GIMP 2.9.4 and our vision for GIMP future

So you may have heard the news: we recently released a new development version of GIMP, version 2.9.4 (as well as a bugfix release 2.8.18, but this is not as awesome).

Small edit: I realized that my blog post has been linked on many major news website. I didn’t expect this! Therefore I just want to make clear that whatever I wrote below is my view of GIMP future. It may not be shared by other developers who have their own priorities and this post has not be written with the other devs. In other word, anything here is not written as anything official from the GIMP project itself, but from me only, a single contributor to GIMP.

GIMP 2.9.4

I am not going to rewrite all of the official news, because you may as well read it on gimp.org. Anyway I co-wrote the news with the rest of the team and provided several screenshots. So reading there is also partly same as reading here. 😉

I’ll just illustrate with this cool picture of the live preview of operations (here a gaussian blur) directly on canvas, split for comparison, implemented by Mitch, our own benevolent dictator (or are we all his dictators?). The image on canvas is by Aryeom, ZeMarmot‘s director.

GIMP 2.9.4 screenshot. Image on canvas is by Aryeom Han under Creative Commons by-sa.
GIMP 2.9.4 screenshot. Canvas image by Aryeom Han (Creative Commons by-sa).

Pretty cool feature, uh?

GIMP & ZeMarmot project

As you can read on gimp.org, ZeMarmot is a contributor to GIMP through my own contributions (which amounts to about 14% of commits for this specific release. Commits number is not always the most perfect metrics but as good as any).

Painting

So what did we bring to the table? Well there are the stuff which we like most first: painting. So I developed symmetry painting last year. Here are some symmetrical doodles drawn by Aryeom in just a few seconds, thanks to the symmetry modes:

Symmetrical doodles by Aryeom Han (Creative Commons by-sa).
Symmetrical doodles by Aryeom (Creative Commons by-sa).

I also helped on the integration of the MyPaint brushes, and in particular contributed upstream on a whole build system rework which, as a side effect improved the codebases of libmypaint and MyPaint (quote from Mypaint’s blog post):

Development of MyPaint will continue of course; in fact making this split happen has improved a lot of things in the codebases of both projects ☺ Big thanks to @Jehan for making this all work so well!

Internationalization

Also the fact that Aryeom is Korean, that we both lived in several countries in Europe, Asia and Oceania, that we speak English, French, Japanese, Korean (well my Korean is lacking!), and that I love languages and am a grammar geek made us good targets to notice anything wrong with GIMP’s support of non Western languages. So I have fixed some bugs and even crashes related to Input Methods and made the text tool finally compliant with input method engines (it used to have an ugly overlay box, not integrated at all in the input box, and without any standard formating).

Writing Korean (left) or Japanese (right) in GIMP 2.9.4's text tool.
Writing Korean (left) or Japanese (right) in GIMP 2.9.4’s text tool.

Of course, I did several other fixes related to languages since I contribute to GIMP like each language translated in itself in the list of language in the preference, or bugs with GUI with right-to-left languages, like Arabic (did I say I was a language geek? I love all these differences and particularities).
Other than this, both Aryeom and I are trying to build a more diverse community by engaging FLOSS and GIMP enthusiasts in Japan, South Korea (some tutorial videos in Korean even) or other countries in their native languages. A hard and long job but we are trying. 🙂

Code review and code maintenance

Well I code a lot of other stuff, smaller features (like the email plugin in GIMP 2.9.4, using xdg-email, implemented a few weeks ago) and bug fixes since I like GIMP hard-rock solid and as stable as possible but that’s obviously less visible. I am also trying to step up more and more for code review and maintenance of small pieces of the software, since Mitch really needs the help (apparently the whip is not enough help! Go figure!). Well this is still work in progress and I wish I could make time to bring more cool code into GIMP, but it still allowed the action search (equivalent to the space-menu of Blender), which I think is one of the coolest feature of GIMP 2.9/2.10 and making menus so old school. This was originally contributed by Srihari, then I reviewed, rewrote and fixed parts of it to fit our high standards on code quality. Well I think that’s one of the features I am the most proud as a reviewer (instead of as the original author). This is also very rewarding to work with other coders, especially when talented and with interesting ideas.

