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== Introduction ==
'''See [[GSoC Ideas]] if you're looking for Google Summer of Code ideas for 2014.'''
 
'''See [[ClosedTasks|Closed Tasks]] for a list of tasks proposed the previous years'''
 
 
<!-- This page contains a list of substantial open tasks from throughout the project. Completing any of them would be of great benefit to the ScummVM project.
 
In theory, all of these tasks should be doable even by somebody relatively new to the project, in particular, as part of a Google [[Summer of Code]] project.
 
It should be noted however that while we suggest that potential GSoC students looks at these tasks they are in no way exclusive to GSoC. Anyone is very welcome to work on any task (or any aspect of it).
 
Besides the tasks collected here, there are of course also the [[TODO]] pages listing more things that need to be done (but with far less details).


This page contains a list of open tasks. Completing any of them would benefit the ScummVM project a lot. At least in theory, all of them should be doable even by somebody relatively new to the project, in particular, as part of the Google [[Summer of Code]]. Besides the tasks listed here, there is of course also the [[TODO]] page listing more things that need to be done (but with far less details).
__TOC__


== Introduction ==
=== Some basic rules ===
=== Some basic rules ===


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The projects below are sketches and ideas. Plus, things evolve over time, so the descriptions might be slightly outdated by the time you read them (although we strive to keep them up-to-date). Hence, you should talk with somebody from the team, probably the person(s) listed as Tech Contact, before starting work on any of them.
The projects below are sketches and ideas. Plus, things evolve over time, so the descriptions might be slightly outdated by the time you read them (although we strive to keep them up-to-date). Hence, you should talk with somebody from the team, probably the person(s) listed as Tech Contact, before starting work on any of them.


All code, unless stated differently, must be written in clean and portable C++, in particular, GCC must be able to compile it (portability exceptions can be made for platform specific code, of course). We also have some [[Code Formatting Conventions]]. Using the standard C++ lib for code used inside ScummVM is at this time not possible. Using it inside non-essential tool should be fine, though.
All code, unless stated differently, must be written in clean and portable C++, in particular, GCC must be able to compile it (portability exceptions can be made for platform specific code, of course). We also have some [[Code Formatting Conventions]]. Using the standard C++ lib for code used inside ScummVM is at this time not possible. Using it inside a non-essential tool should be fine, though.


All of the code submitted must be contributed under the terms of the GPL.
All of the code submitted must be contributed under the terms of the GPL v2+.


We only accept clean and maintainable code. This is a somewhat vague requirement, but as a rule of thumb, if the code does what it is supposed to do, but is not extensible, a quick hack, or we need to rewrite it from scratch to properly integrate it, we will not accept it. In particular, we would rather have a maintainable, clean and incomplete piece of code that we could extend than a complete but unmaintainable piece of code.
We only accept clean and maintainable code. This is a somewhat vague requirement, but as a rule of thumb, if the code does what it is supposed to do, but is not extensible, a quick hack, or we need to rewrite it from scratch to properly integrate it, we will not accept it. In particular, we would rather have a maintainable, clean and incomplete piece of code that we could extend than a complete but unmaintainable piece of code.


=== Some good advice ===
=== Some good advice for [[Summer of Code]] Applications ===
The PostgrSQL folks have some real good
The PostgreSQL folks have some real good
[http://www.postgresql.org/developer/summerofcodeadvice.html Advice to Students on Submitting SoC Applications]. We recommand all students interested in applying with us (or any other SoC project, for that matter) to read this.
[http://www.postgresql.org/developer/summerofcodeadvice.html Advice to Students on Submitting GSoC Applications]. We recommend all students interested in applying with us (or any other GSoC project, for that matter) to read this.


=== Student application template ===
==== Student application template ====
The following was adapted from the FreeBSD [http://www.freebsd.org/projects/summerofcode.html Proposal Guidelines].
The following was adapted from the FreeBSD [http://www.freebsd.org/projects/summerofcode.html Proposal Guidelines].


