Month: July 2025

This week I continued to work on MacVenture engine. I managed to fix a few blocking bugs and complete to the end Déjà Vu, Uninvited and Shadowgate. I also improved text input dialogs, made exit buttons clickable (as a shortcut to “Go” and “Open” commands), fixed the bug where titles are not displayed at saves. There are still a few things that needs to be implemented: diploma window, clean/mess up functionality and to fix how certain item bitmaps are displayed.

The first Déjà Vu went fairly well, and at the start of the week I managed to get through the end of it. After that, I went with playtesting Uninvited, and this is were I encountered the first problem. To progress further in the game, I needed to go through the door, but two deadly dogs were in front of it, blocking the path.

To pass them, you need use the “Speak” action to say the magic words and thus use the spell. The magic words are: “Instantum Illuminaris Abraxas”. I typed the words, however, that did not help and I died:

I tried over and over, with lowercase variants, checked if I needed some other item in inventory, however, everything was right according to walkthrough guides. This is when I started checking the scripts, as clearly, something wasn’t triggering. Luckily, there are only three opcodes involving strings: ScriptEngine::opadEQS, ScriptEngine::opaeCONT and ScriptEngine::opafCONTW. The one responsible for the situation is opafCONTW, which checks for the containing word. So I looked up, I discovered it was checking for the lowercase variant of the magic word: “instantum illuminaris abraxas”. So, fortunately, this turned out to be one line fix. Interestingly, when I debugged and printed out the strings from that method, as I discovered the game (apparently all games made with the engine) was containing a very huge variety of curse words. I won’t write them down here, but it has every word you can think of 🤪.

At the same time, I changed the way input text dialog worked. Before the changes, it was essentially an ordinary dialog, with no cursor of the text, and contained the same hardcoded title for all dialogs – “What would you like to say?”. This was also easy to fix, as the I essentially copied the code for cursor from MacTextWindow, and I added a line to fetch the text from the object, not from the hardcoded global table. The end result looks like this:

Another feature I finished was pressing on the exit buttons to go between the rooms. This is optional feature, as you could use “Open” command to open the doors and “Go” to actually go through the door. However, when playing the games this quality of life feature really comes handy, and was worthwhile implementing. Especially, when the code was all there, and I just had to copy it from Webventure repository.

After finishing Uninvited to the end, I went with playtesting Shadowgate. This game took a little longer, as there is a slightly annoying game mechanic with disposable torches, which are needed to be managed. There was one little blocking element, when reaching the room with the sphynx. Essentially, you have to solve the riddle of the sphynx by giving him the right item. However, when I operated the item on it, the game kept crashing. After looking for the cause a bit, I figured that the reason was dead simple: the engine had two versions of focusObjWin(ObjID objID) function. The safe version focusObjectWindow(ObjID objID) that checked if objID really referred to existing window, and unsafe that did not have this check. And of the course, when the code related to sphynx was executed, the unsafe version was run. The fix was just get rid of the unsafe version.

Lastly, I made sure the main game window and inventory windows kept their titles preserved when loading a save file. This took a bit of rewiring and adding for methods, as the code for managing the windows we have now is a little different from the original sources. In the original, main game window and all inventory windows where closing and opening at the start of the game, winning, losing, and save loading. I added back things for the inventory window, however kept the main game window unchanged for the most part. I make a workaround fix to set it’s objID to zero, so that when script executes, it updates the window info. The reason was that a decent portion of code needed to altered to adhere to the change, but since that one line fixes the issue I decided to leave it as is.

Last I week I started working on the MacVenture engine. The engine is based on the javascript implementation. It is very close to completion, what’s left is to fix a few leftover bugs and playtest the games, so that they are completable. I started with the first Déjà Vu game and close button was not working, drag (lasso) selection is missing, and in certain places the game window was not displaying the correct images. Throughout the week I tackled these problems.

