Episode 175: Polygonal Blob

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After a visit to Libre Graphics World with a report about the state of GIMP 2.8 and a look into the future.

I tackle a question I was asked at the 28c3. Is there a way to draw geometric figures in GIMP? Well, I found three.

The selection tools provide a variety of ways to make a geometric selection which later can be stroked or filled with a colour or pattern. The paths tool can be handy too, I didn’t cover it in this show.

The Gfig plugin allows the construction and editing of such figures, but there are a lot of drawbacks and some risk of fatal crashes.

And finally – is GIMP the right tool? Why not take Inkscape, dabble a bit and export the result to GIMP? Inkscape is easy to use for simple tasks – they have a really good user interface. For more complicated stuff there are the tutorials at screencasters.com. Long time no show there, but perhaps Richard and heathenx can be pestered into making some more. They haven’t given up but gone into hibernation a bit.

And if you are in or around Toronto – Steve Czajka is holding an interesting course there.


00:40 State of GIMP 2.8 – http://libregraphicsworld.org/
01:55 28c3 in Berlin
02:30 Drawing geometric figures – a missing feature?
03:30 Select and stroke
03:35 Rectangle, Ellipse and Free Hand selection tool
04:15 Help from Guides and the Grid
05:00 Stroke
05:50 Combining selections
06:20 Subtracting selections
07:10 gfig plugin
07:30 Lines,rectangles, circles, arcs, polygons, stars and more
08:10 Limits and drawbacks
09:00 Editing
11:00 CRASH!!!!
11:30 Don’t use GIMP! Use Inkscape!
15:30 Getting the work back to GIMP.
16:00 Making a colour transparent
17:00 Choose the right tool
18:00 Version control for GIMP – not yet

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort and Philippe Demartin is licensed under a Creative Commons Attribution-Share Alike 3.0 Germany License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

29 thoughts on “Episode 175: Polygonal Blob

  1. Must be a telepathy Rolf… I was using the exact same method to draw a red circle not longer then 2 – 3 days ago. Ellipse select tool + stroke selection ;). Works like a charm! 😉

    Gfig is still buggy in Gimp 2.7.5 compiled barely 3 days ago. You cannot choose the brush alright but it does not crash for me when closing the window. it’s a very cool feature. I bet that they will have it fixed before Gimp 2.8.x comes out or at least I do hope so ;).



  2. Hi Rolf,
    Great Podcast! I have been using Inkscape for a while and I am highly impressed with the package. I use Inkscape 0.47 and GIMP 2.6.

    You have uncovered a new feature – copy paste between the packages. This must be at 2.7 or 0.48. I can not copy from Inkscape and Paste into GIMP at my version. My workflow is to save the Inkscape project in the native SVG format, and then simply open it in GIMP. GIMP 2.6 can open SVG files and will provide you a preview and ask you to scale it and what resolution you want. You will also not have to remove the white background. It was very smart of GIMP developers to do this.

    I was blown away by the non-linear editing video that was posted. WOW this will dramatically improve the digital arts process.

    Thanks for promoting the course. The course is run by a non-profit guild that I belong to called: Calligraphic Arts Guild of Toronto. Their website is at: http://cagt.posterous.com. It should be a fun day!


    • The working copy&paste is mainly due to fixes in gtk (even though these were driven by the Gimp and Inkscape developers). If you used drag&drop this already worked before, but the xclipboard implementation of gtk had some issues.
      As a side effect this also fixes the behavior when using both programs in KDE.

  3. From Libre Graphics World
    “This plan is being revised now, and it’s quite possible that the team won’t wait for high bit depth support to be finished to release GIMP 3.0. This is because GTK+2 is broken beyond repair with regards to advanced input devices, and GIMP 2.8/2.10 are going to have a broken support for Wacom tablets.”