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* '''Project Title'''
* '''Project Title'''
* '''Possible Mentor''' (optional)
* '''Possible Mentor''' (optional)
* '''Benefits to the ScummVM Community''' - a good project will not just be fun to work on, but also generally useful to others.
* '''Benefits to the ScummVM Community''' - A good project will not just be fun to work on, but also generally useful to others.
* '''Deliverables''' - It is very important to list quantifiable results here e.g.
* '''Deliverables''' - It is very important to list quantifiable results here e.g.
** "Improve X modules in ways Y and Z."
** "Improve X modules in ways Y and Z."
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* '''Project Schedule''' - How long will the project take? When can you begin work?
* '''Project Schedule''' - How long will the project take? When can you begin work?
* '''Availability''' - How many hours per week can you spend working on this? What other obligations do you have this summer?
* '''Availability''' - How many hours per week can you spend working on this? What other obligations do you have this summer?
* '''Skype ID''' - If you don't use Skype, install it.
* '''Phone Number''' - Cellular is preferable, for emergency contacts.
* '''Timezone''' - Where do you live.
* '''Bio''' - Who are you? What makes you the best person to work on this project?
* '''Bio''' - Who are you? What makes you the best person to work on this project?


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=== Anything you can dream of ===
=== Anything you can dream of ===
''Technical Contact'': Our IRC channel, our mailing list, or contact [[User:Sev|Eugene Sandulenko]], [[User:Fingolfin|Max Horn]]
''Technical Contact'': Our IRC channel, our mailing list, or contact [[User:Sev|Eugene Sandulenko]], [[User:DJWillis|John Willis]]


''The Task:''
''The Task:''
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Come up with your personal clever way to improve ScummVM and its various side projects. Be creative. Incorporate the ideas listed below and in our [[TODO]], but don't let yourself be limited by them. Come up with something totally new, or enhance existing features. It's up to you.
Come up with your personal clever way to improve ScummVM and its various side projects. Be creative. Incorporate the ideas listed below and in our [[TODO]], but don't let yourself be limited by them. Come up with something totally new, or enhance existing features. It's up to you.


But of course like with all the other tasks, we recommend that you first talk to us (see above).
But of course like with all the other tasks, we recommend that you first talk to us (see above).-->
 
== Generic infrastructure tasks ==
 
=== Plugins ===
''Technical Contact'': [[User:Fingolfin|Max Horn]]
 
''Background:''
 
ScummVM contains by now over a dozen different engines for different adventure game systems. Each of these engines forms a "plugin", and it is possible to compile these plugins as loadable modules separate from the core of ScummVM itself. This makes it possible to (un)load engine code at will, ideal for systems with tight memory constraints; if you want to play a game, you only need to load the engine for that specific game, and can unload the others.
 
We always compile the engines as "plugins", but by default, they are compiled as so-called "static" plugins; these are not real plugins, but rather the engine gets compiled into the application (i.e. "static linked", hence the name), but is still treated by the rest of the application as a plugin (only that it is not dynamically loaded). Support for true "dynamic" plugin is only available on a subset of all plugins -- essentially most POSIX systems (including Linux, *BSD, Mac OS X) and the Dreamcast.
 
''The Task:''
 
There are various ways in which this plugin code could be improved:
* Add support for real "dynamic" plugins on Windows. This is currently not possible, because the ScummVM plugins rely on "backlinking" from the loaded modules to the core binary. This is not supported on Windows. There are various ways to solve this issue (use Google for more info). This is further complicated by the fact that while the interface of the *plugins* is well-defined (although not quite as well documented -- see base/plugins.h), the converse is not true -- plugins can call virtually arbitrary code within the core of ScummVM.
* Add support for "dynamic" plugins on more systems which might benefit from them.
* Improve the way we search for plugins. Right now we only look in the current directory. Should this be made configurable? On Unix, maybe /usr/share/scummvm should be searched, too? On Mac OS X, the CoreFoundation bundle API should be used to search for plugins inside the ScummVM.app bundle (which would also require the build system to be enhanced to properly bundle all plugins). Etc.
 
=== GUI ===
''Technical Contact'': [[User:Sev|Eugene Sandulenko]], [[User:LordHoto|Johannes Schickel]]
 
''Background:''
 
ScummVM implements its own GUI code. We can't use any of the portable GUI kits out there, as they are mostly not portable enough, use too many resources, or simply are not flexible enough to work atop our backend system. Also, our GUI must look equally good with 8bit, 16bit or 32bit graphics, at 320x200, 320x240 or 640x480 resolutions -- and ideally also at 240x200 or at 1280x1024.
 
Currently we have a quite flexible system for defining the look and feel of our GUI. Almost every aspect of it can be specified via external theme file described [[GUI_Themes/Specs|here]].
 
