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PlanetPlanet

Welcome to the ScummVM planet - This aggregates the personal blogs of developers, teams members and active participants from all around the ScummVM community.
If you wish to subscribe to updates to the planet or individual blogs please use the links on the right hand side.
To add your blog to the planet contact DJWillis.

February 01, 2016

ScummVM News Headlines

ScummVM Release 1.8.0 Testing is Starting

After a very long break, we are finally starting preparations for our next release, ScummVM 1.8.0.

The last one year and a half have been very busy, and we added 10 (ten, zehn, dieci, dix, diez, десять) new games:

  • Rex Nebular and the Cosmic Gender Bender
  • Sfinx
  • Zork Nemesis: The Forbidden Lands
  • Zork: Grand Inquisitor
  • The Lost Files of Sherlock Holmes: The Case of the Serrated Scalpel
  • The Lost Files of Sherlock Holmes: The Case of the Rose Tattoo
  • Beavis and Butthead in Virtual Stupidity
  • Amazon: Guardians of Eden
  • Broken Sword 2.5: The Return of the Templars
  • Labyrinth of Time

Also, we had a major rewrite of the AGI engine, so all AGI games should work better, but could also have new, unexpected bugs.

Thus, we need your help with testing out these games, including AGI-based ones. For your convenience, we gathered together what requires testing on our wiki. There are also a few other old classics on that list that could use another run through.

You need to grab a daily build of ScummVM and you may start helping right away! If you happen to find any bugs, please report them on our bug tracker. After completing one of the games, please let us know on the forums so we can mark your progress on the wiki and other players can concentrate on untested games. Please be sure to follow our guidelines for release testing, which can be found here.

Also some of these games require screenshots, which you can make along your gameplay.

Happy adventuring (in a test mode)!

by sev (nospam@scummvm.org) at February 01, 2016 09:00 AM

January 27, 2016

James Woodcock

Revolution’s 25th Anniversary Box Set – My Enhanced Music Featured

My Beneath A Steel Sky enhanced music features in Revolution's 25th Anniversary Box Set.

by James Woodcock at January 27, 2016 08:52 PM

January 23, 2016

ScummVM News Headlines

The labyrinth must be destroyed!

While aboard the subway, your train car is sucked into an alternate dimension, a labyrinth that spans the space-time continuum. Its creator, Daedalus, is forced to oversee its construction by the evil King Minos, who wants to use it to invade and conquer all times and places. Daedalus pleads for the player to find a way to destroy the labyrinth before Minos can complete his conquest.

The ScummVM Team is proud to announce that Labyrinth of Time is now playable in ScummVM using the latest daily builds, and is ready for testing.

Please report any bugs as well as unknown versions you find in our bug tracker, following our bug submission guidelines. Any screenshots of your playthrough are as usual welcome.

Many thanks to The Wyrmkeep Entertainment Co. for sharing the game's original source code with us!

by md5 (nospam@scummvm.org) at January 23, 2016 09:00 AM

January 19, 2016

ScummVM News Headlines

New home for our main website

We have been using SourceForge.net for many years. It was the very first home for our project, and it served us very well. However, we had to move on, and we were looking for a new home. Last year Florian Schicker, CEO of easyname GmbH approached us with the thrilling proposal to donate a server and host it in their Data Centre. And what makes it so special is that they are doing it "because they are veeeery big fans of the good old scumm games"! Go, look at company teampage in that fancy scumm-feeling! A really generous proposal and completely unexpected.

Thus, we are moving. First we moved our main website and downloads, and you probably already noticed the speed boost thanks to the new service. Also, we said goodbye to the advertisements during downloads, as they were provided by SourceForge.net. The only ads that will be associated with this project from now on are the ones we want to do by ourselves (and that, of course, includes easyname.com, look at their nice logo in the right pane). Eventually, we will move more services to the new server, and perhaps even extend it with something new.

So please join us in our joy of a new home!

by sev (nospam@scummvm.org) at January 19, 2016 09:00 AM

December 16, 2015

Stefano Musumeci (subr3v) - GSoC

Technical Art - VIII

With my script being finished all I needed to do was model skinning: after watching the live demonstration  the lecture and the labs I started skinning my model by using the Smooth Binding first and then refining weights with the Weight Painting Tool.
At first I was confused and I couldn't exactly wrap my head around the concept of skin weights as sometimes painting something over some vertices would undo previous work which I had done, but thanks to the separated meshes and after watching some tutorials (especially this tutorial from Jason Baskin) I started having some nice results.

The end result was quite satisfying, even though some bits of my mesh are not deforming properly (especially around shoulders) I think the overall model looks quite smooth which is what I wanted to achieve by the end of the process.

The problem with the shoulders was probably brought up by the way the model topology was laid out, I think that having a different starting pose would have made easier but by the time I realised that it was too late and there was nothing I could have done, the process of skinning was actually very interesting because it ties up all the "invisible" work done through the rig in a very tangible way.

Now that I have been through the full process of rigging and skinning a model I feel more confident in my ability to judge model topology and predict how the model would deform.

I believe this is a never ending process that is usually refined over time and the only thing that can guide towards the decision of the topology of a model is the experience gained in previous attempts to rig and skin other models.

by Subr3v (noreply@blogger.com) at December 16, 2015 10:44 PM

Technical Art - VII

Since I finished working on the model rig I decided to focus more on the scripting side of the module before going back to skinning, as I mentioned few posts ago I am planning to develop an auto model picker tool.

The basic features that I want this tool to have are:
  • Automatic rendering of whatever the user is looking at the moment, so that the user can decide to create pickers for specific parts of the model
  • Possibility to have multiple picker views and being able to swap between them
  • The picker should automatically detect and create a button for each joint and control shape in the scene (discarding those which are not visible in the current view)
  • The user should be able to filter out joints based on name patterns or type

With this in mind, I want to design the tool's code so that it could be expanded in the future to add additional features such as loading/saving picker views and further customization like automatic UI controls to tweak set driven keys and special attributes.

Once I planned the features I started working on the actual UI implementation and this was the final result:


Getting a screenshot from the user view proved to be rather easy: I just needed to use the playblast command and save to a file the results and then subsequently use that image inside the form, transforming each joint from world space to screen space was not as simple but after researching ways to find the view and projection matrices for the current camera I managed to find the screen space position of any object in the scene quite easily.
Once those two matrices are available the screen space position can be easily computed by transforming the world position of an object through the view and projection matrix.

Since one of the long term goals was to have a save and load feature I needed a way to store those two pieces of data within my script, so I made a PickerData class that contains all the information required to transform any object in screen space for that specific user configuration.

The PickerData also contains all the information about spawned buttons and their corresponding object: this is used within the filter function to allow the user to filter out specific joints or control shapes in the scene should that be necessary.


Here's an example of the final script working with my rig:

by Subr3v (noreply@blogger.com) at December 16, 2015 10:16 PM

Technical Art - VI

After lots of hours of hard work I finally managed to finish the rig! The most difficult thing I had to think about was creating two separate chains of hierarchy: one for the offset groups and control shapes and one for the actual joints; since those two are blended together as everything has to be controlled by the master controller I struggled in my first steps and managed to break the skeleton hierarchy more than once by wrongly parenting control shapes directly to joints rather than using constraint to control them.
But once I finally understood the whole concept of parenting I feel more confident in building basic human rigs and venturing forward to more complex ones.
The missing piece which I wasn't quite grasping was the concept of constraints, so I did research more tutorials and documentation about them and I found some interesting types of constraints which are not strictly related to rigging but could definitely help during animation: one of the was the normal constraint which enables the user to orient a node to the normal of a surface; this would make animating an object sliding through a curved surface quite easy, which made me realize how powerful some of these tools can be if used properly!

