The (directed) graphs represent finite automata. Up until now my test program has been writing out dot files for testing. This is pretty good both for regression testing (keep the verified output files in subversion, ask it if there has been a change) and for visualisation. However, there are some problems...
Basically, I want something callable from C++ and which plans a layout for my states and transitions but leaves the drawing to me - something that will allow me to draw things however I want and draw on GUI (wxWidgets) windows.
I also want a license which will allow commercial use - I don't need that at present, and I may very well release as open source, but I don't want to limit my options ATM.
The problems with GraphViz are (1) the warnings about building from source on Windows, (2) all the unnecessary dependencies for rendering and parsing, and (3) the (presumed) lack of a documented API specifically and purely for layout.
Basically, I want to be able to specify my states (with bounding rectangle sizes) and transitions, and read out positions for the states and waypoints for each transition, then draw based on those co-ordinates myself. I haven't really figured out how annotations on transitions should be handled, but there should be some kind of provision for specifying bounding-box-sizes for those, associating them with transitions, and reading out positions.
Does anyone know of a library that can handle those requirements?
I'm not necessarily against implementing something for myself, but in this case I'd rather avoid it if possible.
Hmm, GDToolkit (or GDT) looks okay: many of the images in the tutorial look pretty nice, and it doesn't look like it's terribly complicated to use.
Edit: But checking the license, it looks like it's commercial software :-(. Whoops!
OGDF is under the GPL.
Pigale is also under the GPL.
GoVisual is commercial software, but it looks like it starts at $1800 for one developer.
I was dealing with a similar problem earlier this year. One important input parameter for a decision however is the expected number of nodes.
I decided to use the Browser as the GUI and therefore looked for nice Javascript libraries, one i came across was wireit, it is very well suited for technical layouts (and also editing with drag and drop and "on the fly" layouting). You could easily connect that to your c++ by running a small webserver in a thread (You will need some kind of eventloop/thread thingie for GUI anyways).
Well just my 2 cents.
Although the answers so far were worth an upvote, I can't really accept any of them. I've still been searching, though.
One thing I found is AGLO. The code is GPL v1, but there are papers that describe the algorithms, so it should be easy enough to re-implement from scratch if necessary.
There's also the paper by Gansner, Koutsofios, North and Vo - "A Technique for Drawing Directed Graphs" - available from here on the Graphviz site.
I've also been looking closely at the BSD-licensed (but Java) JGraph.
One way or the other, it looks like I might be re-implementing the wheel, if not actually re-inventing it.
Here is a good collection of Graph Libs with comparison and searching functionality:
http://gvsr.polytech.univ-nantes.fr/GVSR/task?action=browse#
Maybe you find a lib which fits for you.
Related
I am attempting to build a small local-purpose 3d engine, which has to be platform-independent and right now I'm looking for a way to handle different possible types of user input.
This, obviously, includes mouse / keyboard events and possibly, another analogue controllers (joysticks, for example). I can think of several ways to implement this and am seeking for an advice - what would be better.
So far, I can write my own controller event handling and dispatching module, reimplement the whole functionality myself, though I guess I would face some troubles making this work for different platforms and integrating it. That's the hardest and the reinventing way.
Another approach would mean reusing some existing scheme / library for this sort of things, but I can't come with a good choice. Qt seems like an overkill for my small library, allegro and other SDL-like libraries have pretty tight logic coupling and writing a generic wrapper around them could become even harder then rewriting everything from scratch.
Maybe there is some appropriate library, which could help me in this situation?
What would you do?
Thank you.
OIS is pretty good. It's the default one that the OGRE tutorials use.
I want to implement a paint-like application, which will enable kids to create and work with 3 dimensional objects.
How can I start?
What is the right approach? WPF, OpenGL, or Direct3D?
(I prefer C# solutions, but C++ is OK also).
Thank you all in advance!
