How to move gun projectile in state line
<p>I have spawn point of projectile and I have to move it in state line direction but I don't know the destination point. So what formula or concept I will have to write to go in state line of projectile.</p>

<p>Suppose spawn point is (4,5) so it should go towards the direction (-4,-5), for any coordinate value.
Thanks in advance</p>