As said above, first thing I noticed is that the close button was not responding, e.g. after clicking on it, nothing was happening. It took quite some time to figure out what was going wrong, but eventually I found the reason for it. The problem was that the code for identifying whether the mouse was inside close button was looking like this:

bool MacWindow::isInCloseButton(int x, int y) const {
    int bLeft = kBorderWidth;
    int bTop = kBorderWidth;
    if (_macBorder.hasOffsets()) {
       bLeft = _macBorder.getOffset().left;
       bTop = _macBorder.getOffset().top;
    }
    return (x >= _innerDims.left - bLeft && x < _innerDims.left && y >= _innerDims.top - bTop && y < _innerDims.top);
}

As can be seen, it returns true if mouse position is at the corners of window borders. And it works correctly if close button is indeed at one of the corners, as in WAGE games:

However, here the close button has a little offset to right and bottom from the left top position of border:

So to make it work, I added offset fields for the closeButton, and made  MacWindow::isInCloseButton() method to look at those offsets, if they are present.

Next problem was absence of drag (or lasso) selection. It is needed to select multiple items in the inventory at once, as can be seen here:

However, making it works wasn’t that easy and took me a couple of tries and rewrites, and to the moment of writing, there is a slight bug that needs to be fixed. But the idea is simple: on the mouse button down event save the pivot point of the selection, on the mouse move event update the the second point, and lastly, on mouse up event create a rectangle from the two points, look if any inventory objects are inside and mark them as selected. The difficulties was there because of the code flow structure which was altered and become noticebly different from the original code.

What really helped me here and in the later problem is that I managed to get original code running and made it debuggable in browser. I updated the jQuery version the fresh one, fixed a few type errors and imported the main game code as module, so that when it is compiled with closure compiler, the separate mac.js is generated.

With this, I stepped through the js code, looked how the lasso was done, and made it essentially working:

 

Afterwards I worked on fixing the issue right at the start of the game. What happened is that, when examining the mirror object, the engine would not pause and quickly skip the image of character. It happened, because the engine was not pausing after MacVentureEngine::clickToContinue() function was called. I added an additional flag that is set when clickToContinue is true, so that the game pauses, and the main game window shows the correct images. This is how it worked before and after the fix:

There are two more bugs left from the last week which I am fixing now. First one related to window resize – when making the window smaller, it stops showing borders:

The second also probably related to it. Clicking at the resize button selects the object if that object happens to be there.

For this week, I plan to continue the work on the MacVenture and fix the above mentioned bugs. Afterwards, I will solely focus on playtesting.

Lastly, I want to mention that I succesfully passed the Midterm evaluation for GSoC. I want to thank my mentor – Eugene. He has been very supportive and always there for help and explanations. Also, the tasks and engines were all diverse and very interesting to work on. I am very enjoying contributing to ScummVM.

Last week I continued to work on TeenAgent, in particular implementing the support for voiceovers. I first wasn’t sure about that since I could not find anything related to voicing in the sources we had. However, because the engine can load the voices and play them, I decided to map the voice indices to each text and play the voices in the same places where Text-To-Speech’s sayText() are called. Apart from this, there was a bug report for the qdEngine game, so I quickly returned to it to add support for punycode.

The idea for implementing the voiceovers is as I said to map the voice indices (1..2043) to each text. I played with the sounds to see how the voice resources are located and figure out the ranges. For the most part, it was sequential. The ranges are as follows:

• 1 – 333 Messages
• 334 – 566 Scene objects descriptions
• 567 – 591 Combination messages
• 592 – 683 Item descriptions
• 902 – 2040 Dialogs

Interestingly the range [684 – 901] between Items and Dialogs is empty. Implementing the first four items were relatively easy. For the display message methods I just added an additional argument for voice ids, for others I extracted that from the newly added method – getVoiceIndex(). However, the dialogs were hardest to get right. At the moment of writing, I am still working on it, most of them are working, but still some parts are wrong. The main problem I discovered is that the voice resources for dialogs are not really ordered, not every dialog line is voiced and some voice resources are empty. For the empty voices, I discovered that checking the size, i.e, if its too small is enough. That is, all of those voice resources are 4 bytes in size and I got the list of them and implemented isVoiceIndexEmpty() helper method. But the fact that some voices are not ordered, really became an issue and I had to manually find, listen and check every problematic dialog/lines. Because of this, the method for computing voice indices became a mess, and I had to rewrite it over and over.