--NewB
Here is an excellent example using WPF you could start with:
http://www.codeproject.com/KB/WPF/Wpf3DPrimer.aspx
However, you should definitely keep an open mind and consider some other possibilities. Because there are actually lots of different ways of doing this sort of thing, all of them with their own relative costs and benefits. It's kind of like ice cream - WPF is probably like chocolate, although that might be too strong a statement.
Just as a note, you may wish to take a look at XNA too - it's a nice API that wraps up a lot of the more complex Direct3D bits and bobs and allows you to jump right in there, it's also for use with C#
I'd skip all of the above, and use a higher-level API like MOGRE or osgDotNet. These will let you switch between DirectX and OpenGL relatively painlessly, and semi-automatically optimize the drawing, as well as supporting quite a few features that will be quite a bit of work to do entirely on your own. You may never need the extra features, but then again you might -- and with these they're more or less thrown in for free.
I would like to know what do you use to sketch relations between different entities in C/C++. This can be a very broad issue, so I'll try to clarify a bit more my question and give an example.
I'm looking for something that is simple enough as a user, and let me sketch easily containers, pointers, etc... in an informal way.
The aim is to document some structs relations to pass them to junior developers. A look at the drawings is supposed to accelerate the understanding of the code.
My solutions at this moment are to use:
1) Paper & pencil.
2) Microsoft PowerPoint/Word Autoshapes.
3) Freeware Dia.
Other ones could be:
4) Microsoft Visio, but my company does not own licenses.
5) UML tools. I don't want to go this way. This is what I mean a more formal solution.
I know tools like Rational Rose are xxx, and I tried boUML and violet and they are fine in some parts, but I prefer the flexibility of options 1), 2) or 3).
Finally, let me write down a more concrete example:
Let's say I what to sketch a map that contains another map as the mapped value, and that one contains a struct as the mapped value, that holds a vector of pointers of a type and a pointer to other type. Also, there exist other structs that hold pointers to the objects pointed by the previous map, so there are objects pointed from different places.
This is just one example I have, but you can easily come with one from you experience.
What would you use to sketch this example or another similar you have dealt with?
Best regards,
Tomas.
Visio is great for quickly creating these types of illustrations / diagrams. I recommend at least trying to get your company to purchase a license.
If Visio is truly not an option for you, the next step may be to consider Open Source alternatives to Visio.
I have two things I use.
My whiteboard. Whiteboards are really tough to beat for diagramming something quickly.
UMLPad. It's small, so it doesn't have a ton of unrelated features to deal with, it is targeted to UML diagrams, and it is GPL.
For design issues, involving thoughts by a good many people, we've used "Post-It Design". The idea is simple:
Pick a whiteboard
Represent an entity as a Post-It (name + some comments)
Draw the relationships on the white board moving the post-its around as required
And when you're done ? Photo of the whole thing for perenity emailed to the persons involved :)
It may seem artisanal but it really remind me of the paper design approach to GUIs.
Have you tried Google Doc's Drawing? The link is one of the diagrams I've done with it.
I like yuml as a very easy way to create diagrams, that also keep that informal look. And no real drawing needed :)
I would use graphviz, but since you say "something that is simple enough as a user", dia is probably a better alternative.
I've used ArgoUML but you'll have to decide whether it's simple enough for what you have in mind.
For the sake of completeness: there's also StarUML, which is (windows) freeware and let's you create uml-diagrams pretty quickly.
Visual Paradigm UML the community edition is free and is good enough for sketching
Open Office Draw works for most of what you want to do too
You specify, that you are not just using U.M.L., most tools, these days are directed to specific U.M.L., you may want to look for a generic drawing tool.
At some projects, sometimes I use Open Office Draw, because, the company doesn't allow me to use another software (the company won't wan't to pay), its similar to Power Point or a reduced, simplified, version of Corel Draw:
http://www.openoffice.org/
In other cases, I have try both commercial and open source apps, but, doesn't like it.
