Shooting prediction algortithm in java

Question

I have an issue in my current game dev hobby. I have two units, which are hostile in 2D space. One is shooting directly at the opponent, so if he moves it misses. But the other should predict it's opponents movement and shoot "ahead".

Let's assume first unit is A and second one is B. I can calculate their distances and I have their viewing angle and I have the speed at which they are moving. (player speed and bullet speed are different constants)

I tried with approximations to calculate distance between A and B and then use the Bv and orientation angle to calculate where the B will be in the next second and then scale that by the distance of two players divided by the bullet speed. But this is very inefficient and does not work well.

float distanceK = MathUtil.distance(unit.x, unit.y, opponent.x, opponent.y) / Constants.BULLET_VELOCITY;

float x = (float) (opponent.x + (Constants.UNIT_FORWARD_VELOCITY * distanceK * Math.cos(opponent.orientationAngle)));
float y = (float) (opponent.y + (Constants.UNIT_FORWARD_VELOCITY * distanceK * Math.sin(opponent.orientationAngle)));

float angleToRotate =  MathUtil.angleBetweenUnitAndPoint(unit, x, y);

In the example above I then use angleToRotate variable to determine how much do I have to rotate to hit opponent, but the rotation too takes some time (54deg/s)

I would need a more optimal solution for this problem.

a) predict opponent movement when you are standing still.

b) predict opponent movement when you are moving.

Answer 1

You could use a vector representation of the space. So BA would represent the vector between A and B from A's point of view. You could then add the vector Bv of unit B's velocity. The resultant vector would be the vector between B and Bvp the predicted position of B at some time t in the future. As for a moving calculation, you'd need to also account for the movement vector of A.