Just posting this as log.

About these 4 slopes, actually they are just are copy of one slope of same type. Just with different rotations.
It's tricky because they can have different shape, if slope has LID face then it has one shape, if it doesn't have LID then it has second shape or form.
I completed one slope, now i will just mathematically rotate it (thanks to nxPascal great and neat code again) but rendering of these slopes is also tricky, including picking. I saw that when messing with these 4 slopes i messed up drawing of some faces for other slopes.
The block (or slope) drawing code tries to be general for all slopes. But if there is bad boolean logic, it messes up other faces. The code is also pretty messy atm. I must rewrite it. The whole logic is there just few boolean functions returning me "true" or "false" and some logical boolean ops like "and "or" "not".
It's very boring stuff to work on, but i must fix this asap. How the map is rendered and how the picking works depends on this stuff.

Now i gtg to work.

Bye.