Cropping an overlay without /icon ops.

ID:2216277
 
Feb 21 2017, 12:05 pm
Problem description:
So somebody on our humble SS13 fork ported see-through cryo tubes from another server. The PR is still awaiting merge because of a graphical issue we can't figure out a way to solve.

Basically, the cryo tubes now have an overlay of the human in between them and a semi transparent lid, like this:



As you can also see from the image, large items stick out.

So after many failed attempts me and a couple other people trying to fix this mess got as far as to put the tube into KEEP_TOGETHER and to then simply add a "cutter" overlay on BLEND_SUBTRACT! Of course that's the perfect sol-

crap


(may be hard to see but there's four pixels of black sticking out)

We're getting the pixels black but not transparent.

Trying a colour matrix to cut out black pixels didn't help anything either because of KEEP_TOGETHER or something else.

So we're out of ideas. Any help getting this human overlay to be restricted to the bounds of the tube?
Feb 21 2017, 3:51 pm
Set the cyro tube's color to
list(
0,0,0,0,
0,0,0,0,
0,0,0,0,
0,0,0,255,
1,1,1,0
)

Set the human's color to that as well. Multiply them both together. Multiply the result with the base human sprite. The end result should be the human sprite cropped to the cyro tube's boundaries. Set the final object to KEEP_TOGETHER so the multiplies don't leak onto other objects.