SoC2012 Nephro

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See the list of Summer of Code 2012 Ideas

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Description

Dmitry Kovalenko(Nephro) - Further Lua

Simplify LuaAI
Right now, the LuaAI system is in a state, where it can be used for artificial intelligence system development for Battle for Wesnoth campaigns, but it's usage is quite complicated and requires effort to get the system off the ground and make it run. To simply to launch a campaign with an empty LuaAI(by empty, I mean, not doing anything) a UMC developer is required to write a couple dozens of lines of code(not even mentioning the bugs that he will encounter on the way). While it seems, that we could simply hide the boilerplate code in a template or behind a macro, the situation is a bit more sophisticated(Later I will describe that in more detail). Instead of running away from this problem, I will work towards an elegant solution, creating an effective back-end system, and a clean user development environment.

The project

Intro

As I already stated in the short description, the LuaAI system is not very easy to use, at this stage. We can say the same about the C++ part of the AI, if a person wants a new candidate action, for example, he will have to dig in the C++ code, understand, how it works, code in C++, compile, debug. That is the way of C++, but shouldn't be the way of LuaAI.
LuaAI was designed to simplify AI development, to provide a way of trying out their ideas for non-programmers. If we design a usable and simple LuaAI environment, even the further development of the current mainline AI would be simplified. Stages and candidate actions could just be written and tried out in Lua, and if a developer is satisfied with its work, he can either leave the AI element in the Lua form and add it to the main RCA loop, or translate it to C++ and compile once. The translation must be trivial, considering that LuaAI was properly prepared. LuaAI should provide all the power that C++ has.

Known problems

• LuaAI lacks a lot of tools C++ has(e.g. the attacks and enemy_attacks vectors)
• Some heavyweight objects are currently being inefficiently handled by the LuaAI(e.g. the translation of move maps and any container type objects, that are getting passed to LuaAI)
• Users of LuaAI have discovered bugs in the current implementation(some of them already fixed by me, some fixes are planned)
• Boilerplate code in the scenarios(discussed lower in the "Boilerplate code" section)
• Lack of error handling and debugging tools(e.g. if you make an error in your LuaAI engine code, the game will just crash)
• Lack of documentation(the lack of documentation will partially resolve, once LuaAI will be cleaned from the boilerplate code, there will simply be less things to document)

Goals

• The main goal of the project is to make the LuaAI a fully functional, safe, stable and most importantly simple to use AI development environment. I don't even need to mention, that it shouldn't have any bugs at all, the known ones must be fixed as soon as possible, the unknown ones must be discovered.
• The secondary goal, but not less important, is to provide some kind of a debugging interface, for the LuaAI devs. I am not quite sure, how much time will I have for this, but certain in-game GUI overlays, displaying the workflow and results of the LuaAI engine code, ca's and stages are, most certainly, top priority.

Documentation

As far as I know, documentation of code is not part of the GSoC program, but I decided, that I will spend at least one hour every day in the evenings, to create documentation for the whole AI system(except if I run short on time again, then I am going to focus on my project more). From my experience last year, I know, how much a UML diagram would've helped, when dealing with the composite AI system, that combines several design patterns and is not easy to comprehend at first, due to its size. Of course, each peace of code produced by myself, will also be documented properly, no matter what. I also got pointed out, that I left some of my previous code undocumented, so that will be handled asap too.

IRC

Nephro, neph

SoC Application

Submitted to google

Questionnaire

Off topic: I did this questionnaire last year, but I don't remember what I wrote in it. I won't look on purpose, until I complete this one, and try to see, whether I've changed at all...

1) Basics

1.1) Write a small introduction to yourself.
Hi, my name is Dmitry Kovalenko and I am aspiring software developer. I've been interested in sciences and engineering since about 5th grade, about that time, I got my first PC without and, without any internet, started to hack around it. It was old and semi-broken, but I got it to run Windows 95 and was very proud of myself. I played a lot of games on it, despite the fact that my games were 10 years older than the games of my classmates, and one day, I decided to write my own game, which would combine the brilliance of my favorite games, lacking their flaws. I failed, of course, at the very first steps, but those were also the first steps towards the career I am pursuing now, 5 years later.

1.2) State your preferred email address.
nephro dot wes at gmail dot com

1.3) If you have chosen a nick for IRC and Wesnoth forums, what is it?
Nephro on irc.freenode.com and Nephro in the forums

1.4) Why do you want to participate in summer of code?
Last year, it was all about proving to myself that I can get accepted and make it through. This year it's exactly the same, only to add the word "again" to the previous sentence. To be honest, I was very disappointed in my performance last year. I was slow, inefficient, imprecise(left a fair amount of bugs after myself) and a bit unorganized. This year I want it to be good, like it should be.
I can't even compare the experience gained working on this project with a mentor to anything else. The large sophisticated codebase, working with other people directly, designing for long term, milestones(which I like to consider deadlines), it all allows to immerse in gamedev, while not applying too much pressure, like corporate development.

