Gets the value of the velocity imparted to the player by a hit. You must specify the component that you want to check, eg. "HitVel Y" to check the vertical velocity component.

Format: HitVel [component]

Arguments:

- [component]: X, Y

Return type: float

Error conditions: none

Details:

A positive HitVel Y means that the player is moving upward on the screen. A positive HitVel X means that the player is moving backward. Note that the HitVel X trigger behaves in the opposite manner to the Vel X trigger.

Example:

`trigger1 = HitVel X > 0.5
; True when the player's gethit x-velocity is greater than 0.5 pixels per tick.`