Searching an operation in GIMP with the action search.
Searching an operation in GIMP with the action search.

There are more code I reviewed and integrated, like lately the cool command line’s batch processing macro or even the whole revamping of the user interface (new themes and icons). Arguably this is less “useful”. Well it depends. I met some people who claimed it will change their life, while others would hate the new design direction (though note that old icons and theme are still available in preferences). But anyway this was an idea hanging around on mailing list for years, so I took on myself to attend to new contributors willing to help on the matter (Klaus Staedtler for the icons and Benoit Touchette for the themes). This is also an interesting adventure, I think.

New themes by Benoit Touchette and icons originally by Barbara Muraus and Jakub Steiner, heavily updated and completed by Klaus Staedtler.
New themes by Benoit Touchette and icons originally by Barbara Muraus and Jakub Steiner, heavily updated and completed by Klaus Staedtler.

In the end working on all these fronts is very cool but also exhausting. Hopefully the more time goes, the more I will be able to do! 🙂

Future of GIMP

GEGL everywhere?

I see a lot of good things happening around GIMP. And not just from me, but from all the awesome people in GIMP team and projects around. GEGL for one is a hell of a cool project and I think it could be the future of Free and Open Source image processing. I want to imagine a future where most big graphics program integrates GEGL, where Blender for instance would have GEGL as the new implementation of nodes, with image processing graphs which can be exchanged between programs, where darktable would share buffers with GIMP so that images can be edited in one program and updated in real time in the other, and so on.
Well of course the short/mid-term improvements will be non-destructive editing with live preview on high bit depth images, and that’s already awesomely cool right?

Painting again, better UI, export and much more…

Of course we want to go further for painting features and workflow improvement, but also the UI which really needs some reworking here and there (which is also why I created the gimp-gui mailing list, meant to discuss all sort of topics UI and UX related). That also includes improving support for graphics tablet and alike.
I also have a lot of ideas, some may come to be implemented in a form or another, or not (the export process for instance is still untouched for now). Even when this happens, it’s ok: contributing to Free Software is not just adding any random feature, that’s also about discussing, discovering others’ workflow, comparing, sometimes even compromising or realizing that our ideas are not always perfect. This is part of the process and actually a pretty good mental builder. In any case we will work hard for a better GIMP. 🙂
Among the many other features we are really keen on are the ability to select many layers at once (this is often a pain for Aryeom, since she usually works with many dozens of layers when animating), macros, improving the API to be able to customize the GUI (and not only adding menu items) and the behavior of GIMP, get more communication between GIMP and plugins and in general reacting to hooks, and much much more.
Now there are stuff which are also cool, like better HiDPI support but since we don’t own a HiDPI screen anyway, this is harder to test.

Also I like GIMP for being generic. While other programs choose to be specialized, which is a valid choice, we can notice most graphics programs end up with the same features in the end anyway. Indeed brushes and other painting features are actually very useful to photographers as well. On the other hand, painters regularly use filters and transformation tools originally thought for photographers. Designers use everything as well. So I think the approach of a program which aims to do everything well is quite acceptable too.

Well you see, we have a lot of plans about GIMP, that seems nearly impossible but that’s exciting. And of course, there are the plugins for animation that I am working on, on a good pace. I think I will be able to present the main GIMP plugin for animation quite soon on this website. Stay tuned! 🙂

Help us by helping ZeMarmot?

As often, I will conclude by promoting our permanent monthly funding of ZeMarmot. I know this is very annoying! We want to make a difference, something cool: a Libre animation film together with Free Software code. And trying to make this into more than just a hobby. Right now we are barely there.
I regularly talk about the more “artistic” side here, not often enough about the “technical” coding side. So I decided to use the opportunity of GIMP 2.9.4 release to make this small (non exhaustive) report of stuff I had been doing these last months and what are our goals on the software side (GIMP in particular). If you like what you read here about my contributions, then you like what ZeMarmot is doing, because this is all the same project. And therefore if ever you can afford it, we would welcome financial help so that we can continue software development as well as the production of the animation film.