For reference here's a screenshot of my final rig:

Screenshot of completed level


I might still decide to add some small things along the way, for example I haven't explored set driven keys for hands but since they won't affect the skinning process I will consider adding them later on.

by Subr3v (noreply@blogger.com) at December 16, 2015 07:03 PM

Technical Art - V

As I mentioned before I focused my attention to rigging in the past weeks and as I've already set my eyes on an ambitious script I have decided to keep the scope reasonable and keep using the practice model I choose to start with during the labs:

Wireframe render of the model

The model topology is quite good and even though the model could lend itself to a very rigid type of deformation I will pretend the model is actually just a placeholder for a human like character (so that further thing could be explored in the future such as animation and skeleton re-targeting). I think this fits nicely my field of specialization since by researching I have seen that some companies actually employ a base model as a template for the most common animations.

Solid render of the model

by Subr3v (noreply@blogger.com) at December 16, 2015 06:48 PM

December 06, 2015

ScummVM News Headlines

Another Broken Sword by Fans for Fans

The Templars are back in this fan-made game of the Broken Sword Series! George comes back to discover the origin of a mysterious letter he received about Nico's death, and uncover the whereabouts of the modern day Templars once again...

The ScummVM Team is proud to announce that the fan-made game Broken Sword 2.5: The Return of the Templars is now playable in ScummVM using the latest daily builds, and is ready for testing.

Please report any bugs as well as unknown versions you find in our bug tracker, following our bug submission guidelines. Any screenshots of your playthrough are as usual welcome.

Many thanks to the wonderful mindFactory team who created this great sequel, and shared the original source code with us! The game can be found for free here.

by md5 (nospam@scummvm.org) at December 06, 2015 09:00 AM

November 27, 2015

Sven Hesse (DrMcCoy)

xoreos Not-Thanksgiving 2015

xoreos is a FLOSS project aiming to reimplement BioWare’s Aurora engine (and derivatives), covering their games starting with Neverwinter Nights and potentially up to Dragon Age II. This post gives a short update on the current progress.

Note: This is a cross-post of a news item on the xoreos website.

The end of the year is approaching fast, and just like last year, I want to use this time for some retrospection.

First of all, what happened in the last year?

  • berenm added support for building xoreos with CMake, by the way of parsing the automake files used for the autotools build system. This way, xoreos can now be built with either CMake or autotools. I was skeptical at first, especially since I harbour no love for CMake, but it is working reasonably well and I am quite happy with it. In hindsight, I was wrong to reject this pull request for so long.
  • I focused on supporting all the different model formats used in the Aurora games, and then I made all the games display their in-game areas with objects.
  • xoreos adopted the Contributor Covenant as its Code of Conduct, in the hopes that it helps foster a friendly and welcoming community.
  • The big one: our first official release, xoreos 0.0.2, nicknamed “Aribeth”.
  • I overhauled the script system, making it more generic. This way, I was able to apply it to all targeted games, except Sonic Chronicles: The Dark Brotherhood (which doesn’t seem to use any scripts at all). This included figuring out and implementing four new script bytecode opcodes: two for array access in Dragon Age: Origins, and two for reference creation in Dragon Age II.
  • I implemented reflective environment mapping for Neverwinter Nights and the two Knights of the Old Republic games.
  • I added a new tool to the xoreos-tools package: xml2tlk, which can recreate TLK talk table files out of XML files created by tlk2xml.
  • With these changes, I decided to push out xoreos 0.0.3, nicknamed “Bastila”.

This is all old news, more or less already discussed in previous blog posts. However, since then, I added yet another new tool to the xoreos-tools package: ncsdis. It’s a disassembler for NCS files, the stack-based compiled bytecode of the C-like NWScript, BioWare’s scripting language used throughout their Aurora-based games.

It basically replaces the disassembler within the old OpenKnightsN WScript compiler, with various added benefits. I’ll write a bit more about this tool in the near future, so for now I’ll just leave you with an example assembly listing it can produce, as well as a control flow graph it can create (with the help of Graphviz). As you can see, it already groups the instruction by blocks and subroutines. It performs a static analysis of the stack (to figure out subroutine parameters and return types) and it also analyzes the control flow to detect assorted control structures (loops, if/else). I plan to grow it into a full-fledged NWScript decompiler.

Additionally, I also added support for BioWare’s Neverwinter Nights premium modules, like Kingmaker, to xoreos.

On the documentation side of things,

  • I added comments and documentation to various files in the xoreos sources, hopefully making them more understandable and useful for potential new contributors and otherwise interested people. Considering how awful my memory is at, this is also a kind of future-proofing.
  • Farmboy0 added “research” subpages for various games on our wiki, filling them with information about their workings.
  • I extended our TODO list considerably.
  • I added an example configuration file, and extended the documentation on the wiki on how to compile and run xoreos.
  • I wrote man pages for each tool in xoreos and for xoreos itself. I also added the former to the wiki.

Phew! This is again a bigger list than I had anticipated. This wouldn’t have been possible without these people, for whom I am thankful:

  • I am thankful to berenm for providing the CMake bindings, despite my grumbling about it.
  • I am thankful to Supermanu, for continuing on chipping away on the Neverwinter Nights character generator.
  • I am thankful to Farmboy0, for working on xoreos’ Jade Empire engine and researching game internals.
  • I am thankful to mirv, for continuing with the huge task of rewriting my naive OpenGL code.
  • I am thankful to Coraline Ada Ehmke for creating the Contributor Covenant.
  • I am thankful to all the people in the different BioWare modding communities, for having figured out many different things already. Skywing for example, who had emailed me a few years ago about certain NWScript issues, issues I recently stumbled over again.
  • I am thankful to fuzzie, for giving me pointers on the NCS disassembler/decompiler.
  • I am thankful to the GamingOnLinux people, who do a lot of work reporting on all sorts of Linux-related gaming news, and who so graciously mirror my xoreos blog posts.
  • I am thankful to kevL, for notifying me of issues with xoreos’ build system on configurations I hadn’t thought about.
  • I am thankful to clone2727, for putting up with rants and ravings.
  • I am thankful to all the people who told me when I was wrong, for example when I wrongheadedly silenced clang static analyzer warnings, without understanding what I was doing.
  • I am thankful to everybody else who gave me hints and tips, taught me tricks and procedure, showed me new things, old things, forgotten things, broken things.
  • I am thankful to all the people who are not angry with me for forgetting them, because they are aware that this is not meant as a personal slight ;).

Now that I have these mushy feelings out of my system, here’s hoping for another great year! :)

And like always, if you want to join our effort, please don’t hesitate to contact us!

flattr this!

by DrMcCoy at November 27, 2015 02:26 AM

November 04, 2015

Paul Gilbert (Dreammaster)

The intricacies of disassembling RTLink/Plus

Finally, after many years of half-hearted attempts, I've finally rewritten my RTLink decode tool practically from scratch to handle disassembling the RTLink/Plus overlay management used by the later Legend entertainment games. See rtlink_decode for the result. The original version of the tool was pretty dodgy, and pretty much hardcoded to only handle the MADS games (Rex Nebular, Return of the Phantom, and Dragonsphere). In this posting, I'll go into more detail of what RTLink/Plus was for those who may be interested.

In the latter days of DOS gaming, game developers started running into a problem. Namely, that their executables were starting to hit the limits of main memory. Not every game could, or would, take advantage of scripting game content, so having all the game logic in the main executable caused the size to bloat. So what to do if your executable was now too big to fit in memory? This was the problem RTLink/Plus was designed to solve.

RTLink is essentially an overlay manager. It splits a program's compiled code into multiple different segments, and allows them to be loaded in as needed, and then replaced when code in other segments needs to execute. RTLink can handle recursive segments, with individual segments split up into their own set of swappable sub-segments. It also allows for multiple different "loading areas" in memory that can independently have their own set of segments. See this article for more general information about RTLink.

