In the first week, I started with finishing the work on qdEngine, then began working on the SLUDGE engine.
With qdEngine, what needed to be done was to improve the performance in the game Dog-n-cat: In the Footsteps of Unprecedented Beasts. After a little investigation, it turned out that whenever the tiled animations were drawn, the uncompress() method was called. This was very costly, and the solution was to cache the already uncompressed animations.
After finishing with this task, I was assigned to finish the SLUDGE engine. The engine is almost finished, with only a couple of small things to be done. I began with implementing the support for extended saves, which turned out to be a little harder than I expected. In particular, there was a problem with the saving the files in the ScummVM format. The saves with simple names are in this format: %s.%03d, where d is slot number. At first, I didn’t know how to get the slot number from the name of a save. This was needed for loading the save files in the games. The problem was that the SLUDGE game interpreter is based on stack machine and the only thing which is pushed to stack when loadGame function is called is the name (description) of the save.
This problem took quite a while to solve, but after many unsuccessful attempts and tries, I finally came up with the solution. I realized that almost every game when loading/saving the game shows the save file list:
This meant that I could create a lookup table that maps the save name to slot number of the save file and use it for saving/loading procedures. And indeed, it worked out.
There was also a little interesting task was to testing transition modes of the engine. For that, I needed to create a demo with SLUDGE development kit, run it on original interpreter and on ScummVM, compare, and see if they are different. The transition modes appeared to be the same, so there was no additional work needed from my side.
After that, I quickly implemented return-to-launcher feature, fixed a bug in thumbnail loading and wrote a code to simulate the right click of a mouse. Lastly, I made it so message box with a specific message set by a game pops up when exiting the game:
