Background collisions, SFX and TURBO!

Well, today went really well, I fixed up my collision routines with the scrolling background, yup, it was using a simple offset, with a case for looping every 32 row increments, seems to work well. Possibly un-optimised but good enough so far.

There’s some rudimentary noises from both cars on screen based on their speed and distance from each other, also collision noises are in there now.

The fuel-o-meter has turned into a working turbo bar to help catch-up or overtake other racers. It’s getting there, but I’m down to 4kb of ROM remaining now and the racer A.I. needs improving on the sly. I’d like to get some BGM in there also somehow.

CPU Usage is getting pretty high now though, so I may need to inestigate into other ways to load my level up. Setting colours for each tile through a switch is probably slower than referencing another variable directly I imagine but, well, a balance needs to be struck.

Tomorrow I’ll most likely be sorting out the code into banks to save space and going from there with more advanced A.I. (Not simple homing, falling of the track A.I.) those cars need to fall foul to going off track also and that’s going to be inetresting to set-up correctly!

Screenshot tonight is from the gameboy classic mode where, yes. Identical cars. I’m not too fussed about that. I am fussed about adding some steering animation though!

Getting There

How To Get Started with Gameboy Development using GBDK

So, you’ve decided to make a Homebrew Gameboy Game using GBDK, Good for you! Let’s get you up and started with some of the vital tools that you’ll need.

  1. GBDK – GBDK Download & Install Guide
     ( I installed my copy to C:\gbdk and will refer to that location throughout this series of tutorials.)
  2. A Text Editor. Programmers Notepad is pretty nice and FREE
  3. BGB (Gameboy Emulator, again FREE and the best one out there.)

Please note that I’ve only done GBDK coding on my Windows Machine so some installation bits may vary depending on your choice of Operating System.

That’s it, that’s the bare minimum you’ll need to get started and get used to bare minimums, because the Gameboy, despite being a well-balanced machine, isn’t powerful, if you’re used to Unity or other modern development tools, this will be quite the step back. Let’s take a brief look at the specs

Yay Gameboy!CPU Speed: 4.19 MHz ( or 0.000419 GHz if you prefer)
RAM: 8kb – Expandable to 32kb depending on your ROM Carts settings

And we’re looking at ROM Sizes between 32kb to I think 1Mb. Not much space, and to start we’ll be dealing with 32kb ROM Size only.

Everything Graphical is Tile-based (8×8) and we have a screen resolution of 160 x 144 Pixels, In 4 shades of grey.

And yes, you can still make a game, running at nearly 60FPS on this, cool huh?

Tomorrow we’ll write our first program which will cover that most important thing, getting something on-screen with a few lines of code and running, it’ll be great!

Racing for Position!

Sprite to sprite collisions are a-okay! The cars react according to where they have been hit from and, whilst i need to add another check for differing speeds, there’s more of a racing feel to the game.

Position checking is done with 2 well-timed comparison tests and works well, I doubt I’ll add a qualifying section to this game as passing opponents should be the main focus of this game.

But, I still have to sort out background collisions still, gyahhh! Nahh, it’ll be fine, just gotta hope I don’t exceed the CPU limits, collision detection takes surprisingly little!

After a brief check on the space left in the bank, I’ve got a little over 5kb of ROM to spare. Not much, but hopefully, enough, most of the functions can be contained in their own bank which will free up a fair amount so there is some wiggle room to play with.

As always, screenshot for you down below…
passing-for-position