D2K at 17 Feb 1995

Just a quick report on this week's activities - I have just received the forms which will get me my visa, allowing me to live and work here in California for a few years, and I have to nip back to Blighty tomorrow to complete the formalities at the American embassy in London. I'll be gone about a week, and I'll doubtless avail myself of the opportunity to have a vindaloo and a few pints of llager, hang out with my UK mates, drink proper beer, experience proper English February weather (i.e. cold and icy), and most importantly collect my ski gear! It'll be a relief to finally get my visa, so I can stop being just a visitor, and do important stuff like buy that Mazda MX-5 and get the hell out of this apartment and into somewhere with beastie-support capability. I notice that the documentation says that I will officially become an Alien Worker. I hope that doesn't mean I'll have to be forever looking over my shoulder watching out for Ripley...

The game's going *fine*. I am most pleased with Plus. Started the week by adding in an AI droid, which hovers near your ship 'till it 'sees' an enemy, then swoops in and lasers it up. I lliked it so much, and as it's just another generic object and easy to have other iterations of, I decided to give you a pair of these little beauties, one each side of the ship. They're great. They're fast and smart and you can really kick some severe botty with them at your side. Then, as they were so cool, I decided to make them even smarter, and have them catch falling Humanoids as well, and bring them back to your ship. This proved to be totally cool. It's just great to be in the thick of things, bad guys everywhere, robopterodactyls disgorging streams of bouncing, tail-twitching goats, Llightning Llaser blazing, and see your droids flash off, execute a couple of flawless rescues, and bring you the booty.

Then, since the droids were so effective, I decided to crank up the enemy density on Plus. You get twice as many Llanders per rez-in, and twice as many on any given wave. This makes the higher levels *unbelievably* busy, but you've got the droids at your side, and your rapidfire laser's a-pumping, and you can *handle it*. Everything's just screaming by, big explosions all over the place, shreds of enemies everywhere, and it keeps 60Hz. Yum, yum, yum. I've been playing with the first demo tune sent to us by Imagitec playing back on the PC's speakers, volume on high, got up to level 30 odd, with 700,000 points - and I'm starting to get that intense, buzzing speed-rush that I love in a game... mighty fine. Got some new artworx from my artist today, but I probably won't get a chance to put them in until I get back from the Old Country ... after they're in, I'm gonna pull back off Plus, 'coz it's 90 percent there now, and get into the let's-torture-the-object-processor stuff which will let me determine how much funky stuff I can throw into the backgrounds on 2K. Then I can give my graphic artist specs on the BG generator and have him get *really* busy....

It's llooking more and more like this is gonna be on CD, so you can llook forward to totally awesome music, no limitations as we'll be doing direct redbook audio. Also we can have a shitload of levels, and I'd kinda like to do a historical section on there as well, as we get so much room; an interview with Eugene Jarvis, maybe, and other historical data about Defender.

Anyway, that's it for now... right, I'm gonna have four masala pappadoms, a nan, and a chicken vindaloo with pilau rice, not to mention a couple of pints of llager... I'm salivating already.

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(:-) - playing T2K on my llaptop on the flight, no doubt...
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D2K at 12 Feb 1995

Finished off my warp sequence on Monday, then decided that I needed some momentary screens to flash up at entry and exit to warp. Doing this, I got struck by the Bug from Hell. You get one of these from time to time. My new circledraw, which is a pretty simple thing and had been working perfectly, started going bananas. At first I thought this might be the infamous A1 clipping bug manifesting itself again, and indeed after I inserted some voodoo to ward it off the problem seemed to go away. Then, upon adding a satisfying noise on exit from warp, once again the blitter began to emulate multiple curved yellow fruit. Hmm... problem appeared to be dependent on the position of code... something somewhere must be treading on RAM...

Eventually after an extensive debuggery session I found that in part of a GPU module I wrote at the start of November, if a certain value was $ffc8, it would fritz my circledraw. Closer inspection revealed that I had typed 'r23' instead of 'r24' on one line of the code, so a byte was getting written to wherever r23 was pointing at, which could be anywhere... fixed the typo, all was funky.

Removed the Lissajous explosions and reinstated pixelshatter. Much happier, the explosion density is back up there. Since the sprites are truecolour and the explosion-plane is 256 colour, there is a slight downgrade of the colour resolution of a shattering image, as it's translated to an approximation in the 256-colour plane; you won't care, as all the pixels are receding from each other very quickly anyway.

Even so, *still* dropping out of 60Hz when you've a shitload of swarmers onscreen and plying the Llightning Llaser. Tried various optimisations, got some stuff back, but still you'd get the framedrop. Noticed that the framedrop always occurred around the biggest mountains, due to the blitter sucking bandwidth to draw the wibbly textures... so: simple solution, reduce the mountain height in Plus. 60Hz all the way. Goody.

Put in the Llightning Llaser gauge - no longer unlimited. Extra charge is added when you get an extra life and Smart Bomb.

