No, those are just flags that are not used by mappy, they are there for you to use in whatever way you want. They are called 'collision' in the editor simply for no reason other than giving them a name. They aren't really collision bits. Mappy gives you a set of user definable data items that you can use in whatever way:
- bit values (what you call collision)
- long data values
- short data values
- int data values
So you pick a value suited for your need. e.g. you want to store a flag to say the player can walk on it, use a bit value. Or if you have 8 different types of block types (e.g. can walk on if carrying a sword, cannot walk on, triggers another block, etc) then you'd maybe pick one of the short types.
For your collision you need to determine which direction the user is going (assuming no diagnal):
- RIGHT: get the block using the 'x+pacmanwidth',y
- LEFT: get the block using x,y
- UP: get the block using x,y
- DOWN: get the block using x,'y+pacmanheight'
Kind of thing.