1.5) What are you studying, subject, level and school?
Computing Science, year 2
University of Glasgow, Glasgow, Scotland, UK

1.6) What country are you from, at what time are you most likely to be able to join IRC?
Right now I reside in Scotland, but will, most probably, live in Latvia during the summer. I am usually online during the working day time in Europe and most of the evenings.

1.7) Do you have other commitments for the summer period ? Do you plan to take any vacations ? If yes, when.
I have no commitments during this summer, except for maybe rare sports matches, but they usually take place on the weekends, so will not affect my workflow.

2) Experience

2.1) What programs/software have you worked on before?
I participated in lots of programming contests before going to University. Therefore, I have experiences in writing "one algorithm programs"(contest program that solves a particular mathematical or algorithmic problem), high speed development(in contests, where we had to write up an app in a matter of hours) and some tricky stuff(for contests that tested skills in creating systems from several unrelated parts, not only programming). I've also spent two summers working in a small company, once expanding the functionality of a social network and once developing a server side for a browser based game.
2.2) Have you developed software in a team environment before? (As opposed to hacking on something on your own)
I have been working in a team environment for two summers, in the company I told in (2.1). Also, several contests were also team-based, I was working with very gifted people and together we managed to win a couple of trophies. I also consider my last summer project for GSoC with Wesnoth a teamwork experience, since I wasn't developing quite what I wanted, but rather, what we discussed to presumably be good beforehand.
2.3) Have you participated to the Google Summer of Code before? As a mentor or a student? In what project? Were you successful? If not, why?
I have participated in GSoC 2011 for Wesnoth as a student. The project was about expanding the functionality of LuaAI and improving the AI system in general. Although I've seemed to have passed all the milestones for Google and was successful in a program, I am not quite happy about myself. I had a good idea that the organizers liked too, but before I could tackle the implementation of it, I needed to complete a compulsory part. It took me much longer than it should have, I kept constantly stumbling on weird errors, bugs, sometimes I implemented the wrong designs and had to redo. In the end, I didn't even touch my own idea, because the summer ended faster than I expected.
I think the big mistake there, was overestimating my own abilities. I also didn't evaluate the amount of compulsory work correctly, thinking it's mostly straightforward and I won't encounter any problems along the way.
2.4) Are you already involved with any open source development projects? If yes, please describe the project and the scope of your involvement.
I am currently a developer for Battle for Wesnoth. I tried to engage in other OSS projects, but University workload didn't give me a chance to do that.
2.5) Gaming experience - Are you a gamer?
Wouldn't call myself a gamer, I don't like that word. But I really like playing qualitative games, but recently I had no time to play a lot myself, so I became more of a spectator, watching professional players play on the global competitive scene.
2.5.1) What type of gamer are you?
I started out like most of us, playing classic games on an old pc. When I first got a good and powerful PC, I met people, who involved me in our regional competitive scene. From that point I played less and less single player and moved to competitive multiplayer. At this point, I don't play single player games at all, they just don't give me the challenge, that I need, anymore.
2.5.2) What type of games?
I am a big fan of the MOBA(Multiplayer online battle arena) genre, it is getting very popular in the world, even starting to push the grands like Counter-Strike and Starcraft aside. I also enjoy watching a good match of Starcraft 2 once in a while and really respect the talented players of that game.
2.5.3) What type of opponents do you prefer?
Lately, the criteria for both, teammates and opponents, are skill level, mental capabilities and age. It's not that I don't like young people, they just more often don't care about the game. On a typical day, I would usually not care about games too, but if I find time to sit down and play, I want to gain maximum experience during that time and I need the people playing with and against me taking it all seriously.
2.5.4) Are you more interested in story or gameplay?
When I play a game, I always analyze the interesting parts of it. A great game must find the perfect balance between both, but my mind is usually oriented on the engineering aspects, such as game dynamics, gameplay mechanics and the flexibility of the game engine. This gives me a way of comparing different games and finding the most enjoyable one.
2.5.5) Have you played Wesnoth? If so, tell us roughly for how long and whether you lean towards single player or multiplayer.
I have played wesnoth during school years. I lived 50 km from my school and traveled 2 hours by train everyday. It wasn't so tough, because I had my laptop and some good games on it, one of which was Wesnoth. We played it both, SP and MP on the same machine. I also played a lot of wesnoth last year, when I lived in a flat with no internet, that was probably the time when I have completed most of the scenarios.
2.6) If you have contributed any patches to Wesnoth, please list them below. You can also list patches that have been submitted but not committed yet and patches that have not been specifically written for GSoC. If you have gained commit access to our SVN (during the evaluation period or earlier) please state so.
I am developer of Wesnoth and have quite a few commits listed on my name. The latest ones are only small bugfixes. Right now I am working on a bigger and more interesting, so I'll probably link to it when it's done.

3) Communication skills

3.1) Though most of our developers are not native English speakers, English is the project's working language. Describe your fluency level in written English.
I study in the UK, so English isn't a problem for me. I received a band of 7.5 in the IELTS test, which is considered very good.
3.2) What spoken languages are you fluent in?
I am a native Russian speaker, but was born in Latvia. These are the two languages besides English, that I use almost on a daily basis(not too much Latvians here in Scotland, but there are a couple).