Before I go into more details of the problem this posed for disassembly, let's go over how RTLink implements the overlay manager in code. So far, I've encountered three different variations on RTLink being used in executables. What I'll call variation 1 & 2 seem to be the most common form of RTLink in games I've examined. When a program is compiled with either of these versions of RTLink/Plus, one of the segments in the code will contain the RTLink logic, as well as two main areas: the dynamic segments and the function thunks.

The segment list is a list of the dynamic segments within the application. It contains the following information:
  • The segment in memory where the dynamic segment should be loaded
  • Whether the segment is stored in the application or a secondary overlay file (Variation 1 only, version 2 only ever uses the executable).
  • The file offset and size of the segment
  • The number of relocation entries the segment has; Variation 1 only. Variation 2 has it as part of the starting header for the segment pointed to.
When a segment is needed, the above details are used to read the segment's data from file, and load it into the correct place in memory. The data for a segment consists of two parts: an initial header area, and the date/code for the segment. For variation 1, the header area simply consists of a list of relocation entries. Whereas for variation 2, the details of segment size and number of relocations are provided in a header at the start of the segment, before the relocations list.

A segment's relocation entries are used for the same purpose as relocation entries in a standard application - executables can be loaded at different locations within memory, so all segment references need to be relative to the starting point of where the program is loaded. By keeping the relocation entries for each dynamic segment together with the segment data itself, it's easier for RTLink to apply any needed segment adjustments each time a dynamic segment is loaded.

This is fine to handle shifting the segments in and out of memory, and allow them to have valid memory references, but what causes them to be loaded? The answer is the method "thunks" area of the RTLink segment. When dealing with dynamic segments, you can't just do a far call to some offset in the area of memory segments are loaded in.. you couldn't be sure that the segment you want is actually loaded, or still in memory and not unloaded by some other segment. For this purpose, the thunk list is present.

For every method in a dynamic segment that is referenced by any other segment, a thunk/stub method is created. These consist essentially of the following: a call to the RTLink manager to load the correct segment for the method, a far jump to the method in the correct memory location in the loaded segment, and a following 16-bit value specifying which segment the thunk is for. This way, the thunk method acts as a wrapper, ensuring the correct segment is loaded and passing control to the method to execute.

For variations 1 and 2, the thunk methods have some minor differences, such as version 2 using far calls to the RTLink segment loading code, and having an optional word after the segment index. The segment selector in the far jump call is also already loaded with the memory segment in variation 1, whereas in version 2 it's normally 0 initially, and then set to the correct segment when the thunk method is called. This allows variation 2 to dynamically load the segment in different places in memory, whereas variation 1 is limited to a single specific loading point.

The RTLink segment loader method also mucks around with the stack to push a new intermediate return address on the stack for when the method that's jumped to finishes. This return address points to a code fragment that also handles the case where a method in a dynamic segment calls a method in another one.. in that case, it handles reloading the original segment, so that the original caller's code can be safely returned to.

Put altogether, this scheme allows programs of practically any size needed. As the program grows, the code simply needs to be split into more and more dynamic segments which will get loaded only when needed, and remain on disk when not. Great for having big programs, but not so great for those of us interested in reverse engineering the game by disassembling the executable.

There were several problems to be solved for disassembling such games, which I'll go into now.

A standard IDA disassembly doesn't have all the code

Well, it wouldn't. If you try to disassemble an RTLink/Plus compiled game, IDA will give you an error about unused data at the end of the executable. This will be for one or more RTLink segments. Additionally, as previously mentioned, some of the code for the program can also be stored in a separate OVL (Overlay) file.

Well, I could just load the raw data for them into the disassembly, right?

Well, no. That wouldn't help much, because of all the thunk methods. They all have their references to the same area of memory where segments are expected to be loaded. If you were doing things manually, you'd need to get the details of each segment from RTLink, manually load the code and/or data into new IDA segments, and then manually adjust the thunk methods to point to those methods.

You'd also need to worry about the dynamic segment relocation entries. If you manually loaded the code for a segment, you'd have to read the list of relocation entries for the dynamic segment and manually adjust each relocation entry within the segment. Segment selectors may point to code within the segment (or another sub-segment within the loaded overall RTLink segment), to a low memory area of the executable that remains static in memory, or to the data segment (at a higher memory segment). All in all, you'd have to be extraordinarily patient to all that by hand.

So that's why you wrote rtlink_decode, right? That's what it does?
Yes and no. A bit part of what it does is indeed doing the above to create a new executable suitable for disassembly. This includes laying out all the dynamic segments sequentially (without their segment headers and relocation lists), handling relocation fixups, and the thunk methods adjusted to point to their methods in the decoded executable. However, another problem crops up in the handling of the data segment.

In my experience with RTLink, I've come across across two types of data segments:
  1. In the case of the later Legend Entertainment games, the executable has a single RTLink segment, with the remainder of the segments coming from an OVL file. The single executable segment is for the main data segment as well as a few other miscellaneous segments.
  2. In the case of the MADS games, the data segment isn't an RTLink segment, but all the RTLink segments follow it in the executable.
In both cases, we have a problem doing a proper disassembly. Executables are normally expected to have the data segment at the end of the program, because the data segment may be longer than the end of the executable. For example, a game's data segment may only have 1Kb of pre-set values which are stored in the executable, but it still requires 40Kb of unallocated/uninitialized space. That's why you'll frequently see, when you do a disassembly of a program, areas at the end of a data segment with '?' mark values, indicating the memory isn't part of the executable, so doesn't have any specific value when the program starts.

So if we did just lay the segments end to end, the data segment, coming before other dynamic segments, would end up being shorter than it should be, and a lot of the references to data within it would end up wrapping onto the following dynamic segments in the reworked executable. To avoid this,  the rtlink_decode tool ensures that the data segment falls at the end of the generated executable, after all the other segments. This, however, causes it's own share of problems. All the existing references to the data segment refer to where the data segment was expected to be loaded in memory, not to where the data segment actually is in the new executable. Because of this, all the references to the data segment in the executable have to be adjusted accordingly.

Ouch! Sounds fiddly.

It is. And took a lot of messing around to get right. Even then, that's not the entirety of the picture. For Companions of Xanth, the Legend game I used for testing when rebuilding the tool, the data segment has some extra gotcha's.. It contains segment references into the middle of the memory area RTLink segments are loaded into. Presumably these are used in some special controlled circumstances when a specific segment (or segments) are loaded to access particular data. But it's impossible to know without understanding the game a lot better. 

Worse, the presence of the references were screwing up some of the loaded dynamic segments in the disassembly, causing them to be split in half. To handle this, the tool explicitly looks for such "bad" references in the data segment, and removes the relocation entries for them. This way, the value in the data segment will remain as a static word, and the segments don't get incorrectly split up. The user can always then later manually set up a pointer to an appropriate segment if they wish. This handles the bulk of such errors, but Xanth at least, there are still references in the low part of the executable (that remains static in memory) to locations within the RTLink segments. Since I can't know which particular RTLink segment is meant to be loaded when the code they're in is called, these few remaining references will have to be later manually adjusted as well.

So that's it?

Yep. After all these years, I'm finally able to generate a (mostly valid) "decoded" executable, and produce a clean disassembly of Companions of Xanth. I also, initially, had two separate versions of the the tool, one the old hacky version for MADS games, and the legend variation for Legend-style RTLink usage. I've since updated my tool to properly handle MADS games, so now there's only the single rtlink_decode tool, and it can handle both variations 1 and 2.

Oh, wait.. what about the 3rd variation you mentioned?