We are on 2 platforms allowing monthly subscription (which you can stop anytime, as soon as you don’t like us anymore!): Tipeee where you can contribute in EUR (€) and Patreon where you can contribute in USD ($). Note that our pitch is written in French on Tipeee but that’s the same project anyway. Just read the official website in English or the Patreon page.

ZeMarmot on Tipeee (EUR).
Support ZeMarmot on Tipeee (EUR) »
ZeMarmot on Patreon.
Support ZeMarmot on Patreon »

That’s it for today! I hope you enjoyed my coding report on GIMP. Enjoy your week-end everyone! 🙂

crossroad 0.6 released: cross-building GIMP as an example

Hello all!

TL;DR; if you don't care at all about how crossroad works,
and you just want to cross-build GIMP in a few commands,
see at the bottom of the article.

Over the years, I have written a tool to cross-compile software under a GNU/Linux OS for other targets: crossroad. Well to this day, the only supported targets are Windows 32/64-bit. I realized I never advertised this tool much which — even though it has been originally built to help me build and hack a specific project (GIMP) — ended up as a generic cross-compilation system for Linux.

“The crossroads” where Robert Johnson supposedly sold his soul to the Devil, by Joe Mazzola (CC by-sa 2.0)

So today, I will explain crossroad by giving a concrete example:

Cross-compiling GIMP on GNU/Linux for Windows system

The basics

The cool stuff about crossroad is that it allows to cross-build as easily as a native build. For instance f your build system were the autotools, you would run the famous triptych ./configure && make && make install, right? Well with crossroad, you only wrap the configure step but the rest is the same!
cmake is also fully supported, even though my examples below won’t show it (check out the manual for more).

All what crossroad does is preparing you a suitable environment, with the right environment variables, but also wrappers to various tools (for instance, you get the x86_64-w64-mingw32-pkg-config tool inside a crossroad environment, which is no more than a wrapper to detect packages inside the cross-built prefix only).

Enough chit-chat. Let’s install crossroad!

pip3 install crossroad

Running crossroad the first time

I will now go through a full cross-build of GIMP for Windows 64-bit, from a brand new crossroad install. It may be a little long and boring, but I want to show you a full process. So you can just run:

$ crossroad --list-targets
crossroad, version 0.6
Available targets:

Uninstalled targets:
w32 Windows 32-bit
w64 Windows 64-bit

See details about any target with `crossroad --help <TARGET>`.

Ok so at this point, you may have no cross-compilation compiler installed. Let’s see what I need for Windows 64-bit.

$ crossroad --help w64
w64: Setups a cross-compilation environment for Microsoft Windows operating systems (64-bit).

Not available. Some requirements are missing:
- x86_64-w64-mingw32-gcc [package "gcc-mingw-w64-x86-64"] (missing)
- x86_64-w64-mingw32-ld [package "binutils-mingw-w64-x86-64"] (missing)

The package name was actually based off a Mint or a Mageia, I think. If you use Fedora for instance, you will want to install mingw64-gcc and mingw64-binutils.  Just adapt to your case.

Let’s check the output of crossroad again:

$ crossroad --help w64
w64: Setups a cross-compilation environment for Microsoft Windows operating systems (64-bit).

Installed language list:
- C
Uninstalled language list:
- Ada Common package name providing the feature: gnat-mingw-w64-x86-64
- C++ Common package name providing the feature: g++-mingw-w64-x86-64
- OCaml Common package name providing the feature: mingw-ocaml
- Objective C Common package name providing the feature: gobjc++-mingw-w64-x86-64
- fortran Common package name providing the feature: gfortran-mingw-w64-x86-64

We could stop here, but I actually know some programs make use of the C++ compiler, so let’s also install `mingw64-gcc-c++`. And now we are good to go!
I create a Windows 64-bit cross-build environment, that I will call “gimp-build”:

$ crossroad w64 gimp-build
Creating project "gimp-build" for target w64...
You are now at the crossroads...
Your environment has been set to cross-compile the project 'gimp-build' on Windows 64-bit (w64).
Use `crossroad help` to list available commands and `man crossroad` to get a full documentation of crossroad capabilities.
To exit this cross-compilation environment, simply `exit` the current shell session.

