Blocky Skies - My first Amiga game

[alpine9000]

I am getting close to finishing my first Amiga game and I thought I would post some details here for other newbies thinking of doing something similar.

TLDR - download demo from blockyskies.com. Full game/tools source code https://github.com/alpine9000/blockyskies.

@nobody came up with the idea for doing this game and he did all of the artwork. @saimon69 is the musician.

The game is 100% assembler/hardware. It is cross compiled on a mac using vasm/vlink and a handful of tools that I wrote in C to convert the graphics assets into Amiga format data.

In order to actually get something finished in a reasonable timeframe, I banned refactoring unless the frame rate fell below 50fps or the code compromised the game. This rule has resulted in some quite hard to understand routines but I did get something finished. In around 8 weeks of working a handful of hours a week a basic game was ready.

It uses quite a lot of the Amiga hardware features including:

• Two Independently scrolling play-fields (foreground/background).
• The copper switches screen modes mid-screen for the status/message panels.
• The copper switches palettes many times each frame.
• The blitter is used for all drawing (probably in some cases where it should not be ).
• Hardware sprites are used for all of the items that appear on the board. Sprites are re-used vertically (not horizontally).
• Three audio channels are used for the P61 music player, the other channel is used for sound effects.
• A hardware track loader (thanks Photon) is used to load data directly from the floppy.

The build creates both a trackloaded ADF and a Workbench launch-able executable. At the moment the trackloaded version runs with 512kb of ram and the Workbench version requires about 650kb of free chip ram.

I used FS-UAE and WINUAE extensively to debug the game. This saved me a lot of time. Learning the full power of the UAE debugger would be my #1 recommendation for anyone thinking of developing a trackloaded hardware game. My hacked version of FS-UAE makes this even easier by giving me debug symbols and command line history/completion.

The other slightly different thing I did was to use a vlink linker script to keep track of ram usage, making it very easy to know when I had blown the 512kb chip ram limit.

I found coding asm on Amiga hardware to be super fun and surprisingly painless, so I can't wait to get started on the next game.

[hooverphonique]

Good effort and nice write-up :-)

[alpine9000]

Originally Posted by hooverphonique

Good effort and nice write-up :-)

Thanks, I probably should have mentioned that I am close to releasing a test of the workbench launch-able version.

If that tests out OK (and we have finished the levels/music) then I will put out the final version and it will be time to start on the next game

[Steve T]

Good effort all! Great to see more software coming along.

[kamelito]

Nice to see a new Amiga game, and with the source code congrats!
Kamelito

[DamienD]

Very good work indeed alpine9000 (and nobody + saimon69)

[Amiga1992]

This looks interesting!

I have to ask though: what is the main sprite supposed to be? I can't figure it out :/

Great job!

[alpine9000]

Originally Posted by Akira

This looks interesting!

I have to ask though: what is the main sprite supposed to be? I can't figure it out :/

Great job!

In the full release there is a different sprite each level.

The sprite in the video on the site (kaboom level) is a tank, and for the demo version it's a flying pig

[alkis]

Nicely done!

[Amiga1992]

Originally Posted by alpine9000

In the full release there is a different sprite each level.

The sprite in the video on the site (kaboom level) is a tank, and for the demo version it's a flying pig

I see, taking after crossy road and stuff.
Nice one.

[amiman99]

Looks interesting, I'll try it for sure.

[Mrs Beanbag]

oh! looks nice! i love the idea... a memory game

[Franchute13]

Hi Alpine9000!
Excelent!
Thank you for the source code and the game!!!

[phx]

Originally Posted by alpine9000

The game is 100% assembler/hardware. It is cross compiled on a mac using vasm/vlink and a handful of tools that I wrote in C to convert the graphics assets into Amiga format data.

That's the way to do it!

I see you used the free portable Tiled editor for the maps. I also plan to do that for my next game.

[alpine9000]

Originally Posted by phx

That's the way to do it!

I see you used the free portable Tiled editor for the maps. I also plan to do that for my next game.

Yes Tiled is cool. I didn't really use many features and ended up using hard coded tile addresses to determine tile properties which I might not do again if I had my time over again.

[alpine9000]

I uploaded a test release of a hard drive installable version to the website. It requires about 600kb of free chip ram.

I tested it as thoroughly as I could in UAE, but my workbench knowledge is 20 years old and only extended to 2.0....

So if anyone is brave enough to try it on real hardware I would be very grateful

[andyhants]

Great little game mate well done!

[Superman]

HD version works fine on my A1200 with CF drive.

[alpine9000]

Originally Posted by Superman

HD version works fine on my A1200 with CF drive.

Thanks, I appreciate you taking the time to test it

Did it quit back out to workbench OK ?

[Superman]

Originally Posted by alpine9000

Thanks, I appreciate you taking the time to test it

Did it quit back out to workbench OK ?

Yes it did indeed.