Ah, yes, I didn't really get into that, did I. This version seems to be somewhat different than the other two variations. In this case, the RTLink code is stored in a separate rtlinkst.com file, and then loaded into memory. It then shifts part of the program downwards in memory, and uses it's own relocation table to manually process relocation entries on the shifted code. This variation is proving tricky to disassemble, so whilst I have located the segment list, I still need to:
  • Figure out how relocation data is encoded. I think I've located the correct data in the executable, but the code RTLink uses to update relocation entries is pretty nasty and overcomplicated.
  • How much of the start of the executable to remove so that the produced executable doesn't have any of the old code at the start of the executable that gets overwritten
  • Find the thunk methods, and see whether the existing code will handle them.

Hopefully I can quickly figure out the remaining details for the third variation soon. The goal is to have a tool that both myself and others can use in the future to help them disassemble any game that used RTLink/Plus. Then no-one else will have to go through all the frustrations that I did trying to deal with this %#@! thing.

by Dreammaster (noreply@blogger.com) at November 04, 2015 06:32 PM

October 31, 2015

Paul Gilbert (Dreammaster)

Sherlock Testing Resounding Success

Hi everyone,

It seems like the testing of the Sherlock games has been a success. There were lots of bug reported, and all the ones reported so far have been fixed. The foreign language versions haven't all been fully tested yet, but hopefully now the immediate crashes with conversations and inventory in both Serrated Scalpel and Rose Tattoo foreign language versions have been fixed, and the rest of the games can be tested. I'd like to thank everyone who's tested so far for your efforts, and feel free to post any more bugs you come across. Though hopefully there won't be too many more to find :). And if one else has copies of either game, particularly different foreign versions, any other testers would be appreciated.

Right at the moment I'm at the sweet point where all the outstanding bugs for Sherlock have been resolved, so unless new ones come in, I can turn my attention to other things.

So, whats coming next for me? Several things:

Serrated Scalpel 3DO

Serrated Scalpel 3DO still isn't completable. There are some areas, such as the darts game to fix up, and there are still some differences in sprite positioning that would need to be accounted for. It's somewhat constrained by the fact that we don't have any original source for it, and I don't have any experience with reverse engineering 3DO games. It may simply be a case of do as best we can with hardcoded fixes as necessary.

The 3DO version also has a few missing things compared to the PC version; notably it lacks the journal the PC version has. A "nice to have" for the future would be to reintroduce it, so that the 3DO version could be the definitive version of the game, containing all the PC version functionality as well as the video for all conversations. We'd likely create a tool that extracts necessary graphics for UI buttons and the journal background from the PC version, and produce a Dat file that ScummVM can use automatically when playing the 3DO version.

RTLink Overlay manager

Next, there's the RTLink/Plus overly handling in Companions of Xanth. I'd previously had some luck writing a tool to process Rex Nebular and create a flat executable with all the segments suitable for disassembling, but doing the same for Companions of Xanth proved elusive. Over the years I made several attempts, but none bore fruit. Until now. As of yesterday, I was finally able to write a new version of the tool that successfully generated a flat executable that could be disassembled. So one day, after a great deal of disassembly work, ScummVM may support the game.

My only disappointment is that RTLink/Plus seems to have had quite a number of variations. Rex and Xanth's RTLink mechanism were fundamentally similar, with all the RTLink code, segment list, and method thunks/stubs in the executable and/or overlay file. For several other games with RTLink that I tried, however, they seem to use a bizarre alternate method where a file called 'rtlinkst.com' is loaded, then an '.RTL' file for the game, and finally only then the game executable. Which means that my tool doesn't work with them, and I'd need to figure out this new mechanism from scratch if I want the tool to be general-purpose enough to handle any RTLink game anyone might want to use it on in the future.

Guess that can be another long-term project to muck around with. Hopefully it won't take as long as it did to finally get Xanth properly disassembled. :). I'll probably make another posting in a day or so about RTLink in more detail, for those that are interested.

Might & Magic, World of Xeen

Next there's my work on re-implementing Might & Magic - World of Xeen (and Clouds of Xeen, Dark Side of Xeen, and Swords of Xeen). With some free time last weekend, I finally returned to working on them, and likewise was finally able to properly disassemble the  algorithm the original used for scaling. So as of now, sprites are now correctly scaled, as before I was only using a rough guess scaling code I'd nicked from another game engine. I've also fixed some other drawing bugs for drawing outdoor areas (outside town). So as of now the game scenes now display properly! :)



That's right, you can now walk around, fight monsters, go visit the various buildings in town, and even leave the town! In fact, most of the functionality for the games are already implemented. Apart from lots of testing and minor bugfixes that will be needed, only the following major areas remain to be implemented:

  • Introduction/ending sequences for the games
  • character management, and title screens.
  • Sound. I'm hoping I can simply slot in one of ScummVM's audio decoders without much further work.
  • Savegames

At the moment I'm concentrating on getting World of Xeen (which combines Might & Magic 4 and 5 together) working. But then afterwards I'll implement separate support for 4 and 5, as well as for Swords of Xeen. It might even be feasible to handle Might and Magic 3 - Isles of Terra as well, since I'm given to understand the engines are nearly the same.

Those interested in following the progress can see it at the brand-spanking new RogueVM Github account. That's right; after all the years of idle talk, I've finally set up a place to properly store RPG related game engines. No website yet, but at least it's a start. :) I'll likely spend the near-term focusing mostly on finishing support for the game before I move onto any other adventure games, considering how far along the engine is already.

Return of the Phantom

Strangerke has put a lot of work recently into implementing scene logic for Return of Phantom, the next MADS game that was published after Rex Nebular. There are quite a few stubs for missing engine functionality that was added in though. So when I do return to working on adventures, it will likely be to assist him in completing the game.

DreamMaster.

by Dreammaster (noreply@blogger.com) at October 31, 2015 04:01 AM

September 27, 2015

Matthew Hoops (Clone2727)

The Future

On the off-chance you didn't recognize the image from my last post, it was part of an animation from Buried in Time. And now you can find the source for running the game in ScummVM over here. And, yes, it's completable.

I'll fill in more details on the blog when I get a chance, but I think trying it out is probably a better way to show off what's been done.

Oh, and I went a little overboard with compatibility on this title. Not only is the 24-bit one working, it has full compatibility with the 8-bit game resources too. (This is the ultimate purpose for that Cinepak dithering I spoke of last year.)

Much thanks to Presto Studios yet again for making all this possible and providing the original source code!

by clone2727 (noreply@blogger.com) at September 27, 2015 12:45 AM

July 06, 2015

Paul Gilbert (Dreammaster)

Rose Tattoo is in progress

Hi all,

Work is progressing well on Rose Tattoo, and as of tonight I hit a major milestone.. the entire game intro sequence is now completable. See the screenshots below:



There are still some minor graphic glitches at various points, and one of the scenes which is a double-side scene isn't properly scrolled horizontally yet, but even so, it's a great step forward in supporting the game. We're actually lucky in that Rose Tattoo implemented all of the introduction using standard game scenes. So it saved a lot of effort implementing manual introduction code like had to be done for Scalpel.

Now that the introduction is working, more or less, I'll be devoting more time to implementing the game-play. I'd already been spending some of my working on it, so some interaction is possible.. you can look at objects, open up the inventory, and conversations with characters are partially working. The game map is also already implemented, so you can get to other game locations as well.

On another subject, I had good luck implementing the original EA logo at the start of Serrated Scalpel. I was able to complete support for it in the TsAGE engine, and then used that as a basis for copying necessary code into the Sherlock engine. With some most welcome assistance from others, the EA logo at the start of the game now displays when you start the game, just like the original does.