    This is awesome, broken support for Wacom tablets. PS and PSP X4 are really bad, because they support Wacom tablets. What photographer wouldn’t want to use Linux as a platform and the new Gimp 2.8 with it’s broken support of Wacom tablets. No one uses Wacom tablets!, or needs to. Should just throw mine in the trash. And I can wait another 2 years for high bit color depth with Gimp 4.0. Who needs it, not even professionals, or prosumers use high bit color depth. I cannot for the life of me figure out why PS and PSP X4 support over 8 bit. Even DigiKam supports higher bit color depth. Can’t figure that one out. With broken support for Wacom tablets, and 8 bit only color support for the up and coming Gimp 2.8 and Gimp 3.0. These should be stellar releases. Who needs Photoshop!.

    • Chill out, dude. Noone expected GTK+ to break so badly.

      v2.8 is long overdue, with or without Wacom support. It’s time to release it and move forward. With GTK+3 support for tablets will go back.

      • Wacom support for Windows users wasn’t usable for Gimp as well as Inkscape for a long time now. It is documented in the issues list of Inkscape.

        Beneath Inkscape and Gimp I’m using Blender. Bledner seems to be the only open source graphic package, which is alive and is developing incredible fast. Look at the compositor of Blender and compare it with the layers of Gimp.

        What’ bothering me is, that no one of the remaining Gimp developers seems to be able or willing to look into the Blender code. Wacom support in Blender is working fine for all platforms. It’s not a crime to borrow some good code.

      • I disagree. We were waiting so long for gimp 2.8 we can wait bit longer… 2.6.x is very mature and stable. If You want to do some testing – try compiling 2.7.x… The biggest mistake would be to release something broken after all this waiting.



        • Andrzej, please make an effort of reading what you are commenting on.

          GTK+2 is broken beyond repair. Period.

          Do you disagree with that? Then patch it. I’ll be more than happy if you do 🙂

          • I know what I was commenting on Dude. Chillax. I was commenting on this:

            “v2.8 is long overdue, with or without Wacom support. It’s time to release it and move forward. With GTK+3 support for tablets will go back.”

            I don’t think the should “release it and move forward”. I think that they should not rush it and that’s what I have stated.

            No need to get excited / passive aggressive.


    • It’s not as if tablets are not supported. Just ask Rolf, he uses a Wacom tablet and as you can see in show it _does_ work.
      Problem is that the input handling of gtk+2 is very old and hasn’t changed since 2.0, and can’t change due to compatibility reasons. So not everything today’s tablets provide can be handled, e.g. distance information (how far the pen is above the tablet) and more than one tilt axis. Also, if both ends of the pen have different pressure sensitivities it will lead to errors. Most crucial issue is the higher resolution and the higher position update interval (more than 1024 events per second) that can lead to “missing events”, e.g. the pointer won’t keep up with the pen.
      Many distributions, especially enduser oriented ones, therefore ship patched gtk+ versions and programs, even with the real danger or breaking third party programs (that’s no issue if you build them yourself as this is handled via macros during compiling). And for developers it’s more work as patched versions behave differently, making backtraces hard to use.
      All of this is solved in gtk+ 3 or can be solved later on without breaking compatibility. That’s why the developers push so hard to get to Gimp 3.0 as early as possible even with missing features, it would make everyone’s live easier.
      If you desperately need the high bit depth in Gimp you can either try out the high bit depth git branch (this is already gtk3 so you need to have that installed) or look in the wiki for tricks on how to circumvent some of the 8bit issues. You could, of course, also use a different program like Cinepaint or Krita.

      • Er, just a few minor corrections, if you don’t mind 🙂

        Problem is that the input handling of gtk+2 is very old and hasn’t changed since 2.0, and can’t change due to compatibility reasons. So not everything today’s tablets provide can be handled, e.g. distance information (how far the pen is above the tablet) and more than one tilt axis.

        People mostly complain about lack of pressure support. I’m one of them _and_ I have a Graphire 3 which is, ugh, lemme see, yes — 7 years old. So it’s not about some new hardware.

        If you desperately need the high bit depth in Gimp you can either try out the high bit depth git branch (this is already gtk3 so you need to have that installed)

        This bit is rather misleading too. 1) the hbd branch doesn’t really do much, so there is nothing to try, and 2) it’s forked from Git master which is gtk+2.