''The Task:''
 
There are many things missing:
 
* Shadows are not configurable
* Not all widget aspects such as font to use are configurable
* We need to implement possibility for backends to extend GUI by adding their own tab in options dialog
* It would be nice to have antialiased fonts (possibly optionally -- we still need to support relatively low end devices, after all)
* Perhaps implement portable support for TrueType fonts
* We need better About dialog
* We need dialog for save game selection
* There are [[GUI_Themes/TODO|a number]] of small things to do which will make GUI behavior more predictive
* Modern Theme renderer should be reworked to make it faster, for example currently shadow drawing is rather slow (and hacked)
 
=== New Rendering Pipeline ===
''Technical Contact'': [[User:Fingolfin|Max Horn]], [[User:Sev|Eugene Sandulenko]]
 
''Background:''
SDL backends is used by most of our backends. The current rendering pipeline in the SDL backend is rather convoluted and complex. It could certainly benefit from a thorough overhaul. But this is not an easy task, given the number of extra features one has to support: 8->16bit conversion, scaling, aspect ratio correction (in place), separate mouse cursor scaling, separate mouse palette, screen shaking, and of course the (GUI) overlay.
 
''The Task:''
Take SDL backend, remove all current dirty rectangles code and implement proper dirty areas detection. That is, it keeps a copy of the last rendered frame, then when updateScreen() is called compares the current against the previous frame, and from this automatically computes which pixels have to be updated. Then we could run some performance comparisons; in particular it would be interesting to learn how this affects CPU and RAM usage (of course we'd need an extra buffer for the prev frame, but maybe we can save in other places).
 
There are various details to consider for this, of course: Scalers usually look at multiple input pixels to compute their output, so whenever the autodirty code sees a changed pixel, it may also have to dirty neighboring pixels. One way to do that w/o having to look at all input pixels multiple times would be to compute a "dirty bitmap", where for each pixel we keep a single "dirty" bit. Yes, more memory again -- it's a speed vs. memory tradeoff, and I am not sure which resource is more important in this case (and this might vary from architecture to architecture), so some experiments might be necessary.
 
Also, one has to decide what is better: Keeping the prev frame before or after the 8->16bit conversion. The former takes up less space and potentially allows us to avoid converting certain pixels from 8 to 16 bit; OTOH, the latter approach gives us perfect "palette change handling" for free (for example right now in games which do color rotation, we always invalidate the whole screen in the SDL backend, even if perhaps only a few pixels changed at all).
 
But automatic dirty updates might not be ideal for all backends, so keeping an (optional) dirty rect API might still be a good idea (right now we have this implicitly via copyRectToScreen/ copyRectToOverlay; in the future this *might* be phased out (nothing has been decided yet, though), but then we could still keep a markRectAsDirty() method (which on backends doing auto-dirtying would simply do nothing).
 
== Audio related tasks ==
 
=== Add support for TFMX, and more Amiga MOD formats ===
''Technical Contact'': [[User:Sev|Eugene Sandulenko]], [[User:DrMcCoy|Sven Hesse]]
 
''Background:''
 
Since we're adding (and have added so far) support for different Amiga game versions, we need support for the sound files too.
Currently we need support for following formats:
 
* TFMX a (non-MOD) format used by Monkey Island 1. There is a [http://freshmeat.net/projects/tfmx-play/ player] for it already, which is written in rather poor C, also it misses several macros implementation. [http://www.wotsit.org/download.asp?f=tfmx This] documentation may be useful, it isn't complete though. If you don't have the Amiga version of Monkey Island 1 you can use the [http://quick.mixnmojo.com/demos/mi1amigademo.zip demo] of Monkey Island 1. The main objective of this task is to write a TFMX player with all the effects and macros needed by the Monkey Island music tunes. Work can be based on the original - uncommented - replayer routine disassembly (Motorola 68k).
 
* MaxTrax support for Kyrandia 1. The Amiga version isn't supported yet, but [[User:LordHoto|LordHoto]] will be working on it when his copy arrives. A Motorola 68000 (short: 68k) assembler implementation by Joe Pearce can be found [http://amiga.emucamp.com/wt/files/sources/SRC_MaxTrax.lzx here]. It would be necessary to re-implement it in proper C++, naturally a must for this task is 68k assembler knowledge. If you don't have the Amiga version of the Legend of Kyrandia, there are [http://www.exotica.org.uk/tunes/unexotica/games/Legend_of_Kyrandia.html sample modules] available.
 
