Sprite rotate according to their trajectory

How do I rotate the sprite according to the trajectory?

<img src="http://i244.photobucket.com/albums/gg36/some9000/T1.png" border="0" />

how do I make the sprite "follow" the trajectory = rotate according to their movement path.

<img src="http://i244.photobucket.com/albums/gg36/some9000/T2.png" border="0" />

Thanks.

Save the old position of the object at the end of every tick and set it's angle at the beginning of every tick to the angle from the old position to the current as calculated by the angle() expression.

EVERY TICK:

set sprite angle to angle(oldx, oldy, sprite.x, sprite.y)

set oldx to sprite.x

set oldy to sprite.y

Alternatively have an invisible sprite "lead" as your projectile, attach the visible one to it via a physics joint, and set your angle to the invisible sprite.

Just a theory.

Thank you for answers :)

you guys could put a capx ?

thanks

R0J0hound

I have a problem in angle(oldx, oldy, sprite.x, sprite.y)

Unknown expression 'oldx'

oldx is a variable you have to create.