        • I’m using a Bamboo One (not mine, sadly) and pressure recognition does work. With the pen or brush you can set it to opacity, diameter or another parameter to alter. Rolf showed this as well in episode 101 and he uses an Intuos he also has for some years by now. I don’t know about the Graphire, never used one before.

          I was not talking about the rebased high bit depth branch, never gotten that to build, but the failed soc 2011 float branch. It was/is based on the not finished gtk3 port back then and will still compile with gtk2 (at least it did back in december) but it won’t run. Cost me some hours to figure that out.

          Still, I think the current way the developers go makes the most sense. The, obviously, know the code best and this keeps Gimp running and being useful while porting is going on. This is also the difference to Cinepaint, which has a new core, but not nearly as many third party plugins are available as for Gimp. The Gimp way keeps all of them running, even though large parts of Gimp have already been ported to gegl and been prepared to switch to gtk3.
          I expect, as soon as 3.0 development cycle starts, that most plugins, scripts and functions will be broken for months due to api changes, something that has not happened for many years by now in the Gimp 2.x lifetime.

          • “the failed soc 2011 float branch” — it seems to me that you certainly know way more than me, because there have been no failed GSoC projects in 2011. Do you think you could just link to the branch you have in mind? That would spare us all the unnecessary unpleasentness 🙂

            Yes, further intrusion of GEGL is likely to break a lot of things, but guess what… things break anyway. 2.7.x has undergone some major API changes that already break quite a few plug-ins and scripts.

  4. You’re missing so many technical and cultural points that I don’t even know what to begin with when explaining what exactly you get wrong. Perhaps “everything” would be the most appropriate reply.

    I’m fine about eloborating on that, but I don’t want my explanation to fall on deaf ears, and it’s sooo likely to be the case.

    • I assume this was a reply to Christoph and not to my blog post or video. 😉

      Taking code from Blender sounds easy and logical. But this is a bit like pulling a carburetor out of an US car and fit it into a German one. Doesn’t work, wrong dimensions, wrong set of references.

      • Doh, my bad 🙂 Indeed I was repying to Chrostoph.

        And yes, pulling code from Blender makes no sense whatsoever. Especially since everything works in GTK+3 anyway.

  5. From what I have read, I like the idea of Gimp being turned over to a Foundation model. Like Blender and LibreOffice. We need a Gimp foundation. The current model isn’t working. Lack of developers etc.. I got an email from Corel, in my reply to thanking them for supporting Linux in AfterShot. I asked them about PaintShop Pro being ported to Linux, but unfortunately, they are still a bit hesitant. They need allot more feedback from Linux users in order to think about possibly porting the application. Would also be nice if Picasa could be natively ported, without having to use Wine. Gimp is fine, but we need more options, and more secure options. My input.

  6. Way cool episode! I have tried, and mostly failed, to use Gimp for drawing shapes, now I am inspired to try again. Also I didn’t know that you could now cup/paste from Inkscape to Gimp, again very helpful information.

  7. Sorry for living. But I think it will not help to make Gimp more popular to tell people, who find that the software has flaws, to fetch some development branch and try this. In fact I could do this as a professional software developer, but I want a Gimp as a tool to manipulate photos and not as a playground to refresh knowledge about C-development.
    I know, this is hard to accept for you guys, but my main machine runs under Windows 7. For this operating system it is a fact that there never was a stable support for tablets and it was getting worse over time. You have to follow a certain sequence of steps to configure Gitk 2 for tablets every time you fire up Gimp.
    And of cause it makes sense to have a look into software that already solves a problem when you have trouble to fix something.
    This is a big problem in software development that people always try to figure things out on their own. Back when I was doing chemistry before I did a new experiment I went into the library and read for days about the experience other people had with this topic. In software development most people think they are cheating when they don’t invent the wheel again and again. Of cause you should start to work on your own wheel, if it should be square. In shops you’ll only find the round ones.

    • There is nothing difficult about accepting that most of ther user base is on Windows.