* SoundFX is used by the Future Wars and Operation Stealth games of the cinE engine. The player is already implemented, but it cannot load music stored in Amiga format with combined track info and instrument info. The existing code only supports loading them separately, which happens to be the way they are stored in the DOS version. If you don't have the Amiga versions of the required games, you can use the [http://quick.mixnmojo.com/demos/fw_demo_ami.zip demo] of Future Wars and the [http://quick.mixnmojo.com/demos/op_demo_ami.zip demo] of Operation Stealth. A standalone player has been written in the past, initially for the cinE project (the source is available [http://membres.lycos.fr/cyxdown/scummvm/cinematique/ here]) which should be able to play the music tunes of Future Wars, Operation Stealth, Cruise for a Corpse and Another World.
 
=== MIDI enhancements ===
Many of the adventures supported by ScummVM make use of MIDI music. Which is why we already include several device drivers for various MIDI APIs and emulators (e.g. ALSA, Windows MIDI, Mac OS X CoreAudio/CoreMIDI, fluidsynth...).
 
==== MIDI device configuration ====
''Technical Contact'': [[User:Fingolfin|Max Horn]]
 
''Background:''
 
Right now, the MIDI drivers are treated by ScummVM in a rather single minded fashion: Either a driver is linked in and hence "available", or not. It's not possible to configure anything about them (like ports to be used etc.), nor does it ever take into account that a single driver might correspond to multiple devices (after all, you can plug several sequencers into your MIDI port; or you could have configured several different sound font settings in your MIDI emulator).
 
''The Task:''
 
* Add an API for querying the OSystem backend for a list of available MIDI devices (not drivers)
* Information about the selected device must be serializable, so that it can be stored in the config file
* Selection of devices via command line should be possible
* It must deal with devices being added/removed (at least between runs of ScummVM, ideally also while ScummVM is running)
* Devices should be configurable via the GUI; this needs to be done in a flexible (different devices/drivers offer different settings) and portable fashion.
 
==== XMIDI parser ====
''Technical Contact'': [[User:Fingolfin|Max Horn]]
 
''Background:''
 
Several of our games make use of the XMIDI format. We already have a parser for it (see sound/midiparser_xmidi.cpp), which was based on code from the [http://exult.sf.net Exult] project, but it is incomplete.
 
''The Task:''
 
Specifically, we require support for XMIDI_CONTROLLER_FOR_LOOP and XMIDI_CONTROLLER_NEXT_BREAK. The XMIDI code from the [http://exult.sf.net Exult] project (see Exult's audio/midi_drivers/XMidiSequence.cpp) could be used as a reference again. Another good reference for this task is the AIL library which has been recently open-sourced by its [http://www.thegleam.com/ke5fx/ author].
 
== Tools ==
 
=== Tools: Overhaul the compression tools ===
''Technical Contact'': [[User:Fingolfin|Max Horn]]
 
''Background:''
 
We offer a multitude of command line tools in a separate package (scummvm-tools).
The majority of these tools are used to (re)compress audio data. This greatly helps users who want to play their games on devices with limited storage, like PDAs and smart phones.
 
The user can choose between MP3, Ogg Vorbis and (in those cases where it makes sense) FLAC compression. The tools take the original data files, extract sound data, compress them, and reassemble everything into new (smaller) data files.
 
''The Task:''
 
There are various ways in which these tools could be improved:
* Write a portable GUI for them -- that's a big task and hence has its own section (see below)
* Unify their command line interfaces
* Unify the actual compression code -- some partial work on this exists, but with a crude ad-hoc API, which makes it very difficult to use them and also inefficient
* Right now, compression works by invoking external encoder binaries (oggenc, lame, flac). To this end we write data into a temporary file, invoke the external encoder, and read back the file it created. It would be nice if one could instead link against suitable encoder libraries, and provide compression binaries which are fully self-contained. Also this would make it possible to perform in-memory compression (which could provide a noticeable speedup).
 
== Engine/game specific ==
 
=== Residual: Light-weight software renderer ===
''Technical Contact'': [[User:Aquadran|Pawel Kolodziejski]]
 
''Background:''
 
Residual currently offers two different renderers: OpenGL and TinyGL. Neither offers an ideal solution. Not all OpenGL drivers accelerate the operations needed by Grim Fandango, and the TinyGL renderer, apart from being somewhat glitchy, doesn't run well on low-end hardware.
 
''The Task:''
 
It would be nice to have a more light-weight cross-platform renderer. Since Grim Fandango uses mostly static backgrounds, we could probably gain a lot just from more intelligent screen redrawing.
 
This shouldn't require any deeper knowledge of the game engine. The renderer appears to be fairly well separated from the rest of the engine already.
 
