Find meeting point of 2 objects in 2D, knowing (constant) speed and slope
- by Axonn
I have a gun which fires a projectile which has to hit an enemy. The problem is that the gun has to be automatic, i.e. - choose the angle in which it has to shoot so that the projectile hits the enemy dead in the center.
It's been a looooong time since school, and my physics skills are a bit rusty, but they're there. I've been thinking to somehow apply the v = d/t formula to find the time needed for the projectile or enemy to reach a certain point. But the problem is that I can't find the common point for both the projectile and enemy. Yes, I can find a certain point for the projectile, and another for the enemy, but I would need lots of tries to find where the point coincides, which is stupid. There has to be a way to link them together but I can't figure it out.
I prepared some drawings and samples:
A simple version of my Flash game, dumbed down to the basics, just some shapes:
http://axonnsd.org/W/P001/MathSandBox.swf - click the mouse anywhere to fire a projectile.
Or, here is an image which describes my problem:
So... who has any ideas about how to find x3/y3 - thus leading me to find the angle in which the weapon has to tilt in order to fire a projectile to meet the enemy?
EDIT
I think it would be clearer if I also mention that I know: the speed of both Enemy and Projectile and the Enemy travels on a straight vertical line.