At home, I use (paid software):
http://www.novagraph.com/
along with Open Office Draw.
These one, its also good (paid software):
http://www.smartdraw.com
Good Luck.
If you have an existing codebase you wish for a developer to understand (it sounds like you are trying to help junior devs come up to speed quicker) why not run your code through doxygen
With various output types and the ability to draw class hierarchies it really is a useful tool. The added benefit of something like the html output is that you dont have to cram everything into a finite amount of space since all relationships are hyperlinked. Users can just browse the source - at a type-level - without having to worry much about the details.
I am attempting to use the pipe interface to gnuplot (a standard one gnuplot_i.{cpp,hpp}) in order to generate a real time display of values that are continually changing within another program written in C++. This works ok but I wanted to see if anyone had any suggestions for improvement.
This implementation contains a convenience method to plot a single vector and 2 vectors as a 2D plot. It achieved this by writing out to a temporary file via a standard library call to the mktemp function and then using that as input to a gnuplot plot call. This generated too many temporary files and didn't appear to work well when the update rate on the plot is high (maybe IO limited at a point). I have decided to use the '-' pseudo file in the plot call and just send the vectors directly to the pipe (ended with a single line with "e" on it). This works better but is still not great.
Is there a slicker way to do what I am attempting to do than to continually regenerate the plot when the values have changed? How often is it safe to update the plot with new information? Alternatively, maybe there's a much simpler way to achieve what I am trying to do?
#Andy Ross
I have no "requirements" per se. What I meant by slick was that maybe there was a more elegant approach to doing what I was attempting while still using gnuplot. Although elegant is subjective, I find the approach I am presently taking particularly inelegant. What I meant by safe was whether anyone knew at what update rate there would be IO problems (e.g., latency, lock-up of display, etc.) with said approach.
I'd like to avoid using a toolkit for the following reasons (my short-list at least).
I have found that they are generally nontrivial to install properly on different architectures especially as non-root (and when they require dependencies that aren't standard across OSes).
They incur an additional compilation dependency for other people using this software.
There doesn't appear to be any real standard that most people use for this purpose afiak (myself as well as most people I work with generally just saves off log type files and does post run analysis in MATLAB).
I know/learning gnuplot syntax. I do not know superPlottingApiXX's syntax.
The feature set of gnuplot is almost ideal for the types of things I'd like to be able to do with this software.
However, if you have any particular suggestions in terms of C/C++ plotting libraries that seem like a good fit given the above list I am always interested in suggestions (warning: I have already looked around a good bit to find them).
gnuplot-cpp is an object-oriented C++ wrapper interface around a POSIX pipe connection with Gnuplot.
The example file compiled right away and the interfacing code looks decent; I'll be trying it in my current project.
there is a C2gnuplot library I wrote few years ago. It is very simple but may give you some tips. Basically it uses FIFO files to pass data into Gnuplot.It is able to generate animation from the plots. Here is a video created with the app. I hope this will be useful for you.
Slicker? Safe? Can you be more specific about your requirements?
It sounds like you are trying to do an animated visualization with a tool designed for generating static images. If your display is as simple as you say, why not write a quick GUI app (using the toolkit of your choice) to do the drawing instead?
I am considering the possibility of designing an application that would allow people to develop C++ code graphically. I was amazed when I discovered Scratch (see site and tutorial videos).
I believe most of C++ can be represented graphically, with the exceptions of preprocessor instructions and possibly function pointers.
What C++ features do you think could be (or not be) represented by graphical items?
What would be the pros and cons of such an application ? How much simpler would it be than "plain" C++?
RECAP and MORE:
Pros:
intuitive
simple for small applications
helps avoid typos
Cons:
may become unreadable for large (medium?) - sized applications
manual coding is faster for experienced programmers
C++ is too complicated a language for such an approach
Considering that we -at my work- already have quite a bit of existing C++ code, I am not looking for a completely new way of programming. I am considering an alternate way of programming that is fully compatible with legacy code. Some kind of "viral language" that people would use for new code and, hopefully, would eventually use to replace existing code as well (where it could be useful).