=== Objectify CinE engine ===
''Technical Contact'': [[User:Sev|Eugene Sandulenko]], [[User:Aquadran|Pawel Kolodziejski]]
 
''Background:''
 
The cinE engine started out as an external project started by [[User:Yazoo|Yaz0r]]. Originally it was written in plain C.
ScummVM is a C++ project, so we need to objectify this engine without changing/breaking its behavior.
 
The engine itself is well-structured, hence many functions / variables which might be good candidates for being grouped together into a C++ class are already grouped by files.
 
No deep knowledge of the engine internals is required, but in any case the Engine is not that big, and thus
it should be possible to learn enough about it to start working in a relatively short amount of time.
 
We have previously "objectified" several other engines, namely SAGA, Gob and AGI, so one can learn a lot about various approaches how to do this by tracing through our SVN repository.
 
=== Add 16bit graphics support to SCUMM engine ===
''Technical Contact'': [[User:Kirben|Travis Howell]], [[User:Sev|Eugene Sandulenko]]
 
''Background:''
 
The SCUMM engine was originally developed for palette-based graphics. At version 6 it was forked by Humongous Entertainment, which extended it significantly. Their later games started to use 16bit graphics for backgrounds and actors. See [[Humongous Entertainment/Progress/16bits Support|here]] for more detailed information.


This task requires good knowledge of C++, as we need a solution which will not clobber our code,
== Current Open Tasks ==
will have minimal impact on 8bit games, and can be optionally turned off at compilation stage.


If you don't have any of the required games, there are several [http://www.scummvm.org/demos.php demos] available. A 16bit graphics demo example would be the [http://quick.mixnmojo.com/demos/ffcovedemo.zip Freddi5 demo].
Below is a table of some open tasks that people may wish to consider working on and links for more information.
These tasks can be considered in addition or in conjunction with anything on our [[TODO]], any other task or your own 'Anything you can dream of' project.


=== Add event recording ===
They are usually NOT kept up to date. Please contact us (ideally via IRC) before you even start thinking about one of these tasks. Again, see [[GSoC Ideas]] if you're looking for Google Summer of Code ideas for 2014.
''Technical Contact'': [[User:Sev|Eugene Sandulenko]], [[User:Fingolfin|Max Horn]]


''Background:''
<!--The GSoC workload figure was used to indicate the percentage of GSoC project time we consider this task will take an average competent programmer. These are just rough guides and should you feel you can undertake a task well in less time (or take longer but deliver a much better or more feature rich result) please feel free to mention this on your application and select your tasks accordingly.-->
All engines in ScummVM are driven by three sources of external influences (input):


* Mouse events
* Keyboard events
* Pseudo-random number generators (several, in different parts of the code)


It would be useful to have some layer in between our system-dependent backends and engines which can record these events to a file and play them back later. Time control is crucial here, since the games take some time to react to these events (i.e. you need to record when the events occured, too).
<dpl>
category = Open Tasks
include = {Infobox_OpenTasks} Inforow
table = class="wikitable sortable" ,-, Task, (Outdated) Workload, Technical Contact(s), Subsystem
</dpl>


This will significantly help with regression testing, as it would be possible to make records of certain scenes that caused bugs; we can record the incorrect behavior, and then automatically run these tests to compare the recorded with the expected behavior. (How this comparision would be done precisely also needs to be determined. You could for example compare screen content).
== Current TODO Lists ==


The solution should be high-level, perhaps in the form of a custom event loop, so that all engines will be able to use it with minimal effort. (Note that the PRNGs likely are the biggest obstacle here).
Below is a table of all the TODO lists currently on the wiki. These less detailed tasks can be considered in conjunction with anything from our larger open task list or your own 'Anything you can dream of' project.


== Implement "return to launcher" feature ==
A TODO list by its very nature if often made up of vague pointers or ''one line'' ideas. Please seek clarification if you are unsure of any [[TODO]].
''Technical Contact'': [[User:Fingolfin|Max Horn]]
 
''Background:''
 
Presently we have to exit the ScummVM application completely when users exit a game because most
engines do not clean up memory properly on their exit.
 
''The Task:''


What we need is to analyze what's going on there and plug all memory leaks, properly shut down
subsystems like sound, so it will be possible to play more than a single game within one
session.


The task will require good use of a memory leak analyzer and C++.
<dpl>
category = TODO List
include = {Infobox_TODO} Inforow
table = class="wikitable sortable" ,-, Task, Technical Contact(s), Subsystem
</dpl>
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