Currently, I try to add some sort of area highlight for my mod. While i were doing this, I noticed, that if I draw poly or anything else rather than line, i have to draw it from both sides.
For example, if i draw horizontal quad, i have to draw it twice, one for view from top, second one for view from bottom.
First question: is there a way to draw both sides without duplicating 4 vertex with a bit different order(like on pic above)?
https://pasteboard.co/GIzevKV.png
Second question: why is happening on pic above?
https://pasteboard.co/GIzfiWJ.png
Is there any normal way to control that? in some cases i would prefer if the alpha wouldn't stack, in another case the opposite - so it would stack.
Any kind of suggestions are welcome.