Recent changes to 6: Level editor for Hex-a-hop

#6 Level editor for Hex-a-hop

Rolf Sander — Wed, 22 Apr 2026 07:29:26 -0000

Here is an update on my level editor for Hex-a-hop. I can now modify the
levels.dat file and create arbitrary new levels. The source code of the
game remains unchanged, all you have to do is replace the original
levels.dat by the modified version. An example is attached. Please try
it! There are several new levels (all solvable), plus some dummy levels.

To create your own levels, you currently have to modify some variables
inside a Python script. If there is sufficient interest, I can make the
code available and write some documentation.

BTW: I found an Easter egg in the game. There is an additional tile
called "switch" which switches between flat green tiles and green hills.
It hasn't been used in any of the 100 standard levels, but it works
perfectly fine when you use it in your custom-made levels :-)

#6 Level editor for Hex-a-hop

Rolf Sander — Thu, 05 Feb 2026 12:15:16 -0000

Thanks for your feedback, Paul!

My approach is basically the same as what you had planned: First,
decompile levels.dat back to some readable ASCII files. Then, write a
level editor that works with these ASCII files.

So far, I've been able to locate the individual levels in levels.dat.
Inside each level, I can see the hexagonal map (more details below). I
can even change individual bytes in levels.dat and get different tiles
when restarting hex-a-hop.

What I'm still struggling with are the bytes before and after the tile
definitions. I assume they define the width and height of the hexagonal
map. Also, there must be the starting position of Emi somewhere.
Deciphering these bytes is where I mostly need help, as I cannot find
the part of the code where these bytes are read and applied.

As an example, here is the 2nd level (called "Hive"). The header is:

18 00 00 00 03 00 00 00 01 08 07 0d 01 00 00 00 0b 00 00 00 00 00

Next, the layout of the tiles:

00 00 02 02 00 00
00 02 02 00 02 02 00
02 00 02 02 00 02
01 02 02 00 02 02 01
02 00 02 02 00 02
00 02 02 00 02 02 00
00 00 02 02 00 00
00 00 00 01 00 00 00

If you flip this along the main diagonal, you can recognize the
hexagonal map of the "Hive" level (00=water, 01=gray, 02=green).

Finally, there is a footer:

00 00 89 00 00 00

If I manage to understand this syntax and write some sort of level
editor, I will of course make my code and data publically available.

#6 Level editor for Hex-a-hop

Paul Wise — Thu, 05 Feb 2026 05:15:34 -0000

I inherited the project from the original author @amuzen, unfortunately they didn't document the format apart from the source code in packfile.h and they didn't release the source level files. I have been meaning to decompile levels.dat back to some sort of source level files and then delete the levels.dat file from git, but I never got around to it.

Looking at the code, I see there might already be some form of level editor that is enabled when you define an EDIT macro, and I got it to compile and run (see attached diff), but I wasn't successful getting to do anything useful and I don't know the keyboard shortcuts for it yet.

I think it would be great to remove the EDIT macro and instead enable the edit mode when a menu option is enabled, if you would like to work on that, then I will definitely review and merge any patches you write.

Any other help you can give on Hex-A-Hop would be very appreciated.

@guillemj is the most recent person to work on Hex-A-Hop btw.

Level editor for Hex-a-hop

Rolf Sander — Wed, 04 Feb 2026 20:02:19 -0000

I would like to create new levels, and maybe write a small level editor
for Hex-a-hop. AFAICS, I can achieve this by editing the levels.dat
file. Is there a description of the syntax of this file? Any help is
appreciated!