      There is also nothing difficult about understanding that GIMP had support for tablets long before Blender was even made public.

      And of course there is nothing difficult about saving status of input devices across sessions. This is exactly how it’s been working since forever. Whether it’s broken on Windows is an entirely different matter.

      Pretty please do some basic facts checking 🙂

    • Maybe Gimp just isn’t the right tool for you.
      When I was a kid I took apart one of my dad’s drills to find out, why it didn’t work anymore. I don’t remember what was broken but I put it back together and it still works today.
      I guess that attitude has stuck with me and is the reason I left the dos/windows world many years ago (around the time of windows 3).
      While for you Gimp is just an end-user program to edit images, for quite a lot of people it _is_ a development platform to test out new graphics algorithms and tools. Examples are siox, the resynthesizer, the cage transform tool and different wavelet plugins as well as the gegl framework. Another example is Cinepaint, which is also a Gimp offspring and some of its experiences have migrated back to Gimp in the form of GAP.
      Developing for windows is always a form of blackbox work if you don’t have the money to pay for a look at the internals. And this means errors are common (and intended, to keep the money flowing).
      If you program on Linux or BSD you can look at the sources to see how it’s handled and use a debugger to step through the whole stack. You can look up how tablet events are handled by the usb subsystem and the x server and how they reach gtk+ and are finally used in Gimp. On windows, you’re on your own.

  8. I thinks it’s best to throw in the towel on Gimp development. Pretty much has turned into a failed project. Gimp as the premiere pixel editor for Linux is over. This just proves it. Who needs a broken and boring product. With old technology. Two long years to get a few basic addons, and not the technologies that really matter. Like high bit depth color support, adjustment layers (rather have that than layer groups), and a “modern” looking user interface. Single window mode looks like it was just thrown together with same 5 year old icons etc.. This product has a modern and polished user interface. http://www.dpreview.com/news/2012/01/25/DxO_OpticsPro_7p2. Take a good look developers!. And wow they threw in “one” whole new gradient. Brilliant!.

    • Oh cool, this is developing into a flame…. 😉

      Jim, you haven’t understood the nature of an Open Source Project. It’s not driven by customer pressure, it’s driven by the vision of the developers. They do what they want when they want. It’s their’s and they SHARE it with you for free. Take it or leave it in the digital gutter.

      You can contribute by taking up some of the work, give money, educate others and perhaps some other ways too. If yo have a proposal for a feature, be prepared to invest some time into it, do the research, make a mock up, write a detailed description, discuss it with the developers. And be aware that they are entitled to dismiss your idea and you are not entitled to complain. You may take the code and fork it – no problem. But you are in no position to tell them what to do. And you are in no way in a position to declare it a failed project.

      The “modern” look – get the icon set, do a new one. It’s really easy to change and integrate. You need only to be able to paint a bit in GIMP. But be prepared for some critique. You will have to come up against some serious amount of thoughts that poured into the design of the “old” icon set. It’s a balance between uniform look, ease of recognition and low distraction. I lurked on the mailing list while there was a bit of this discussion. And if you meant the dark look as modern – just switch to it with your current GIMP in the GTK settings.

      The link you provided points to a program that sets you back at least 100€. And that after a 30% limited time rebate that ended Dec 24th. Double price for the “Elite Version”. Read the comments under the article, more complaints than praise. GIMP has a 100% rebate, all the time and you even get the “Elite Version” with no added price.

      It’s a bit like with these videos. I do them, I share them with you. You can watch them, ignore them, comment them, critique them, thank me for them, help me (reminds me – I have to put the hat for the server costs on the pavement again), send me presents, blog about them, share them with others, dub them, modify them, add captions in Cantonese, give me input for topics ….. but you can’t *demand* that or when I do another one or what’s in there. That’s my call. Because I do this and SHARE it.

  9. Some advice Jim. Dualboot if you have Linux installed!. Than you can have the best of both worlds. Even MacOSX users have MacOSX and Windows installed together, via bootcamp. Nice episode Rolf!.

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