Finally, on yet another tack, there have been some promising first steps towards supporting the 3DO version of Serrated Scalpel by m-kiewitz, with some assistance from clone2727.  The 3DO was a superior version of game, and included 16-bit color, video portraits, and full speech for every conversation in the game. Supporting this would be great. It would be nice if, one day, the 3DO version could be re-released with ScummVM, so a wider audience could properly enjoy the game.

by Dreammaster (noreply@blogger.com) at July 06, 2015 04:09 AM

May 22, 2015

Paul Gilbert (Dreammaster)

Happy Birthday, Sir Arthur Conan Doyle

Hey everyone.

Looking back it seems, to my chagrin, that it's now been over a year since my last news posting was over a year ago. Whoops :P. Not that I haven't been keeping busy over the last year or so, with the release of Voyeur, Amazon - Guardians of Eden, Rex Nebular (finally), and of course, the newest game.. The Lost Files of Sherlock Holmes: Case of the Serrated Scalpel.



Many thanks go to EA for providing us access to the original source for this game. Also to forum user sirlemonhead, and to James Ferguson, who patiently over the last few years tried to make this happen. I've always been a big Sherlock Holmes fan, so it was fun to work on this project.  It feels fitting to merge the game into master on the 22nd May, which is the birthday of the character's creator, Sir Arthur Conan Doyle. The engine isn't quite ready for serious testing yet.. it's still missing music playback, and there's also a starting logo animation that's not present. It should be finished soon, though, so expect to see an official testing announcement in the near future.

So.. as things stand, what I am up to right now?

The Logo
Apart from the game proper, one of the more interesting things about the game is at the very beginning, where the publisher EA logo is shown. This logo display was actually implemented in a separate executable using the TsAGE engine, of all things. Original source for this couldn't be located, so it means that I'm having to reverse engineer it. Luckily, since we've already had experience with several other TsAGE titles, I've been able to make excellent progress in figuring out all the various TsAGE classes and their methods within the executable.

At the current point in time, I've identified the bulk of the core TsAGE classes, and the custom logic for the "game", which is contained a single scene class. This scene class consists of several scene objects, a few palette containers, and an "Action" class for coordinating what happens in the logo display. There's only a minor variation in how object sprites are loaded compared to the games that I still need to figure out.

I've already started implementing a new sub-module within TsAGE for the game logo. Once I finish that, it will be easier to analyse all the movement and frame changes of the images with the scene.  Hopefully, based on that, I'll be able to simulate a similar sequence in our new Sherlock engine using the bare necessities from TsAGE - likely just the RLB archive manager and sprite loader. Particularly given the thoughtfulness of EA in providing us access to the original source, it would be nice to give them (the company) proper attribution by showing their logo just like the original game does.

The Sequel
Apart from that, we have also been given access to source for the sequel, The Case of the Rose Tattoo. Implementing this is likely to be much more challenging, as the sequel changed over to a 640x480 display, and significantly altered the user interface. As such, it's likely it will need a lot of re-factoring of the code base to add support for it to the existing engine. If you thought a lot of re-factoring was done during the pull request, you 'aint seen nothing yet. :)

I'm also somewhat constrained by the fact that the original uses DOS4GW and a 32-bit code segment. Whilst we do have the original source, I need to be able to run the game in DosBox so I can actually see the code running, and check registers and memory contents at given points in the program. I've had some significant trouble with the DosBox debugger, trying to set breakpoints in the code so I can inspect the game's state.  Doing so crashes either crashes DosBox, or the game executable, or the breakpoints simply aren't hit.

So far, I've only done some preliminary loading of scene resources in the second game, and the lack of a way to display the program state meant that I had to take a more laborious route of poring over the various resource structures and scene loading code in both games, to try and figure out what the differences were between the two, so my code can support it. Likely, as I proceed with implementing more of the game, this will cause real issues that will make finding bugs a lot harder.

World of Xeen
It's been somewhat on a back-burner since I started work on the Sherlock Holmes games, but I had previously made real progress on re-implementing World of Xeen using the ScummVM framework. See below:


As you can see, I have much of the game interface implemented. You can move around, fight monsters (with a few minor glitches), and even leave the town. There are really only a few main areas left to implement, which includes sound support, logic for all the various spells, savegames, and the intro/ending cut-scenes. I probably won't return to working on it until after Rose Tattoo is finished, though. But when I do, I don't anticipate it will take long to finish the remaining areas, and then it would simply be a matter of playing the game through in earnest, identifying and fixing minor bugs as they're identified.

Of course, as an RPG, World of Xeen is a bit outside the scope of ScummVM proper. At that point, it may be time to finally launch the RPG sister project Strangerke and I have been wanting to do. :)

by Dreammaster (noreply@blogger.com) at May 22, 2015 12:09 PM

January 25, 2015

ResidualVM News Headlines

ResidualVM 0.2.1 - "Działające Napisy" released

Version 0.2.1 is a bugfix release for 0.2.0. It fixes a crash when using subtitles in the Polish version of Myst III, and an IRIX port was added.

As always, the latest release is available from our downloads page.

by bgK (nospam@residualvm.org) at January 25, 2015 12:00 AM

December 31, 2014

ResidualVM News Headlines

ResidualVM 0.2.0 - "Deliverance" released

We are proud to announce the release of a new version of ResidualVM, bringing Myst III: Exile support, more than thirteen years after its original release.

Initial work towards adding Myst III support began back in 2009 as a side project. A work in progress version of the engine was included in ResidualVM two years later. The game became completable in 2012, but only now do we feel confident enough to release a stable version providing a feature complete experience.

Additionally, some bugs have been fixed in Grim Fandango, and game data verification has been added on first launch. So that you'll know if your game data was copied correctly from your CDs.

Whether you are using Windows, Linux or OS X, you can check out our downloads page, get yourself a copy of ResidualVM 0.2.0, and decide later if you'd rather visit the land of the dead or the land of a revengeful trapped man. The changes in version 0.2.0 are detailed in our NEWS file. Instructions to setup the games can be found on our wiki.

As usual, even though we have tested the games thoroughly you might encounter game-breaking bugs. So, please save often and report bugs to our bug tracker.

Our thanks go to Presto Studios, for releasing such a great game, and to the people involved with testing ResidualVM over the years, allowing us to provide high quality releases.

2015 already looks like a promising year for ResidualVM, thanks to the ongoing effort for adding Escape from Monkey Island support.

by bgK (nospam@residualvm.org) at December 31, 2014 12:00 AM

December 23, 2014

ResidualVM News Headlines

Playtesters needed for testing of Grim Fandango and Myst III for 0.2.0 release

We are planning to release ResidualVM 0.2.0 with support for Myst III as our second supported game. The Grim engine has had quite a few changes since 0.1.1, so to avoid any big showstoppers for Grim Fandango, we need your help.

We need people to play through Grim Fandango and Myst III, preferably testing all the optional parts that aren't required for completion too. If you are interested, download our 0.2.0 pre-release builds (not the unstable builds), and start playing.

Any bugs should be reported to our issue-tracker on GitHub, and when you complete, you should post in our forums.

Details can be found here.

by aquadran (nospam@residualvm.org) at December 23, 2014 12:00 AM

November 30, 2014

Thierry Crozat (criezy)

Broken Speech

Yes, another Broken Sword post. In previous posts I wrote about my initial work to add support for the mac version of the Broken Sword game in ScummVM and some more work I did to fix graphical glitches with this version. At that point the game was working fine for me. But soon, we got a report on the forum that the speech was not working. Obviously it was working for me, I would have noticed if it wasn't. So what the heck?!

Bug reports are good. They stop me getting bored. And they show that other users have the mac version of Broken Sword and benefit from my work, which is also gratifying. So let's look at that issue. And to do so, first let's rewind to my first post. I wrote that I assumed the files with the same name (including the extension) as the files of the Windows version where in the same format, and in particular used the same endianness. And the files with a different extension were big endian in the mac version and little endian in the Windows version. That proved mostly correct (a few resources had been left as little endian data in files otherwise converted to big endian).

