Board Thread:Questions and Answers/@comment-1490123-20141212021752/@comment-14600979-20141212022739

You need a measure for how far into the slope tile you are. (FLOOR(XMOVEMENT/8)*8) - XMOVEMENT would give you it.

You also need that for Y. I'll call them BLOCKX and BLOCKY. Also, the specific slope of the tile being collided with is called TILESLOPE below.

Then you check something like