Dependencies

babl

Now let’s cross-build babl! Very easy one to start with because it does not have any dependencies:

$ cd /path/to/src/of/babl/
$ crossroad configure && make && make install

Done! You’ll notice that you don’t even need to specify a prefix. crossroad is taking care of it.

GExiv2

$ cd /path/to/src/of/gexiv2
$ crossroad configure

The configure ends up with a pretty clear error:

checking for GLIB... no
configure: error: GLib is required. Please install it.

Well basically you have to install glib. And then you think: the hell is starting! Do I have to build every dependency by hand? Fortunately no! crossroad relies on the OpenSUSE cross platform builds and can automatically download many dependencies for you. The reason I don’t do it for for all dependencies (babl, GEGL, libmypaint and GExiv2 in this tutorial) is when packages are either too old or non available. Install glib with:

$ crossroad install glib2-devel

That’s all! Neat right? Well you also have to install Exiv2 (trying to run the configure again, you’d see another error. I spare you the wasted time). You can run a separate command, or could have installed them both at the same time:

$ crossroad install glib2-devel libexiv2-devel

Try again:

$ crossroad configure

In the configuration summary, you’ll see that introspection and python bindings won’t be built-in. But since they are not needed for GIMP, we don’t care.

$ make && make install

And now GExiv2 has been cross-built too!

gegl

Now for gegl:

$ cd /path/to/src/of/gegl
$ crossroad configure

Once again, you’ll get a few dependency errors. I spare you the try and fail process. Here are all the other mandatory libs to install:

$ crossroad install libjson-glib json-glib-devel libjpeg8-devel libpng-devel

And for a fuller list of optional dependencies:

$ crossroad install cairo-devel libtiff-devel librsvg-2-2 librsvg-devel pango-devel libwebp5 libwebp-devel libjasper-devel gdk-pixbuf-devel

Well there are actually more dependencies you could install or build yourself, but I don’t think they are really needed for GIMP. I’ll just leave it there. Now I build:

$ make

But then… a build error (I’ll admit: I left a dependency error on purpose!)!

In file included from /usr/include/SDL/SDL_main.h:26:0,
from /usr/include/SDL/SDL.h:30,
from /home/jehan/dev/src/gegl/operations/external/sdl-display.c:35:
/usr/include/SDL/SDL_stdinc.h:74:20: fatal error: iconv.h: No such file or directory
compilation terminated.
Makefile:1277: recipe for target 'sdl_display_la-sdl-display.lo' failed
make[4]: *** [sdl_display_la-sdl-display.lo] Error 1
make[4]: Leaving directory '/home/jehan/dev/crossbuild/w64/gegl/operations/external'[…]

Well that’s a good example to debug. Look well at the paths… /usr/include/[…], they are definitely for the native platform! So something is wrong.
Also I don’t even remember having installed SDL through crossroad anyway. Well if you were to check out the config.log, you would understand why the configure script found it:

configure:22069: checking for sdl-config
configure:22087: found /usr/bin/sdl-config
configure:22100: result: /usr/bin/sdl-config

Sometimes, some projects would use their own *-config script instead of relying on pkg-config (SDL seems to also have a pkg-config file, not sure why we’d prefer usind sdl-config, but well…). And while pkg-config allows to really separate the build and target environments, I can’t remove the current $PATH because a lot of native tools are needed in a cross-compilation. All this to say: you may encounter issues with software distributing custom *-config script. Be warned!

Anyway let’s install SDL, don’t forget to re-run configure (otherwise the native lib will still be used), then build again.

$ crossroad install libSDL-devel && crossroad configure && make && make install

Easy said, easy done.

libmypaint

Only a single dependency (json-c), then classical configure, make, make install:

$ crossroad install libjson-c2 libjson-c-devel && crossroad configure && make && make install

GIMP

And now for the main course! Once again, I spare you some of the search of dependencies. Here for mandatory deps:

$ crossroad install atk-devel gtk2-devel libbz2-1 libbz2-devel liblzma-devel liblcms2-2 liblcms2-devel

I’ll skip completely Python dependencies. This is the only major part of GIMP I’m still having issues with in my cross-builds so I will run configure with --disable-python.

