Instead they are depending on an undocumented application extension in the first frame of GIF file. Affected browsers are Opera, IE, and Chrome (didn't test others).Īfter some investigation on the matter (by comparing looping and non-looping images), I found out that these browsers' GIF decoders are ignoring the looping parameters in GIF files. The GIF is completely fine the problem is on a modern internet browser's side. I found out the solution for this just yesterday. Using Gfortran, with -O2 optimisation.I was facing the same problem with my GIF encoder/decoder class I wrote some time ago (and improving from time to time).
While thinking about this, I wondered: The loop is fairly big (searches some big arrays, does some calculations, works out an energy in a Monte Carlo simulation, that sort of thing) and so since this starry thing is the only screen output, I was wondering - how much does it cost in runtime?
‘achar(13)’ also works but only if you want to return to the beginning of the line and overwrite everything. So all that this does is write an ‘achar(8)’ character to make the output backspace, use “advance=’no'” to avoid adding a line return, and use ‘mod’ to run through the four characters in the array over and over again. You know how in some text-based programs the fact that it has not completely locked up is shown by having little rotating bar, made just by printing |, /, -, and \ in the same place one after the other? Well, this is one way to do it in Fortran (note, just a snippet, not a working program): ! declare array 'star()' This was made using gifsicle.īut I thought that was ugly, so I’ve got something much nicer now. Got a Fortran program that does some numerical work and I just have it outputting a single character (‘-‘) to the screen each cycle, so I know it’s ticking along. I am not embedding an example because the files are too big and I don’t want to waste your bandwidth and mine. It is usually a lot easier if files are named ‘ p00001.ps‘ to ‘ p99999.ps‘ than ‘ p1.ps‘ to ‘ p99999.ps‘. Okay, so this is reading in PNM files, and note the wildcard format for the filenames, which is why I chose such a simple input filename format, and with a fixed number of characters. Let’s have a look at that magical incantation: PATTERN IBBPBBPBBPBBPBB Then I run gifsicle and produce my animated GIF, and I run ppmtompeg, which takes its input from mpeg.inp. I use two loops and keep all the intermediate files, for no good reason. So what happens here is that I convert all the PostScript files to encapsulated PostScript, then I convert them to GIF and also to PNM. Gifsicle -delay=10 -loop *.gif > myanimatedgif.gif Here is my script, movieB.sh: for f in *.ps Now, the subroutine outputs them as PostScript files, so first I do some conversions. Let’s say all my files have names of the form pXXXXX.ps, where XXXXX goes from 00001 to 99999. Systematic naming of the input files is very important. But what if I want to make a movie? Well, there are two tools that I use for this, gifsicle and ppmtompeg. So I can draw simple diagrams easily enough. These routines are just old Fortran 77 subroutines, and I have bunged them up on the web for reference and because they are still kind of useful. This is a problem for me because I am not really into computer graphics and the like - my scientific programming is all done in a text-based interface, with text files as inputs and outputs, and I do not have the time to spend learning GUI programming.īut, I do have some old PostScript routines that I use for printing stuff out when I have a simulation that is highly geometric in nature, for example something that involves atomic coordinates. As datasets get bigger and more and more imaging and modelling is done in three dimensions, being able to represent data graphically is more and more important. I’m not talking science fiction, but actual science.
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