Hello,
first and foremost thanks for a great tool. It has become a daily
workhorse for me.
And now down to a little bug a guy reported on the #atariscne IRC
channel last night: Saving Atari ST PI1 files results in (sort of) Atari
STe palette values.
So I decided to test it myself, and yes he was right.
Grafx2 version: 2.7.2978
Grafx2.app-x86_64-sdl2-2.7.2978.zip
OS: macOS Mojave 10.14
Method:
1. Create a 320x200 image
2. Set palette to 8 RGB-levels (divide five times)
3. Create a greyscale fade of 8 colours
4. Save as Degas Elite PI1
Normally that would look like:
$0000,$0111,$0222,$0333,$0444,$0555,$0666,$0777
GrafX2 outputs:
$0000,$0111,$0222,$0333,$0CCC,$0DDD,$0EEE,$0FFF
As I read that, RGB values above 3 gets the STe treatment (most
siginificant bit is set). This bit is ignored on ST machines but on STe
machines the image will look slightly different than intended.
The same issue resides with NEO images and I guess PC1 files (untested).
Also did a test with 16 RGB-levels (divide four times) with a 16 colour
greyscale saved as PI1 (STe colours) which came out correct.
$0000,$0888,$0111,$0999,$0222,$0AAA,$0333,$0BBB
$0444,$0CCC,$0555,$0DDD,$0666,$0EEE,$0777,$0FFF
--
Anders Eriksson
a...@dhs.nu