Frotz work in ScummGlk is ongoing

Work on the ScummGlk engine is ongoing. Since Christmas holidays I've been primarily focusing on adding support for the version 6 graphical Infocom games to the Frotz sub-engine, with particular focus on Zork Zero to begin with. Whilst I don't count the version 6 games among the best of the original Infocom line-up, ScummVM has always been about providing as good a coverage of old games as possible. So from my point of view it's worth spending the extra time adding support for the remaining Infocom games now rather than later, and only moving onto the next sub-engine once that's done.

Below is a screenshot of Zork Zero as of when I came back on the 7th January:

As you can see from the screenshot, the background is starting to be properly rendered, and the 'A' and location glyphs are properly rendered and interleaved with the text. The status bar still needs some work, though.. although it is being rendered, it's then being completely wiped out by the status bar window, which isn't even displaying any text yet.

Right now, I'm focusing on adding the 8x8 fixed size font used in the original games. If you look closely at the screenshot above, the current resizable TrueType font doesn't really look crisp at that low a resolution, and is somewhat blurry. I'm currently making a tool to use the same font data that Frotz has, and produce bitmaps to add to the fonts Zip file for the different 8x8 font styles (normal, bold, emphasized, and bold & emphasized). It has had it's share of issues:

 Somehow, I don't think I've got it quite right yet.. :)

Anyway, progress is gradually being made, and I hope to have Zork Zero fully supported soon. The other v6 games currently error out immediately during startup, but I'm hoping further adding support for them will be a simpler matter.

It's time for a very verbose change of pace

One of the things I like about my work on ScummVM is that it's a hobby rather than a profession, which gives me the freedom to switch what I'm working on when I desire. I've previously had encouragement to resurrect my Gargoyle engine work from about a decade ago. It was an early attempt to add support for Frotz into ScummVM, and at the time it was rejected due to multiple reasons. It was specific only for Infocom/zcode games, lacked clipboard, truetype fonts, and Unicode support. Most of these things have since been solved by the ScummVM framework itself, which now supports all of them. So I thought, why the heck not, and decided to work on it again.

However, my original Gargoyle engine being limited to just Zcode was a problem. Not only wasn't it extensible to other IF systems, but it would also take work to properly reimplement it to support Unicode. In the end, it was just simpler to scrap it all, and start from scratch. Luckily, there's the very convenient Glk specification, that was specifically created for easing porting the various Interactive Fiction interpreters to other systems. I knew that by supporting it, it would make it easier to create a framework that could support multiple different interpreters as sub-engines.

So I created a new Gargoyle engine, which I've since renamed it to ScummGlk to avoid ambiguity with the stand-alone Gargoyle project which also implements the Glk specification. After over a month of work, I've created an engine that implements the bulk of the API, and implements two sub-engines under it so far.. Scott for Scott Adams games, and Frotz for playing Z-Code/Infocom games. Scott was useful as a test case, due to it's simplicity. With it as the first sub-engine, I was able to focus on getting the ScummGlk core working. Then Frotz was a fairly obvious second choice, given it's popularity and large number of available fan games.

As of last weekend, the review period was completed for the engine, and it was merged into master. Daily builds now include support for both sub-engines. I've spend the last week fleshing out detection entries for all the ZCode games on the if-archive, so all the games will be automatically detected by the launcher. I'm going to wait on announcing an official testing period until I finish support in Frotz for V6 games. But if you can't wait, you're certainly welcome to jump the gun and try playing some games. Maybe one of the early Zork from GOG, or the immortal classic Freefall :)

Having the engine included into master will be a real nostalgia trip for me. Even prior to my original Gargoyle module, and before I even started working on implementing adventures in ScummVM, I spent several years as part of the Interactive Fiction community. Indeed, the Hitchhiker's Guide to the Galaxy was one of the first computer games I ever had. I spent way too many hours getting frustrated with the game's puzzles.