Creating a total new GRF file [help wanted]

[Dribbel]

I want to add something totaly new (eg a spaceport/ a looping/whatever) and i don't want to sacrifice any existing thing so i need an extra GRF file with my stuff in it.

I did some research on the grf stuff, i know how to use them in the code (i can program ) but i keep having a hard time getting my grf file right

1)
I start with the image below and a correct before NFO file

(click it for pcx version)

2)
encode it using the grf encoder.

3)
I decode it again if thing went correct. I end up with something like this:

after_test.nfo

What is going wrong here, i don't know. Please help

[Patchman]

Your PCX file must have an even X dimension. Odd won't work.

[Dribbel]

Thanks! I' try that! Was that somewhere in de docs or specs?

--edit
hmm it's even: 800px

[dominik81]

Why don't you just add them to openttd.grf? Or you could rename openttd.grf to mygraphics.grf and remove all the graphics you don't want from that file.

[Dribbel]

i think i'll do something like that. Making a new one is quite hard.