Id even say that indirect fire was around long before directed fire. To aim a weapon by looking down the barrel and pointing it at the target you need projectiles at very high velocities. Catapults and trebuchets would fire in a very distinctive arc and as said, even with a bow or thrown spear, you have to fire or throw in an arc unless you are at point blank range tothe target.
If you can see the target you are aiming at or not, mostly depends on high its cover is. But to point the weapon directly at the target, you would have to be either very close or fire at very high velocity.