Make variables for touchstartx and touchstarty and check them against touch.x an touch.y to see the general direction of the movement is.Ok, there's a start. Many projectiles were created this way. so I did this:
"trigger once" create projectile
"touch 0 speed >5000"
"touchstartx+300<touch.x" set bullet speed...
set bullet angle...
Sometimes this works, but mostly projectiles will only go the right. I have no idea why.