Despite the difficulties presented above, I am close to finishing it, and once the dialogs are done, all text in the game will have a voiceover. Good thing is that I have every line of text extracted from the previous weeks, so even if I don’t know Polish, I still can with relatively no problem find the the exact text from the voices I hear.

For this week, I first plan to finish this task (today) and then move to working on the next engine – MacVenture.

This week I continued to work on adding Russian, Polish and Czech strings. Last week was spent with extracting those strings from the executables, and this time I worked on making the engine load them. The task was a bit challenging and it took a lot of trials and errors the get certain things right. Let’s break down everything I did.

First of all, I had to think how I would store and then load the language specific data. Initially I thought maybe I could fit the data into in their respective locations in the original .dat file, but when looking at Polish and Czech executables, which are much larger, I realized that would not work. So I ended with adding all the strings at the end of original .dat file. In the engine, I added Segment object for each of the items, and made the engine to read from them instead of the data segment.

I started with loading and displaying Credits and Item names, as these two were the easiest. For the loading part, I introduced two Segment objects containing these two resources and made them read the data from .dat file:

I also added Resources::precomputeCreditsOffets() and Resources::precomputeItemOffset() to precompute offsets after the loading is done. This is identical to how dialog offsets are computed and is needed so that the engine can get to correct location where credit/item data start when it asks for a particular credit/item number.

Next, I added message strings. Adding them was also quite easy, and took the same approach as the one above. The only thing that needed to be carefully taken care of was combine error message. In the .exe they don’t come together with the rest of the messages. In fact this message is the last part of the combining table section. However, for the consistency, I placed this message as the last item in messages segment.

Speaking of combination messages, I added them after this. Each combination consists of the following members:

struct {

   byte _obj1Id;

   byte _obj2Id;

   byte _newObjId;

   Common::String _combinationString;

}

I split this structure to two: one containing the first three bytes which are the same for all languages, and the one containing just the combination strings.

After that, I worked on dialogs. Initially I thought it would be the same as with other strings, but at the time I forgot about dialog stacks. Because of this, the dialogs for English and Russian versions were fine, but some dialogs in Polish and Czech versions were completely off the context. Turned out, that some dialogs should be popped from dialog stacks and shown only when certain events are triggered. They were working for English and Russian versions, as the code for reading the dialog stack data was still reading it from data segment, not from the segment that was dedicated to it. After realizing this, I added stack dialog stacks as a resource to .dat, added code for loading it and correct dialogs started popping out.

Lastly, I worked on adding scene object names and descriptions. This part was the trickiest. First of all, I realized during extraction, I made an error, and didn’t not consider cases with items with default description. That is, after the null byte, these items contain 01 byte, which indicated that the objects will be given the default description name – “Cool.” (English), “Miodzio.” (Polish), “Bezva.” (Czech), “Вещь.” (Russian). Once I realized this, I fixed it here.

Another important thing to point out is that this kind structure is a part of savefile, and the objects and their members (including names) are modified in runtime. The last part about the names is crucial, as certain objects, namely four – “girl”, “robot”, “boy”, “bowl” are modified changed to their “real” names – “Anne”, “Mike”,  “Sonny or whatever”, “body”. I implemented the support for this, but forgot crucial thing – I didn’t set enough space for the initial names, so that when they are changed, it does not overwrite description part. Because of this, I was getting constant crashes when trying to load the older saves (before changes in the pr). After finding about this, I was able to fix the issue and thus, preserve compatibility with old saves.