It feels good to have finished the almost two year long work on it, but this does not mean that I’ll leave it. Nor have I completely given up on making another game with it. We’ll see what happens.

I got a lot done on the SLUDGE adventure game engine during the summer. (If you’re interested in knowing more about that, and maybe trying it out, you should head on over to the Adventure Developers forum. That’s where the SLUDGE action is.)

Now my SLUDGE-making speed has slowed down a bit, for two reasons. One is that the vacation is over, and my paid work naturally has priority over this stuff. The other is that I’ve been spending a little time [i]using[/i] the SLUDGE development kit, making Frasse and the Peas of Kejick: Special Edition. No estimated release date for that yet, but I’m hoping to get it done this side of Christmas.

Since my last progress update, I’ve been busy. First with work: End of the semester and such. Not much time for anything else. After that, I went to the south of Sweden for a week to play and learn more about Jazz and World Music. (Yes, that’s me in the picture with a cornet in hand, trying some livelooping.) Great fun, and inspiring. (Some sound clips from the course are also available at the site I linked to, in case you’re curious. It’s me trying an improvised cornet solo in the middle of the Arabian 7/8, and playing the bassoon in the Tango.)

But now I onec again have time for a bit of programming, and am making progress. I’ve been reading the Cocoa programming book by Aaron Hillegass that I mentioned in an earlier post. It’s really good, and I understand why it’s recommended as “the book” to read for people who want to learn Mac programming. As a result, I’m starting to grasp how Mac programming works, and I’ve added an options window for Sludge. I also find Mac GUI programming so enjoyable that the thought of porting the development kit too, and not just the engine, is looking more and more appealing. The idea of maintaining the Windows port is at the same time becoming less appealing, so I’m hoping that someone else will show interest in that department, but if that doesn’t happen I won’t let the Windows port fall behind (much) either.

I’m still waiting for Tim Furnish to add me as a developer at Sludge’s SourceForge site (he said that he would, when he found his password), so that I’ll be able to upload the things I’ve done with the engine.

I may also become sidetracked one weekend. I visited a site related to Allegro (the game development library I used to make Rocket Duel), and learned that there’ll be a new speedhack coming soon. Speedhack is an Allegro programming competition run over three days (starting July 10th), and I’ve registered intent to participate. It might be fun. (The rules aren’t completely known until it has started, but I’m hoping that it’ll be fun, and a bit challenging.)

• Collision detection. (I.e. checking if the mouse is over a character.)
• Thumbnails for saved games.
• File rename/delete.
• Parallax layers are pasted properly when doing a freeze.
• getPixelColour (untested, but should work)
• The snapshot-related functions and special effects.

This means that all Sludge games should be playable! There are still things remaining, but everything is going in the right direction. (Beta testers – the updated engine is available at the same location as before.)

I have also ordered two books that should help me learn some things I should know: Cocoa Programming for Mac OS X  (I’m told this is the must-have book for Cocoa programmers) and OpenGL Shading Language.

Lighting works. It was easier to add than I expected. (multitexturing with OpenGL is quite straightforward!) This is an area where the 32 bit graphics (instead of the 16 bit used by Sludge v 1) make things look better. Out of Order in particular looks quite impressive. Tim Furnish did some cool things with the lighting that looks great now that it’s a bit more subtle.

I have also discovered and fixed some bugs.

Now that most systems are functional, I’ve started testing a bit more. I’m now testing all Sludge games I have access to: (I want to make sure that I don’t break anything.)

• Out of Order
• Frasse and the Peas of Kejick
• Nathan’s Second Chance
• The Game that takes Place on a Cruise Ship (and its demo The Interview)
• Cubert Badbone
• Mandy Christmas Adventure
• The sample games, and some small test games I have made.
• (Erwin Broekhuis has also tested it with his work-in-progress.)

Besides these, there are two more Sludge games that I know of that have been released: The Otto Experiment demo and Kats. Both of those have disappeared from the web. If you know where I can find them (Otto in particular) or another game that I have forgot about, please let me know.

Mandy managed to crash the engine when I started it. It turned out that the reason for that was that it’s in Slovak. (Translations are available, but I ran it with the defaults first.) Slovak uses a lot of accents, and those letters are encoded in the Windows text format in the game file, so when the game tried to set the title of the Window, it failed spectacularly. I now convert the title to Unicode, so it works. (Internally, Sludge uses its own text format, so that was never a problem.)

