There's a new release of Thunder&Lightning in preparation. It will feature some MFD enhancements like a missile camera and a target view. Much improvement has been made with regard to AI performance. It is basically all there, I just need to get it all commited to darcs in a sane way (having my notebook bricked didn't help either...)

So, lacking some real news, I thought I'd provide a little bit of background. Thunder&Lightning is inspired by (but not a remake or clone of) a classic home computer game called Carrier Command by Realtime Games. If you haven't heard of it, you might find this video interesting.

There is information about Carrier Command on Wikipedia. It seems to be abandonware and you can download just about every version on The House of Games.

There is a promising game trying to deliver a closer remake of Carrier Command than TnL. Intuitively titled Carrier 2, it has been around since 2003. You might want to nag the author for a demo version as he still hasn't released one (it's been "just around the corner" for ages now). This video looks gorgeous anyway.

Carrier 2 homepage.

For those of you who had problems with a missing libedit dependency, I prepared release 070710. Get it at the download page .

Update: There are now RPMs available for OpenSuse users on PackMan .

A new version of Thunder&Lightning has been released. User-visible changes include:

• An aircraft carrier that serves as take-off and landing platform for the Lightning aircraft, capable of self-defense with a deck turret.
• Water rendering: A GLSL shader renders realistically reflecting waves of machines with hardware shader support.
• A new Lightning cockpit with multi function display (currently only shows a magnifying view).
• Lots of work on AI.Drones can now take off and land on the carrier after performing their mission.
• Reworked missions that make use of the aircraft carrier. Extended tutorial mission.
• Yet again, enhanced flight model.
• Desktop integration: start TnL with a click on an icon.
• A new installation method: Autopackage.
  
• Bugfixes...

I hope you like it. Download Thunder&Lightning in the Download section. You can choose between a self-installing autopackage or a classic tarball as method for installation. Should you encounter problems, then the new Forum is the right place to find help.

 This release has been tagged "070707" in darcs.

The Thunder&Lightning discussion board is back open. I'll be glad to answer questions regarding usage or development in the respective forums.

This is another preview of the upcoming release of Thunder&Lightning.

The video showcases the new aircraft carrier, reflective water rendering and a slightly enhanced cockpit with a magnifying view.

What's less visible is the reworked AI. The complete flight of all three aircraft is performed by the autopilot. Whereas most of the flying is just following a predefined path, the landing is slightly more challenging. As you can see, the autopilot is dissatisfied with the first landing attempt and tries a second time. This happens sometimes as the approach path is kept aggressively short to enable multiple aircraft to land quickly.

The Lightning's cockpit has received a slight makeover. There is a big multifunction display. Actually, at the moment it's rather a single function display. It will become a real MFD though with functionality to replace the scrapped map of older releases.

Having a MFD will help to simplify gameplay a little. The only key a player will have to remember is TAB which will cycle between MFD states. This comes together with the decision to get rid of weapon groups. No more primary and secondary weapons. Left mouse button to fire and right mouse button to switch weapon. Middle mouse button to select target in HUD. TnL plays smoother this way.

The MFD uses the new multipass rendering functionality that was originally built into TnL to enable the water rendering. This opens up a lot of possibilities. And a lot of distraction too, since graphics programming is about the worst time sink thinkable to mankind. I will restrain from doing any graphics programming for the next couple of weeks!

Concentrating on gameplay functionality, I worked on unifying the various AI for aircraft, tanks and turrets (the carrier!). There was a large heap of unfinished work still in the code. Over time, I had experimented with various approaches to AI that were never really replaced, just superseded by new systems. Altogether, there were three different systems programmed in C++: The state-machine-like originally used for the drones (in 2002 or something), the hierarchical one used for tanks (where I wanted to make everything better and failed miserably) and the coroutine-using one for the drones that made combat more challenging but was integrated too badly into the original system to be of real use.

All these had the additional disadvantage of being written in C++. With its long compile times and static structure, C++ is not the best candidate for the kind of throw-away, quick-n-easy code needed for AI scripting. Writing a common AI for aircraft, tanks and whatnot is hard, and it's not something that is taught in computer science courses. The development in itself is a learning process where you never know what's waiting behind the next corner. This is where you need a script language. In the end, I scrapped a couple of thousand lines of C++ code in favor of a couple of hundred lines of Io code.

There is a price to be paid for the flexibility that comes with it, and it's called performance. Yes, doing the nitty-gritty work of keeping an airplane in the air inside the script language comes with a performance penalty. Right now, a couple of drones and tanks bring TnL to its knees on my (not so high-end 1.4GHz) machine. Before the change, AI performance was basically not a problem. I once created a mission where more than 200 drones were flying around and shooting missiles at each other at the same time. The only limiting factor was collision detection. Now the AI takes away a large percentage of time between two frames.

I might be forced to move some low-level parts into C++ again. But by then, these parts will at least be tried and proven.

So much for now, I hope you like the video!

What does a game programmer do if he is bored of adding gameplay features?

Right, he does some graphics programming! Here is the latest sugar for your eyes: A reflecting ocean surface. Those GLSL shaders can really make a difference. Have a look at the screenshots!