Good, @dani-0tb. This has been talked about in length, however.
Here it is as a single function that makes use of existing flags for sprites. Those light-bulbs just below the 16-colors on the spritesheet.

https://www.lexaloffle.com/bbs/?tid=36388

amazing thanks a looot

You are very welcome, @dani-0TB. We can all learn from each other. :)