Remaining things to do include:

• Thumbnails for saved games.
• Pixel perfect (or at least close to it) collision detection. (Neither Frasse nor TGTTPOACS can be finished without it.)
• File renaming/deletion (useful for dealing with saved games).
• Pasting parallax layers when freezing.
• getPixelColour
• Some special effects.
• Improve placement of images. Since OpenGL doesn’t care about pixels, images sometimes get placed a pixel or two off. I improved the situation a bit yesterday (by adding 0.325 here and there), but small visual artefacts still turns up in a few places.
• Startup window, for selecting language, window resolution, full screen or not…

There is also launch, launchWith, registryGetString and the functions for movie playing. These are low priority for me. I suppose I won’t get away with removing the launch functions (people have used these, and I guess they might be useful), but I think registry reading should go. (There’s no registry on Mac and what’s the use for the function anyway? there is no function for writing to the registry. Has it been used?) Movie playing, if done at all, should change. I’ve never used those functions, but I recall people having codec problems. “Whatever AVIs Windows can play” is asking for trouble. It needs a defined set of formats.  I’m thinking Ogg Theora, or letting this mostly unused (has it been used at all?) function go.

Here’s what I’ve done since the last update: 

• Saving and loading now works. (No snapshots yet, though.)
• The engine is now resolution independent, and scales everything nicely. It also keeps the aspect ratio constant. (I still have a few checks to add to make downscaling safe.) I experimented a bit with a resizable window, but that was a bit too messy. I’ve read it might be better handled in SDL 1.3, though, so maybe it the future…
• Cocoa integration. Now command+Q works properly, and errors pop up in nice cocoa alert panels. (Game selection is also done through cocoa, unless there is gamedata in the app package.)
• Found and squashed two bugs. 

Now there are no known bugs left, but there are still unimplemented features that to the uninitiated may look like bugs. There are 24 TODOs left in the code. Biggest TODO is the lighting, which I still haven’t touched.

The z-buffer now (almost) works! All my tests work great except the Interview. I suspect it may be due to the high number of layers used there, but I don’t know. (If I had known, the bug would have been fixed already.)

Edit: Now I know, and now it’s fixed!

I’ve also fixed the bug that was keeping some music silent, so all sound should now work properly.

This means that the following small test programs work as they should (unless I’ve missed something):

• Scrolling Credits
• Small Example
• Bouncing Object Demo

These programs are also part of my test suite, but still have some issues:

• Parallax Scrolling Demo (I haven’t implemented parallax scrolling at all yet)
• Verb Coin Demo (Only Z-buffer and lighting left to do. Oh, and the darkBackground function used when bringing up the inventory. I think that’s all.)
• The Interview (Z-buffer, Save/load, darkBackground)
• Cross-Fade Demo (Music won’t play. Odd since sound in general works. Even the music in the VC Demo, which is in the same format, so I think it’s the fading routines that has the problem. Will have to investigate some more.)
• “Mathias”, my unfinished game that I was working on before I started on Frasse. (Z-buffer and Save/load.)
• Frasse (Most things work, but Frasse uses most of the functionality available in Sludge, so basically everything will have to work before Frasse runs properly.)

Those are all the programs I have been testing. As you can see, things are looking good! The remaining big issues are: Z-buffer, lighting, save/load and music. The HOTSPOT lighting mode will be easy (I’ll simply use the same technique that works fine for colouring the text). PERPIXEL will be more complicated (i.e. I currently don’t have a clue how to implement it). The music thing requires investigation. Save/load shouldn’t be a big problem (I hope), but I’ll probably have to write platform specific code. The Z-buffer… well, that’s another area where I don’t really know how to do it. (But that was true for most things when I started this project, so I’m still optimistic.)

A search for “TODO” in the source return 30 occurrences. There is still work to be done. Besides the things I have already mentioned, TODOs are in: Snapshots, Background Effects, getPixelColour (has that function ever been used, I wonder? if so, for what?), launch (if we add a setup screen like other engines have, do we really need this one?), registryGetString (this one is going to disappear – the registry only exists in Windows, and since we’ve never been able to write to the registry, I don’t see much use for it anyway), showFloor, showBoxes, pixel perfect collision detection, proper error messages (right now, I simply print to stderr), burnString (right now, it duplicates pasteString). That’s it. Now you know how far along this is. (Or you should at least have some idea, if you’re familiar with Sludge. If you’re not, everything after the break was probably useless information to you.)

Btw, I have – like most Mac software – interpreted Ctrl+click as right-clicking. This is done automatically in the engine. The game doesn’t know, or care. It just works.

But you can rest assured that I will return to both Sludge and Frasse. Neither is abandoned. Maybe I’ll get some things done tomorrow…

Happy Easter!