Detecting what tile under sprite

I'm practicing on making a platformer. right now trying to make enemy that patrols back and forth over bunch of tiles. think of it like Mario's enemies how they go back and forth. for that i need to detect if the enemy is about to reach the end of the tiles so then it can reverse its direction.   How do I achieve this? I tried to search the forum, but may be I didn't use right terms.

I tried using specific tile x and width, I was able to make it reverse direction on reaching the start, but reaching the end I couldn't because as far as i can see there is no way to detect how many tiles arranged in that area to calculate the end of that particular platform.

I tried using sin movement, but then this will be a problem since platforms are not equal in length.   also I didn't find a way to detect in what direction that movement of the sin is going into so that I can mirror the sprite.

In sum: How to detect what tile/sprite/object exist in specific x y?

thanks

I thought now of different approach, by having invisible walls for enemies if on collision reverse direction. still if someone knows how to detect what object on x,y, please share. thanks

You can achieve this by using "Is overlapping at offset".

Here's an example I whipped up.

Example .capx

Basically just checks if there is a floor a certain distance to the right or left depending on the direction it's moving and then changes directions accordingly.

Thanks a lot! that exactly what I was looking for.

No problem :)

Here's a 2 event version using ternary operation. I'm bored ^^;

Example2 .capx

thanks Tokinsom, unfortunately, I can't view the file because it says different version, I need to download the beta. I ll do that today and have a look. thanks (; I appreciate it.