but I think I'm doing something not the proper manner. > Could someone just have a lookup on my code to see if he (her) finds > anything with my use of libgimp? > > The code is here : http://tharibo.free.fr/GIMP/Textures.tar.gz > There are a C file, a header file and their Makefile. there are several flaws in your plug-in (see below) but the main problem is that you are trying to access data outside the drawable. The offending code is the calculation of the pixel_region in variencyMethod(): unsigned startRow = (unsigned) WINDOW_SIZE /2; unsigned endRow = inputDrawable->height - (unsigned) WINDOW_SIZE /2; unsigned startCol = (unsigned) WINDOW_SIZE /2; unsigned endCol = inputDrawable->width - (unsigned) WINDOW_SIZE /2; for(col = startCol; col <= endCol; col++) { unsigned startColWindow = col - (unsigned) WINDOW_SIZE /2; unsigned startRowWindow = row - (unsigned) WINDOW_SIZE /2; gimp_pixel_rgn_init(&window, inputDrawable, startColWindow, startRowWindow, WINDOW_SIZE, WINDOW_SIZE, FALSE, FALSE); ... } you assume that WINDOW_SIZE/2 + WINDOW_SIZE/2 == WINDOW_SIZE but since WINDOW_SIZE is odd (5) this is not true and you end up going one pixel too far, thus trying to access a tile outside the drawable. I was surprised that our error checking in libgimp is that bad, but there's not much we can do about that now. Some other flaws I've noticed are: - average() and variency both use a wrong index into the data array thus accessing the wrong data. Your loops should go from 0 to width/height, not from x to x + width, resp. y to y + height and using region->rowstride and region->bpp here does not make sense. - You should use g_malloc() or even better g_new() instead of malloc(). This is a nitpick for most platforms but generally good style when working with glib. - You should actually free the allocated memory. - You don't take bpp into account, but then your plug-in only works for GRAYSCALE anyway. - You would do good to allocate a tile cache to speed things up. - Your use of unsigned variables will bite you for small images: unsigned endRow = inputDrawable->height - (unsigned) WINDOW_SIZE /2; This will give unpleasant results for a height smaller than WINDOW_SIZE/2. Well, lots of plug-ins have these problems with very small images and simply using a signed variables doesn't solve the problem (but probably makes it more obvious). Salut, Sven
