[General] Detect units if they're seen by players

[FUJI]

How to detect if the unit is in visibility fog of war or black mask.

Because I'm making AI Casting a carrion swarm in 3000 range and the carrion swarm ability has a cast range of 3000.
The problem is he can cast the carrion swarm to the enemy units in 3000 range even there's no a vision to the picked unit.

 

[Imp Midna]

constant native IsVisibleToPlayer           takes real x, real y, player whichPlayer returns boolean
constant native IsFoggedToPlayer            takes real x, real y, player whichPlayer returns boolean
constant native IsMaskedToPlayer            takes real x, real y, player whichPlayer returns boolean

Try to check if the location the unit is standing on is visible

 

[FUJI]

^ Thanks for the natives ^^ +rep