Except that wasn't correct. So why did it work? Because I had been lucky. When I initially worked on supporting that game it looked like my guess was correct, and I therefore made quick progress as I was not distracted by some strange behaviour. But...

Let's start the story from the beginning:

In the Windows version the speech is stored in a file named speech.clu. There are actually two such files, one on each CD, and they store the speech as 16 bits compressed mono wave data. And as you can expect the data is little endian.

In the Mac version, the files have the same name (speech.clu). So in my initial implementation I assumed the speech data was little endian in the mac version as well. And it worked... with the version I have (the French version). Obviously it didn't work with the version of the user reporting the bug (the English version) since the user reported hearing static noise instead of speech.

The two files (Windows and Mac versions, both English) have the same size:


But opening them in an hex editor shows differences:

Do the differences remind you of something?
If not go back and read again the first two posts in this Broken Sword mac support series.

Before looking at the differences, I will give a short explanation of the speech file format.
The speech files are a collection of sound resources. Each resource contains the wave data for spoken sentence and is organised as follow:
4 bytes: 'data' (i.e. hexadecimal values 64 61 74 61)
4 bytes: number of samples
n bytes: wave data (16 bits mono)

So quite simple, but maybe no as simple as you might think. If you are thinking that n is the number of samples multiplied by 2 (since each sample takes 2 bytes) you are wrong. Because the data is compressed. This is not really important for now so I will keep the description of the compression for later.

What is important here is that we can see that the first 4 bytes after 'data' are identical (in the image above hexadecimal values 8E E6 01 00 - which, since we know it is little endian, means 0x0001E68E = 124558 samples). But the values that follow are obviously a series of 2 bytes values for which the bytes have been swapped.

At this points, here is a small reminder in case you are not following me and did not go back to my previous posts: big endian and little endian are conventions used to interpret the bytes making up a data word (more at http://en.wikipedia.org/wiki/Endianness).  For example 42 in hexa is 2A, or when using two bytes 002A. When using the big endian convention, this would be stored as 00 2A. But when using the little endian convention this would be stored as 2A 00.

So this should be obvious to you now that both the Windows and the Mac version store the number of samples of the sound resource as little endian values, but in the mac version the data samples themselves are stored using big endian convention. Why mix endianness in the same file? Why do this for the mac English version but not the mac French version? Don't ask me, I have no idea.

Since some mac version use little endian and others use big endian, we need to know which one it is. Does it depend on the language, i.e. all French versions use little endian and all English versions use big endian? Maybe. But I don't trust statistics on a set of two samples. And what of the German versions?

Therefore we decided to use a heuristic to find out if the mac version the player has uses big endian data or little endian data. The heuristic works by computing the average difference between two consecutive samples (using absolute values). Using the assumption that a sound wave is smoother than picking values at random, the lower average difference is considered to be the correct endianness.

If we take the 13 samples from the example image above, assuming big endian for the mac version gives us the following curve:


The average difference value from one sample to the next is 425.17.

If we assume little endian data the curve is:

And the average difference value is 9344.75.

So in this case the heuristic tells us the data is big endian, which it is. Of course in the actual source code we use more than 13 samples to get a statistically valid heuristic value.
The original patch that adds the heuristic code can be found in the patch tracker: https://sourceforge.net/p/scummvm/patches/956/

But the story does not ends here. A new bug report very similar to the original one (i.e. speech sounds like static noise) was reported a few months ago. It was quite obvious that the heuristic did not work for that user and the wrong endianness was used. Why is that? It turns out there were several issues with the original heuristic code.

And that is where explaining how the speech data compression works will help to understand what was wrong. The data for one sound resource is broken in blocks, each one starting with a number of samples followed by the sample values. When you have consecutive samples with the same value it uses a negative size and the value is stored only once.
So for example the following sequence:

    0 0 0 0 0 1 2 3 4 5

would be stored as (where the brackets indicate the blocks):
    [
-5 0] [5 1 2 3 4 5]
All those numbers (number of samples and sample value) are stored on 2 bytes.

Here is the original source code (if you don't see the source code visit the blog as it may not be visible in RSS feeds).

I will not show the uncompressSpeech() code (yet). The only thing you need to know is that it uses the value of _bigEndianSpeech as either big endian or little endian data. So what the code above does is get the data assuming little endian data and then compute the heuristic value for the samples it gets and for the same samples to which a byte swap is applied, which should be the value we would get assuming big endian data. Right?

Wrong! This heuristic forgets something: the data is compressed, and when uncompressing it always assume little endian when reading the number of samples for each block. But if the data are big endian this number would be different and the blocks would have different sizes, and because the block boundaries would be wrong it would cause number of samples to be interpreted as sound samples and some sound samples to be interpreted as number of samples.

For example let's look at the resource of 10 sample with the compressed data -5 0 5 1 2 3 4 5.
Assuming the data is stored in big endian, in hexadecimal values with two bytes per value this give us: 80 05 00 00 00 05 00 01 00 02 00 03 00 04 00 05
If we read this with the heuristic above, because the number of sample is always read assuming little endian data we get 80 05 = 1408 samples instead of -5 for the first block. So the code will get the following samples: 0 5 1 2 3 4 5 followed by 4 garbage values read beyond the end of the resource instead of getting 0 0 0 0 0 1 2 3 4 5. So if the data are stored using big endian, the heuristic values gets biased. Almost always it still gets a lower score as reading it as little endian though.

The solution here is to call uncompressSpeech() twice, once assuming little endian and once assuming big endian.

But there is still an issue with this heuristic.
When reading with the wrong endianness, since we may read the wrong length, it may for example be a big negative number. Because we are using a relatively small finite number of samples, statistically we could end up with a small heuristic value because it has a lot of consecutive samples with the same value. For this reason I made an additional change to skip consecutive samples with the same value when computing the average difference.
After that commit the value for the heuristic with the wrong endianness is consistently about 21000, i.e. 1/3rd of 16 bits integer range (65 535 / 3 = 21845). As noted by wjp:  the average absolute difference between two random numbers drawn independently from a uniform distribution between 0 and N is indeed N/3. So this is quite reassuring.

So everything was correct after this change? No, that would be too easy. We want complex puzzles spanning several rooms, not some kind of hidden objects game. And the user reporting the bugs confirmed the bug was still present after that change. So let's look at a different room, or rather a different function.

Here is the code from uncompressSpeech():
Note something relevant? No? Look closer. You see it now? Yes, this function always give us the sound data in little endian format, whatever the endianness in which it is stored, and more importantly whatever the endianness of the computer on which the code is run.

And if you look at the heuristic code above, it assumes it gets data in the native endianness (i.e. the endianness of the computer on which the code is run). So when running on a computer using big endian convention the heuristic was wrong. Let's look again at our previous example and how it was interpret on a big endian computer:
   Read with the correct endianess: 0 1 2 3 4 5 (duplicate values have been removed)
   Was interpreted as: 0 256 512 768 1024 1280

   Read with the incorrect endianess: 0 1280 256 512 768 1024 1280
   Was interpreted as 0 5 1 2 3 4

So in the heuristic code, on a big endian computer we need to swap the bytes of the two set of data to get the correct value. This brings us to the final code, in which the heuristic computation was also moved to a separate function to avoid code duplication (since it is done twice):

The user reporting the bug confirmed he was using ScummVM on a big endian computer (a G4 mac) and that the speech was correct after that final change.

by Thierry Crozat (noreply@blogger.com) at November 30, 2014 09:38 PM

November 29, 2014

Sven Hesse (DrMcCoy)

xoreos Not-Thanksgiving

I elaborate on the current state of the xoreos project and what/who I am thankful for in this new post on the xoreos blog.

flattr this!

by DrMcCoy at November 29, 2014 03:31 PM

November 23, 2014

James Woodcock

My ScummVM Music Enhancement Project & ScummVM feature in Gamer.no Article

My point and click adventure soundtrack recreations have featured in one of Gamer.no's articles.

by James Woodcock at November 23, 2014 10:18 AM

September 28, 2014

Thierry Crozat (criezy)

How it continued

In my very first post on this blog I wrote how I came to be involved with the ScummVM project by adding support to the mac version of Broken Sword 1. I wrote I had been lucky, and you will have to wait a bit longer to know why (yes I know, I am milking this one, but I promise I will explain it soon). I expertly avoided however to reveal that I had also been lazy. When I submitted the initial patch I knew the support was not perfect. I already mentioned it lacked support for AIFF music (and I will take this opportunity to correct myself: apparently the support was added by eriktorbjorn, at least according to the history on github, and not by sev as I mistakenly wrote in my first post). But more importantly there were graphical glitches. Yes! GRAPHICAL GLITCHES! Oh, the horror! And I can't even claim I had not noticed them. That would mean admitting I was blind (or at least color blind).

