Could I manage interpolation for NSDockTile.contentView?

I have a question about the content of the custom NSDockTile view. 

For example, I have several CALayers figures (pic 1)

Initial information:

First of all, I added green figure L on contentView's layer. Then I added figures R1 and R2. R1 and R2 are the same but the R1 figure has a Y offset (just several points).

So I expect that R1 and R2 will cover green figure L.

But because of interpolation, I can have an effect of the wrong overlay. I mean the case when figure L seems to cover figure R1.

I have a custom view that I set here NSApp.dockTile.contentView

and use NSApp.dockTile.display() to update the icon.

pic 1 - figures

Question:

How can I manage the interpolation for the contentView?

Should I create my own NSImage and set it as a dock icon? 

Or will I get some results at the end?

The main question is how can I fix or improve it.