How do you feel towards this viral approach?
When it comes to manual vs graphical programming, I tend to agree with your answers. This is why, ideally, I'll find a way to let the user always choose between typing and graphical programming. A line-by-line parser (+partial interpreter) might be able to convert typed code into graphical design. It is possible. Let's all cross our fingers.
Are there caveats to providing both typing and graphical programming capabilities that I should think about and analyze carefully?
I have already worked on template classes (and more generally type-level C++) and their graphical representation.
See there for an example of graphical representation of template classes. Boxes represent classes or class templates. First top node is the class itself, the next ones (if any) are typedef instructions inside the class. Bottom nodes are template arguments. Edges, of course, connect classes to template arguments for instantiations.
I already have a prototype for working on such type-level diagrams.
If you feel this way of representing template classes is plain wrong, don't hesitate to say so and why!
Much as I like Scratch, it is still much quicker for an experienced programmer to write code using a text editor than it is to drag blocks around, This has been proved time and again with any number of graphical programming environments.
Writing code is the easiest part of a developers day. I don't think we need more help with that. Reading, understanding, maintaining, comparing, annotating, documenting, and validating is where - despite a gargantuan amount of tools and frameworks - we still are lacking.
To dissect your pros:
Intuitive and simple for small applications - replace that with "misleading". It makes it look simple, but it isn't: As long as it is simple, VB.NET is simpler. When it gets complicated, visual design would get in the way.
Help avoid typos - that's what a good style, consistency and last not least intellisense are for. The things you need anyway when things aren't simple anymore.
Wrong level
You are thinking on the wrong level: C++ statements are not reusable, robust components, they are more like a big bag of gears that need to be put together correctly. C++ with it's complexity and exceptions (to rules) isn't even particulary suited.
If you want to make things easy, you need reusable components at a much higher level. Even if you have these, plugging them together is not simple. Despite years of struggle, and many attempts in many environments, this sometimes works and often fails.
Viral - You are correct IMO about that requriement: allow incremental adoption. This is closely related to switching smoothly between source code and visual representation, which in turn probably means you must be able to generate the visual representation from modified source code.
IDE Support - here's where most language-centered approaches go astray. A modern IDE is more than just a text editor and a compiler. What about debugging your graph - with breakpoints, data inspection etc? Will profilers, leak detectors etc. highlight nodes in your graph? Will source control give me a Visual Diff of yesterday's graph vs. today's?
Maybe you are on to something, despite all my "no"s: a better way to visualize code, a way to put different filters on it so that I see just what I need to see.
The early versions of C++ were originally written so that they compiled to C, then the C was compiled as normal.
What it sounds like you are describing is a graphical language that is compiled to C++, which will then be compiled as normal.
So really you are not creating a graphical C++, you are creating a new language that happens to be graphical. Nothing wrong with that, but don't let C++ restrict what you do, because eventually you may want to compile the graphical language straight to machine code, or even to something like CIL, Java ByteCode, or whatever else tickles your fancy.
Other graphical languages you may want to check out are LabVIEW, and more generally the category of visual programming languages.
Good luck in your efforts.
The complexity of a nontrivial program is usually too high to be represented with graphical symbols, which are low in their information content. Unless your approach is markedly different in some way, I am skeptical that this would be of value based on past efforts.
So, practically speaking, his will be useful only for instructional purposes and very simple programs. But that would still be a great target market for a product like this. sometimes people have trouble grasping the fundamentals, and a visual model might be just the thing to help things click.
Interesting idea. I doubt I'd use it though. I tend to prefer coding in a flat text editor, not even an IDE, and for tough problems I prefer a pad of paper. Most of the really experienced programmers I know work this way, Maybe it's because we grew up in a different environment, but I think it's also because of the way we think about programming. As you get more experience, you start seeing the code in your head more clearly than any GUI tool will show it to you.
