Friday night musings

I found a few spare minutes tonight to work on fixing the AI; managed to find the graphical glitch (took about 20s) and another 4 sections of code that had bugs. Much to my dismay, the guards still run in the wrong direction on the first demo level.

For those interested, the debugging process atm consists of opening both the Apple II and Coco 3 versions in the MESS emulator side-by-side, and running them (manually) in lock-step, comparing key results throughout the AI routines. Painful but a no-brainer! And it's actually fortunate in this instance that the very first guard starts off in the wrong direction - it should mean that the first pass through the AI logic will reveal most of the bugs! I mean, I've found 4 bugs already and I've only stepped through about a quarter of the AI logic!

It might seem to some that there are an awful lots of bugs in the AI code (I'm looking at you James) but you need to remember that I've added over 700 lines of 6809 without much visible feedback along the way. When porting the mechanics of movement, I was able to code small chunks of routines and - usually - immediately see whether or not it actually worked. And then fix the bugs before blogging about them!

I've also been thinking a bit about the colour version. I'm pretty sure that with clever use of the palette I'll be able to render both colour and monochrome versions of the Apple II display in the Coco3's 4-colour mode using the same graphics data. This of course means there's no reason to retain the 2-colour version of the game... though being the pack-rat that I am, it'll probably remain in the source only .ifdef'd out.

And that also goes for the Neo Geo version, of course. On that note, I've decided to tackle an automated static translation of the original 6502 code - it should be an interesting exercise in itself! I guess once I've got a 68K source base, I could also look at porting to other platforms such as Amiga, Atari ST and some other more obscure platforms.

But for now, back to debugging...