The first one is visible every time you visit Nico in her apartment, which is quite often (just a shame you can't use that big bed). Notice anything wrong (no, not the bed)?

George, don't leave! Have you seen what is waiting for you out there? A corridor painter in red! Stuff of nightmare! And the psychopath who painted that might still be lurking in a corner!

Just in case the image above appears normal to you, here is what it should have looked like:

No light in the corridor? I guess they forgot to pay the electricity bill.

The second glitch is even bigger, although maybe not as obvious. I had not played the game for a few years myself when I added support for it in ScummVM, and while something was bugging me during my tests I was not sure what it was initially.

Bull's Head Hill, Syria, on a murky day. The sky, the color of a swamp, was empty of any birds. And I was about to jump into the void.
And here is what is should have looked like:

A Sunny day in Syria. Maybe I will live after all. Not that it will stop me jumping though.
So what is wrong? This scene in Syria has a background parallax layer, on top of which the foreground is drawn, with transparency where we should see the background. And you have probably noticed by now that the background was not visible in the mac version.

The game sometimes uses parallax layers to give a sense of depth to the scene. When the characters move on screen, the foreground and background will move at different speed. See wikipedia if you have never heard of a parallax before.


This is the only scene in the game that has a background parallax layer. And as such it has a special logic for the draw code. Other scenes may have a foreground parallax layer however, as is visible in the video below.


The two glitches are caused by two different bugs. But they are somewhat related. The game uses 256 colors with a different palette for each scene. That means each scene defines a list of 256 colors, and then the image data is defined using the indexes (stored on 1 byte) in that list instead of using directly the colors.

The palette for each scene is actually defined in two separate resources: one that defines the palette for the scene itself and contains 184 colors (indexes 0 to 183), and one for the sprites that contains 72 colors (indexes 184 to 255). The first color (at index 0) is actually reserved for the top bar (inventory) and bottom bar (dialog options) area when the bars are hidden. It is forced to black in all the scenes, whatever the color defined in the data file. This is also the color used for the door in Nico's room. And it is used for the transparent part of the foreground image in the bull's head hill scene. And this is the index used for the transparency in the sprite data as well.

You have probably guessed it by now: the mac version does not use color index 0 for the door in Nico's room and for the transparency in the bull's head hill scene. After a bit of debugging it turned out it is actually using color index 255 (i.e. the last color of the palette instead of the first one). In Nico's apartment that color happens to be red, and in the Bull's Head Hill scene it happens to be some sort of brownish dark green. Once I knew what the problem was, it was fixed with a simple patch.

Other than that the Mac version is identical to the Windows version. It still uses the first 184 colors of the palette for the background and the last 72 colors for the sprites. And it still uses color index 0 for the top and bottom bars area and the transparency in the sprite data. So I have no idea why they made that change for the two cases described above.

Here is the code to get the palette when loading a new room. As explained above it is called twice, once for the first 184 colors and a second time for the remaining 72 colors. We force color 0 to be black. Lines 6 to 9 corresponds to the fix for the mac version, in which we also force color 255 to be black.



And here is the beginning of the draw code. As I wrote above the Bull's Head Hill, which is screen 54, has a special handling. We first draw the background parallax and then draw the screen on top, skipping pixels with color 0 (which here means transparent). On line 21 we have the fix for the mac version, for which we also skip pixels with color 255.



And that is all for today. In the next post I will speak of the speech data, and I will explain why I was lucky in my initial implementation.

by Thierry Crozat (noreply@blogger.com) at September 28, 2014 06:22 PM

September 19, 2014

Peter Bozsó (uruk) - GSoC

Testing

Hey everybody! :)

Finally, Sfinx got the point (with the English translation in parallel), that it's available for testing! :)
You can read the official announcement here.
So if you have the time and you are eager to try something new, feel free to test our new engine!

Cheers! :)

by uruk (noreply@blogger.com) at September 19, 2014 06:54 AM

September 18, 2014

Thierry Crozat (criezy)

Do you play English? Part 3

In this post I will continue to write about translating games for the ScummVM project. This is the last  part of a three parts series.

Part 3: Translate a game into a new language


Some of the games for which we released a freeware version are from eastern Europe and were not released in English. So to give them a wider audience we decided to add an English translation.

The first such game was Dragon History, a Czech game for which a GSoC student added support in ScummVM in 2009, with the help of the original developer. The game was only released in Czech and Polish originally, but German and English translations have been added. If you want to know more about this game, see the official web site: http://www.ucw.cz/draci-historie/index-en.html

Since I don't know much about Dragon History myself, in this post I will focus on two Polish games from LK Avalon. The first one Soltys, is supported since ScummVM 1.5. It is available to download for free on our web site, and in addition to the original Polish version, we have an English and Spanish translation.

The second game I will write about is Sfinx. It is very similar to Soltys in the way it works, and support for it in ScummVM was added during this year GSoC. We are currently working on the English translation and very soon (maybe tomorrow?) we intend to make it available so that non-Polish ScummVM users can test the game, report bugs and also suggest improvement to the translation.

Edit: the call for tests is now live!

Both Soltys and Sfinx have two data files named vol.dat and vol.cat. The latter is a catalog that lists the files present in the former and at which offset they start. So when the game needs a file, it can look into the catalog where to start reading it in the vol.dat file. To edit the data files however, we need to extract those. Then we can repackage them into a new vol.dat file, generating a new catalog file as well in the process. We have two tools to perform the extraction and packaging, and they work for both Soltys and Sfinx (despite some minor differences in the file format).

Once uncompressed, you will have a lot of files. All the dialogs are in a file named CGE.SAY. The hotspots names are in the files with the SPR extension. The other files can be ignored (they will be needed when repackaging the game though.

So what does the CGE.SAY look like? Here is a small portion of it that shows almost everything there is to know:

;--Anna above.
 1:22=Oh, what a nice pussy!|I would love to have one
;--Vincent in the dark
 1:31=Where's the light? I can't see
 1:32=There should be a shutter,|let's try to lift it

;======================================================================

;--Vincent about the cleaning stuff
 2:01=Cleaning? Never!|It's for the girls!
;--Anna about the cleaning stuff
 2:02=Isn't there a gentleman around?