As for your question, I'd nominate templates as one of the harder / more interesting sort of thing to try to represent well. They are ubiquitous and carry information that you won't have access to as you are designing your tool. Getting that to the user in a useful way should pose an interesting challenge.
What C++ features do you think could be [...] represented by graphical items?
Object Oriented Design. Hence classes, inheritance, polymorphism, mutability, const-ness etc. And, templates.
What would be the pros and cons of such an application?
It may be easier for beginners to start writing programs. For the experienced, it may be get rid of the boring parts of programming.
Think of any other code generator. They create a framework for you to write the more involved portion(s). They also lead to bloated-code (think of any WYSIWYG HTML editor).
The biggest challenge, as I see it, is that any such UI necessarily hinders the user's imagination.
How much simpler would it be than "plain" c++ ?
It can be a real pain, when you wade through truckloads of errors which is typical of code generators.
Further, since a lot of code is generated, you have no idea of what is going on -- debugging becomes difficult.
Also, for the experienced there may be some irritation to find that the generated code is not per their preferred coding style.
I prefer hot-keys instead graphical menus and buttons.
And I think same thing will happen with graphical development tool. Many peoples will prefer manual codding.
But, source code visualizer - should be nice thing.
I like the idea, but I suspect there comes a point where things get far too complicated to be represented graphically.
However, given recent experience at work; it would be useful to give such a graphical interface to a non-techie person to use to create basic drag-and-drop programs, leaving myself free to get on with some "proper" programming ;-) If it can do the job of allowing somebody non-skilled to build something functional it can be a very good thing (even if programming logic escapes them)
There comes a point in such a system where it becomes easier to define what you want to do using literal C++ code, rather than have a user interface getting in the way; it can get frustrating to the sessioned programmer knowing the precise code that needs to be written but then only being limited to the design GUI. I'm specifically thinking about a more common application, such as html editors/designers in which they allow newbies to build their websites without knowing any html at all.
It would be interesting to see how such a system would handle the dynamic allocation of memory, and the different states of a program as time progressed; I suspect that there are some very basic programming concepts that may be difficult to represent graphically.. Polymorphism..? Virtual Classes, LinkList, Stacks/Circular Queues. I wonder for a moment how you would explain an image compression algorithm (such as jpg) successfully too without the help of a gigantic display screen.
I also wonder if such a system would even go to such a low level, and whether you would be dealing with abstracted concepts and the compiler would be working out the best way to do something.
I've been working on a new model-driven software development paradigm named ABSE (http://www.abse.info) that supports end-user programming: It's a template-based system that can be complemented with transformation code. I also have an IDE (named AtomWeaver) implementing ABSE that is in pre-alpha stage right now.
With AtomWeaver, as an expert/architect, you build your knowledge Templates, and then the developers (or end-users if you make your meta-models simpler) can just "assemble" systems by building blocks, and then filling template parameters in form-style editors.
At the end, pressing the "Generate" button will create the final system as specified by the architect/expert.
I'm surprised you think function pointers would be a particular problem. How about anything at all to do with pointers?
A programming language can be represented by a hierarchy of nodes - that's exactly what the compiler turns it into. It is very strange that the UI for editing programs is still a sequence of characters that get parsed, because the degrees of freedom in the editor is way larger than the available set of allowed choices. But intellisense helps to reduce this problem a lot.
C++ would be a strange choice to base such a system on.
I think the major problem of this kind of IDEs are that the code generated becomes unmantainable easily.
This happened to Delphi. It's a really nice tool to develop some kind of applications, however, when we start adding complex relationships between the components, start adding Design Patterns, etc. the code grows to an unmantainable size.
I believe it's also because graphical tools don't apply the concept of MVC (or if they do, it's only in the way that the IDE understands).
It can be really helpful for prototypes and very small applications that don't tend to grow, otherwise it can become a mess for the developer(s)