As for optional dependencies:

crossroad install libgs8 libgs-devel libmng1 libmng-devel libpoppler-glib8 libpoppler-glib-devel poppler-data xpm-nox-devel headers iso-codes-devel libwmf-devel


Note 1: libwmf-devel has the same issue as SDL, thus the configure script would see it installed if you have it on your main system because of the libwmf-config in your $PATH.

Note 2: you can use crossroad search to discover package names. Even better, sometimes you know a file name that configure is looking for (after a dependency error, check out the configure.ac file or the config.log file for this info). For instance, I can’t find a libghostcript but I see that GIMP‘s configure is looking for the file ghostscript/iapi.h to detect ghostscript:

$ crossroad search --search-files iapi.h
"iapi.h" not found in any package name.
The following packages have files matching the search "iapi.h":
- headers
- libgs-devel

Then using crossroad list-files libgs-devel, I can confirm that this is the right package (crossroad info libgs-devel also confirms this is the package for Ghostscript development files).


Back to building GIMP:

$ crossroad configure --disable-python
$ make &&
make install

Note that I don’t built some options in, like the Ascii Art, the help browser, or OpenEXR because I could not find prebuilt dependencies, but it should not be hard for you to build the dependencies yourself as we did for babl/GEGL/…

Running under Windows!

And now you can for instance make a zip to put on a Windows, like this:

$ crossroad --compress=gimp-build.zip w64 gimp-build

This will just compress the whole target build, where GIMP for Windows is under bin/gimp-2.9.exe. Now this is *not* an installer or whatever finale. The target directory is full of files useful for building, yet completely useless for the finale installation. crossroad is *not* meant for making installers… to this day at least (saying that I would not be against if anyone wanted to implement something of the sort. Why not?! Send me a patch!).
Since I usually run Windows in a Virtualbox VM, rather than zipping a whole archive, I would simply share a directory and symlink the target directory like this:

$ cd /path/to/dir/shared/with/windows/vm/
$ crossroad --symlink w64 gimp

Note: in your Windows environment, you must update the PATH environment variable to add your build’s bin/ directory otherwise Windows won’t find your various built DLLs. You’ll find information on how to do so everywhere in the web.

I use crossroad as a developer, to test and sometimes patch directly GIMP for Windows, without ever getting out of my Linux OS. Well I still test under a Windows VM, which runs in Linux. But I develop and compile in my GNU/Linux shell.
Hopefully this tool can be useful to other people willing to test their program under Windows while hacking on GNU/Linux.

About having a good build system

If you followed good programming practice, and use a full-featured build system such as autotools and cmake, chances are that you can cross-build your program with barely any fix to the code. This is for instance what happened when I ported GExiv2 to autotools after we started using it in GIMP. GExiv2 maintainer would say in the blog post:

This in turn allows gexiv2 to build on Windows, something we’d not targeted at all when we began development but is obviously a hard requirement for GIMP.

Just having a good build system turn their Linux-only library into a multi-platform one. Pretty cool, no? And now libmypaint got the same fate, I autotooled it making it just so easy to cross-compile!

But if you have hand-made makefiles (like GExiv2 did), a scons build (like libmypaint did), or other build systems which don’t have a proper support for cross-building, this won’t be as easy. Think twice when you set up your software. The tool you use for builds is definitely not something to take lightly!