3.3) Are you good at interacting with other players? Our developer community is friendly, but the player community can be a bit rough.
I had absolutely no interaction with the player community last year, and I doubt that I will encounter such a need this year, due to the specifics of my project, but I can assure you, that I am used to dealing with all kinds of behavior, and am pretty good at settling things down, if the situation becomes less friendly than it is needed.

3.4) Do you give constructive advice?
Can't judge myself, but I try to always back my words up by constructive arguments.
3.5) Do you receive advice well?
Yes, as long as the person, who gives the advice, clearly explains the reasoning. If I hear phrases like "Just do it that way, because it's the right way", I won't immediately ignore that, but will try to find reasoning elsewhere, if the author isn't too constructive about it.
3.6) Are you good at sorting useful criticisms from useless ones?
I think I am. I developed these skills thanks to one of my hobbies: music production. I like to have a go in my digital audio workstation once in a while, just for fun, and I sometimes post things on forums. I usually hear a lot there, but only 10% usually makes sense to me. I've never actually encountered inappropriate criticisms while working on wesnoth. People always have a point, when they ping me out in IRC and ask to fix something I screwed up.
3.7) How autonomous are you when developing ? Would you rather discuss intensively changes and not start coding until you know what you want to do or would you rather code a proof of concept to "see how it turn out", taking the risk of having it thrown away if it doesn't match what the project want
I used the "see how it turns out" method when I was younger, it got clear to me pretty fast, that I won't get far this way. In the pre-GSoC period last year, I didn't discuss my changes to the code enough, and ended up redoing a very big block of code almost from scratch. Since then I've explored the current design more deeply, and my ideas now seem to be closer to the ideas of the senior devs, but I usually still ask questions about the design, before starting, to save the time of myself and the person I am asking.

4) Project

4.1) Did you select a project from our list? If that is the case, what project did you select? What do you want to especially concentrate on?
I chose the "AI: Make lua AI development and usage easier". The choice is described in more detail in the Project section of this wiki page.
4.2) If you have invented your own project, please describe the project and the scope.
-
4.3) Why did you choose this project?
The choice is described in more detail in the Project section of this wiki page.
4.4) Include an estimated timeline for your work on the project. Don't forget to mention special things like "I booked holidays between A and B" and "I got an exam at ABC and won't be doing much then".
The timeline will be provided in the Timeline section of this wiki page. 4.5) Include as much technical detail about your implementation as you can
The project is described in more detail in the Project section of this wiki page.
4.6) What do you expect to gain from this project?
Experience, implementation skills and most importantly - confidence.
4.7) What would make you stay in the Wesnoth community after the conclusion of SOC?
Wesnoth community is great as it is. I don't see a single change needed to be done. I became inactive for almost a year, only due to the University workload, which caught me off guard this year.
The people are all friendly, helpful and very competent. While I was here, I got help on so many things besides the game itself: design patterns, C++ help, Lua help, overall game development process and so much more. This community is a very great place, where people can learn in a fun way, not investing a penny.

5) Practical considerations

5.1) Are you familiar with any of the following tools or languages?

• Subversion (used for all commits)
• C++ (language used for all the normal source code)
• STL, Boost, Sdl (C++ libraries used by Wesnoth)

I have been using the three technologies listed above quite extensively for Wesnoth development during last summer.

• Python (optional, mainly used for tools)

Python is the language used in our University during first year computing courses, so I am quite agile with it.

• build environments (eg cmake/scons)

I use cmake for my wesnoth builds and try not to forget add new files to other build system config files.

• WML (the wesnoth specific scenario language)
• Lua (used in combination with WML to create scenarios)

Used both WML and Lua during my project last summer.
5.2) Which tools do you normally use for development? Why do you use them?
While working on Wesnoth, I usually use KDevelop and Subversion(cli). KDevelop provides me with a neat and comfortable development environment, it has decent autocompletion, code checking and never causes problems for me. Also, wesnoth has a project file for this IDE, so I don't have to worry about more technical, not related to my actual tasks, things.
Subversion is, of course, the version control system that wesnoth generally uses, it also suits my needs, and I am not even considering switching to something else at the moment.
For university work, we are forced to use Eclipse for most of the development, some other custom IDEs for processor/chip programming and IDLE for Python scripts.

5.3) What programming languages are you fluent in?
Languages relevant to BfW: C/C++/Lua, + basic WML I might require during testing, documentation and demonstration of features I'm working on.
Experiences irrelevant to the project:

PHP/MySql - moderate level, used it once for professional development
Java/Python - Languages I use for university and take courses in
C#/Monodevelop - used once for professional development and a couple of times for contest programming
Pascal - used quite a lot for contest programming and algorithm studies, when I was younger.

5.4) Would you mind talking with your mentor on telephone / internet phone? We would like to have a backup way for communications for the case that somehow emails and IRC do fail. If you are willing to do so, please do list a phone number (including international code) so that we are able to contact you. You should probably *only* add this number in the application for you submit to google since the info in the wiki is available in public. We will *not* make any use of your number unless some case of "there is no way to contact you" does arise!

No problems with talking on the phone. I will provide my telephone number and my skype ID later.