Linedef type 76
Linedef type 76, Make FOF Bouncy, is a type of linedef special that makes it so every tagged FOF becomes bouncy.
Binary Setup
The length of the linedef determines the strength of the bounce effect. For linedef lengths below 96 fracunits, the player will always reach the same fixed height with each bounce. For linedef lengths of 96 fracunits and above, the bounce effect becomes so strong that the height increases with each bounce until it reaches a certain value, after which the bounce height also becomes fixed.
For linedef lengths of 78 fracunits, the bounce height will decrease with each consecutive bounce until it reaches zero. For linedef lengths between 78 and 95 fracunits, the bounce height will also decrease with each consecutive bounce but eventually reaches a fixed height that is much lower than the original height.

UDMF Setup
Arg1 should be tagged to the FOF control linedef that should have the bounce effect. Arg2 determines the strength of the bounce effect. For values below 96, the player will always reach the same fixed height with each bounce. For values of 96 and above, the bounce effect becomes so strong that the height increases with each bounce until it reaches a certain value, after which the bounce height also becomes fixed.
For values of 78, the bounce height will decrease with each consecutive bounce until it reaches zero. For values between 78 and 95, the bounce height will also decrease with each consecutive bounce but eventually reaches a fixed height that is much lower than the original height.

Sample (Binary)
 Example file: Ex_ld076_makefofbouncy.wad
This map contains two bouncy FOFs, with the red one having a strength of 128, and the blue one with a strength of 64.
Sample (UDMF)
 Example file: Ex_ld076_udmf_makefofbouncy.wad
This map contains two bouncy FOFs, with the red one having a strength of 128, and the blue one with a strength of 64.