The one-step crossbuild script

This was all for you to see how crossroad is working. If you are only interested into building GIMP specifically, I compiled my whole tutorial below into a single build script that you are welcome to copy paste and run with crossroad like this:

crossroad install glib2-devel libexiv2-devel libjson-glib json-glib-devel \
  libjpeg8-devel libpng-devel cairo-devel libtiff-devel librsvg-2-2 \
  librsvg-devel pango-devel libwebp5 libwebp-devel libjasper-devel \
  gdk-pixbuf-devel libSDL-devel libjson-c2 libjson-c-devel atk-devel \
  gtk2-devel libbz2-1 libbz2-devel liblzma-devel liblcms2-2 \
  liblcms2-devel libgs8 libgs-devel libmng1 libmng-devel \
  libpoppler-glib8 libpoppler-glib-devel poppler-data \
  xpm-nox-devel headers iso-codes-devel libwmf-devel headers
git clone git://git.gnome.org/babl
cd babl && crossroad configure && make && make install && cd ..
git clone git://git.gnome.org/gegl
cd gegl && crossroad configure && make && make install && cd ..
git clone git://git.gnome.org/gexiv2
cd gexiv2 && crossroad configure && make && make install && cd ..
git clone https://github.com/mypaint/libmypaint.git
cd libmypaint && crossroad configure && make && make install && cd ..
git clone git://git.gnome.org/gimp
cd gimp && crossroad configure --disable-python && make && make install

If you copy these into a file, say build-gimp.sh, you can run it at once with:

$ crossroad w64 gimp-build --run build-gimp.sh -n

I hope you enjoyed this tutorial on how to build GIMP with crossroad!

Note: if you like what I do, consider sponsoring our
animation film (CC by-sa), made with GIMP: ZeMarmot!
We fund it with Patreon (USD) and Tipeee (EUR).

Improving the export process in GIMP

While I have been working for days on the animation software for ZeMarmot, I wanted to “rest” my brain a little and came back to an old project of mine, which I should have implemented months ago.

So let’s get the troll out straight away: yes, this is about the split between save and export on GIMP. Now I was not there when the decision was taken, but I think it makes sense anyway. Saving is about “your work”, your process. XCF is — in such a view — not an image format, but a project format. It contains much more than the final visual image. Same as you would not save a “.mpeg“, “.avi” or “.mov” in blender, but a “.blend“, you don’t save a “.jpeg” or “.png” either, but a “.xcf” (another analogy for developers out there: “.blend” or “.xcf” can be compared to your source files — which is definitely what they are in a multimedia project — and the image or video formats as the compiled binary).

Yet I understand that some users have a hard time understanding this since there are nearly no difference in our GUI between saving and exporting.
save-export
What’s the difference, you’d ask? And you’d be right.

In the last 2 days, I refactored the whole GimpFileDialog code, which was completely mixing every concepts with hard-to-read if {} else {} statements inside a single class. GimpFileDialog became a generic parent class, containing only logics common to all file dialogs, and I added 3 specific children: GimpOpenDialog, GimpSaveDialog and GimpExportDialog.
This will allow us to do easily much more interesting graphical interfaces specific to each process.

As a proof of concept, I tested a “Scale at export” feature, which would allow to rescale images at export time, without touching the original. Who indeed never worked on some high resolution image, then needed to export it in lower resolution (to upload on some website, send through email or whatever…)? The current GUI would force to scale the original image, export it, then not forget to cancel the scale afterwards (if you forget, save and quit — for instance by habits — you are doomed: you just completely lost data and hours of high res work!).
Here for a UI test:
Scale for export in GIMP

Now before you tell anything: I know that the above screenshot does not look so nice, with a lot of wasted space on the right. I reused an existing widget (the same used in the “Scale Image” dialog, if you know GIMP well) and have not been trying to customize for this first version. The goal was mostly to test the new refactored code and we have some more thinking and discussion before actually adding these features (there are many more things that could be rethought to improve export, at deeper levels too).
The refactoring is now merged to master; the “Scale at export” isn’t yet though (feel free to test it on its git feature branch though, it’s functional).

Of course this is only the start of greater things. One may want to crop an image, change the color space (particularly if you were working in non sRGB), or even apply any GEGL operation before export (like “sharpen” after downscaling).
This should all be possible soon. Of course we’d have to work on the ideal UI to not clutter the export dialog. I will keep readers updated for when the next steps will occur.

I believe this is partially what some people would call a “Save for Web” feature, though I personally don’t like this naming since it is far too restrictive. You may want to change your exported image for far many more reasons that just “the web”.

Now I’ll be back to ZeMarmot (and I remind everyone who wants to support me to improve GIMP they can still support our Open Animation Film)!