There are several options in the MSX scene to create the necessary sprites for homebrew videogames, but in all the possible options we tried, we couldn’t find any that offered us to mount sprites in overlapping to see the OR effect (palette color mixing). The Video Display Processor (VDP) V9938 chip of MSX2 computers can do this special effect.
Sprites for MSX2 VDP have 1 color only in each line. With the OR effect, you can put more than one color when sprites are overlapped. With SEV9938 you see this effect in real time with testing on a real MSX.
On the screenshot above, you can see the main character from Stan, the dreamer for MSX2 built with 3 sprites overlapped using SEV9938 Sprite Editor.
This editor is PC computers. And published demo is for Windows. But its code, written in C++ and using handful libraries as DearImGui and SDL, can be compiled in Linux too.
It’s still in beta, but you can download a demo. Please take a look in SEV9938 itch.io page.
I’m looking for MSX2 graphic artists beta testers. Do you want to be one? Please contact me here or on twitter: @jamqueTPM.