Then, put in a new enemy you're going to hate. I call it the Phish, it looks like a kind of robot pterodactyl that flicks a tail like a fish. It flies towards you as soon as it 'sees' you, and takes multiple shots to kill. This makes it a pain on your Llightning Llaser - it drains multiple charges, and holds the laser for a long time - for example, if you come out the Star Gate with LL activated, expecting to pop a Llander and tractor up the Humanoid, if there's a Phish on the screen your llaser gets locked onto it for long enough that you miss the Llander and it's byebye Humanoid, hello Mutant.

Phish fire bursts of conventional bullets whenever you shoot them. They also emit, when they're on the same screen as you, a stream of tiny goats - yeah, I know, Atari will probably want me to change the graphics - which bounce about leaping off the mountainsides. These are a menace. It's all too easy to catch a goat upside your ship while you're busy trying to catch a Humanoid.

Finally last week, I decided that I wanted a neat effect when you Smart Bomb, so I produced this big circular explosion which expands over the screen when you do so. It looked so neat, that I thought it might look good if applied to the Llightning Llaser too, and by God it does! When you cut loose in the middle of Swarmers it's like multiple flashbulbs going off all over the screen. And still inside the 60Hz. Yummy, yummy.

Next up - I have a small bug I need to fix, then maybe some AI assist to help you deal with everything..

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(:-)
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D2K at 04 Feb 1995

Classic Mode is pretty much finished, bar a bit of tweaking. It's basically identical to original Defender, uses the same sound effects sampled out of the coin-op; the main differences being that it keeps 60 frames throughout, and doesn't 'disappear' enemies due to the draw loop getting overloaded - we've got a bit more horsepower (llamapower?) than the original arcade game had, so the draw loop never gets overloaded. There's a bit of tidying up to do - like the humanoid-fall noise sometimes doesn't cut off when you catch a falling Humanoid - but that'll get taken care of next time I do a spit-and-polish pass. At the moment I am concentrating on getting Plus defined.

Plus is getting there. The idea of Plus is to keep the essence of classic Defender, but re-do it with more detailed graphics, one or two extra weapons, and some new bad guys. I've incorporated the Star Gate out of the game of the same name as well. The Plus control mode is also the same as it will be in 2K - if anyone has played Llamazap you already know it. It allows you to fly your ship backwards at times - basically you can apply 'retro thrust', which gives you more control over speed so you pile into enemies less often, and means you can even back away from an enemy while still firing at him - useful if you are attacking a shielded enemy.

Your first new weapon is the Llightning Llaser. You can think of this as being a bit like the Superzapper out of Tempest, attached to your Defender ship. When you hold down the LL button, lightning strikes out from your ship and hits enemies one at a time, at a stroke rate which will probably be able to be adjusted by powerups. Cutting it loose in the middle of a crowd of Swarmers is pretty spectacular.

The LL has a special function if used to attack a Lander that's carrying a Humanoid. It llocks onto the descending Humanoid freed up when you kill the Lander, and acts like a tractor beam, dragging him towards your ship. This makes it easier to gather a lot of Humanoids under your ship, which is something that'll do you good in the gameplay for both Plus and 2K.

Graphically, all the classic Defender enemies have been redrawn as animated true colour objects. The little Humanoids are particularly cool - they run about in a nicely animated way and wave their arms in distress when they're being hassled by the Landers. The mountains have been filled in, with a dynamic plasma texture, which wibbles up and down as you fly along and also colour-cycles. I call it the Llava Llamp texture, and the folx at Atari really like it. I'll make this texture change each level to provide variety.

I'm pleased with another touch to do with the mountains that I put in last week. It's out of the Melt-O-Vision bag of tricks, and produces, down behind the mountains, these kinda flames which flicker and dance as you move around. Kinda like pale fire, or an aurora, or the soft rippling fur of a llama clad in rainbows. It's pushing me right to the edge of my 60Hz FUR, but I'm determined to keep it, as it looks so cool.

It llooks like the Lissajous particle explosions may have to go, as they're pushing me out of 60Hz when you have a bunch of stuff on screen. I'll probably go for some version of pixelshatter instead that I can get the Blitter to do instead of tying up my GPU.

Also, llast week the first Easter Egg went in...

At the end of last week I was working on the level warp - like in arcade Stargate, if you jump in the Stargate with four or more Humanoids you can skip levels. I had put in this kinda particle tube effect, made out of the same routine for the Lissajous explosions, but although it looked interesting I thought it wasn't really in your face enough. So, I wrote this thing which does a tube made up of circles of colour, and by scrolling the palette you get a nice rushing-down-a-tube kinda thang. Then I stretched out the pale fire so it goes all the way up the screen, so you can see the flames outside of the tube. I think I'd like to use Object Processor interrupts on the GPU now to warp the overlay with the tube drawn on it, so that the whole thing kinda shimmies around, I think that'll look cool. That's what I'll do first thing next session. Then I'll get busy with the new pixelshatter explosions.

While I was doing that tube I made this nice fast circle draw - god bless Mr. Bresenham! - which I'm sure will be useful for something else as well. We'll see what happens.

Llater...

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(:-)
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