how does writepixel/writepixelfast alpha work?  

title is self explanatory, how does the alpha channel get used with the writepixel command?

this old thread could shed some light https://archive.blitzcoder.org/forums/b3d-programming/32428.html

a code example on how to use these functions :
https://www.blitzcoder.org/forum/topic.php?id=1538&post=1

so it's mostly unused other than for images/textures? alright, thanks