A_BubbleRise

A_BubbleRise is an action that is used to make the actor rise upwards. Var2 determines the increase in vertical speed in fracunits to give the actor (the value of which should be multipled by FRACUNIT); when this action is used repeatedly, this will make the actor accelerate upwards (or downwards, if Var2 is a negative number). If Var1 is set to 0, the actor will be thrusted slightly in a random horizontal direction – when this action is used repeatedly, this will make the actor appear to be "bending" around the water. If Var1 is set to 1, the actor will not move horizontally at all and will simply rise directly upwards.

In SRB2, this action is used by all forms of bubbles in the game – these are commonly associated with the Air Bubble Patch, but the player will also spawn small/medium-sized bubbles if they are breathing underwater without an Elemental Shield, have just fallen into the water from above the water's surface, or when swimming as Tails or other characters with the ability to fly (CA_FLY).

Note that if the actor's Object type is MT_EXTRALARGEBUBBLE (the breathable bubble), Var1 and Var2 will have no effect for this action; instead, the actor will rise directly upwards at a constant speed of 1.2 fracunits/tic (6*FRACUNIT/5), rather than accelerating upwards as other Object types would when using this action.