Lines starting with a semi column are comments. There are a lot of them, which is a great help.
Dialog lines start with xx:yy as you can see above. The xx is the room number. So in the example above we have a portion of the dialogs for the first two rooms. The yy is the text number in this room.
The pipe indicate a line break. So for example the first text of the second room will look like this in game:



Simple, isn't it?
Now let's have a look at one of the SPR files, for example 02ZSYP.SPR. As the name suggest this is one of the hotspots in the second room. The start of the file look like this in the polish version:

Type=AUTO
Name=zsyp na <98>mieci

[phase]
02zsyp00
02zsyp01
02zsyp02

[seq]
 0   -2   0   0  0   8
 1    3  84   2 127  8  .OTWIERA
 1    0  85   2 127  8  .ZAMYKA

 2   -2   0   0  0   8

[ftake]
say    -2    2:5  brudny

[mtake]
reach  -2  2:7     . zsyp
SOUND  2:7 2:84
pause   -1 72
SAY    -2  2:4
NEXT   -1   0      . smiec popycha

The name is what appears on screen when moving the cursor to the hotspot. We can now also see that the file is named after the hotspot name. This makes it easy to find a file when you know the hotspot name... in Polish (not so easy when you know it in English ;) ).

The <98> is the way my text editor displays non ASCII characters using their hexadecimal value (so in decimal we have here character 152).  In this case the character is ś. The game is using the CP852 encoding (with only the example above it could also have been using the mazovia encoding, but other characters allow to make the distinction). Fortunately English does not use many non ASCII characters, so we don't have to deal with this much.

So, the polish name is zsyp na śmieci. Google translate tells me (I don't speak Polish myself) that it translates into garbage chute. So let's modify the second line in the file and see how it looks:

Type=AUTO
Name=garbage chute

[phase]
02zsyp00
02zsyp01
02zsyp02




For Sfinx, the bulk of the work was done by Strangerke and then I made a couple of passes to improve the English and fix spelling mistakes. Uruk, the GSoC student who worked on the engine, also made some modifications.

For Soltys, the Polish to English translation was done by neutron and the Spanish version is from IlDucci and The FireRed. I am currently working on a French translation as well.

The process I explained above is therefore very similar to what I explained in the previous post to improve an existing translation for Drascula:

  • Unpack the data file.
  • Edit the dialogs and hotspot names.
  • Repack.

However there is one major difference. Because the game was only released in Polish in the first place, the font data does not contain all the characters we need for other languages. For English this is not an issue, unless you happen to use a word loaned from French, such as déjà vu or café.  When translating to French however you need those accentuated characters. So there is one more step to do: modify the font data (which was done by Strangerke on Soltys).

The font is stored in a file called CGE.CFT. This is a simple bitmap font, for which each pixel is black (or another color) or transparent. So we need one bit to store a pixel. If the bit is 1, the pixel is visible, and if the bit is 0, the pixel is not visible. The height of the font is 8 pixels, which conveniently can therefore be stored on one byte (because in case you don't already know, 1 byte contains 8 bits). The width is variable, and if for example a character is 4 pixels wide, thus 4x8 pixels, its data is coded on 4 bytes. And there are 256 possible characters.

The font file starts with the width, coded on one byte, for each characters. That takes the first 256 bytes. Then the bitmap starts. Here is the start of the file for Sfinx displayed with hexadecimal values. The first column is the address (also in hexadecimal). We have 16 bytes on each line. A star denotes one or more lines that are identical to the previous line.

0000000 04 06 06 06 06 06 06 04 04 04 04 04 04 04 04 04
0000010 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04
0000020 04 02 04 06 04 05 05 02 04 04 03 04 02 03 02 03
0000030 04 04 04 04 04 04 04 04 04 04 02 02 04 04 04 05
0000040 05 05 05 05 05 05 05 05 05 02 04 05 04 06 05 05
0000050 05 06 05 05 06 05 04 06 04 06 05 03 03 03 04 05
0000060 04 05 04 04 04 05 03 04 04 02 03 04 03 06 04 04
0000070 04 04 04 05 03 04 04 06 04 04 04 04 02 04 06 06
0000080 04 04 04 04 04 04 04 04 04 04 04 04 04 05 04 05
0000090 04 04 04 04 04 04 04 05 05 04 04 04 04 04 04 04
00000a0 04 04 04 04 05 05 04 04 05 05 04 04 04 04 04 04
00000b0 04 04 04 04 04 04 04 04 04 04 04 04 04 05 04 04
00000c0 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04
*
00000e0 05 04 04 05 04 04 04 04 04 04 04 04 04 04 04 04
00000f0 04 04 04 04 04 04 04 04 04 04 04 04 04 04 03 04
0000100 00 00 00 00 1e 29 2f 29 1e 00 1e 2b 2f 2b 1e 00
0000110 0e 1f 3e 1f 0e 00 0c 1e 3f 1e 0c 00 1c 5b 7f 5b
0000120 1c 00 1c 5e 7f 5e 1c 00 ff ff ff 00 ff ff ff 00
0000130 ff ff ff 00 ff ff ff 00 ff ff ff 00 ff ff ff 00
*
0000180 ff ff ff 00 ff ff ff 00 ff ff ff 00 00 00 00 00
0000190 2f 00 03 00 03 00 14 7f 14 7f 14 00 26 7f 32 00
00001a0 13 0b 34 32 00 1a 25 1a 28 00 03 00 3c 42 81 00
00001b0 81 42 3c 00 06 06 00 08 1c 08 00 60 00 08 08 00
00001c0 20 00 38 07 00 3f 21 3f 00 22 3f 20 00 3b 29 2f
00001d0 00 31 25 3f 00 0f 08 3f 00 37 25 3d 00 3f 25 3d
00001e0 00 01 3d 03 00 3f 25 3f 00 37 25 3f 00 24 00 64
00001f0 00 08 14 22 00 14 14 14 00 22 14 08 00 02 29 05
0000200 02 00 1e 21 2d 0e 00 3c 0a 09 3f 00 3f 25 26 18
0000210 00 1f 21 21 12 00 3f 21 22 3c 00 3f 25 25 20 00
0000220 3f 05 05 01 00 1e 21 29 19 00 3f 04 04 3f 00 3f

If we look at the first few lines, we can see that the characters are between 2 and 6 pixels wide.
Let's try to have a look at the start of the alphabet. In the ASCII table, we can see the value of the letter A is 65, and since values start at 0, that means this is the 66th character. So first we will compute the sum of the widths of the first 65 letters.
That would be 4 + 6 + 6 + 6 + ... + 4 + 4 + 4 + 5 = 263
So if we skip the first 256 bytes (the character widths) and then the next 263 bytes, we should get the data for letter A. So let's look at the data that starts at address 256 + 263 = 519 (207 in hexadecimal).
I have highlighted in red above the width for the 66th characters, which as we can see is 5, and the 5 bytes starting at address 0x207.
Let's write them, with the corresponding binary representation below (with the least significant bit at the top):
 3c 0a 09 3f 00
 0  0  1  1  0
 0  1  0  1  0
 1  0  0  1  0
 1  1  1  1  0
 1  0  0  1  0
 1  0  0  1  0
 0  0  0  0  0
 0  0  0  0  0

So now a bit of ASCII art: we replace the 1 by a @ and the 0 by a space

     @ @
   @   @
 @     @
 @ @ @ @
 @     @
 @     @

You recognize something?

Just for fun, let's do the same for the next two letters:

 @ @       @ @ @  
 @   @     @     @
 @ @ @     @      
 @     @   @      
 @     @   @     @
 @ @ @       @ @

So we can edit the font file using an hexadecimal editor for example. This involves some ASCII art (exciting :-), and it can be challenging to fit an accentuated characters on 5x8 pixels), some additions on hexadecimal numbers and some conversions between binary and hexadecimal (boring :-( ).

This concludes my three parts posts on translating games for ScummVM. I hope you found it interesting. Now I will take some rest while you start testing Sfinx. There is one last thing though: ScummVM is a community effort, and it does not only involves software developments. You can contribute in other ways, such as translating freeware games, translating ScummVM itself or helping with the user manual. So if you are motivated to help us, please get in touch for example on our IRC channel (#scummvm on irc.freenode.net) or forum.


by Thierry Crozat (noreply@blogger.com) at September 18, 2014 09:23 PM

 

curved edge   curved edge