public void Spawn(GameObject projectilePrefab, FiringSolution solution)
{
var body = Instantiate(projectilePrefab);
var projectile = body.GetComponent <ProjectileComponent>();
var spawnPosition = transform.position;
projectile.Shoot(spawnPosition, solution);
}
protected void ShootProjectile(FiringSolution solution)
{
foreach (var barrel in _barrels)
{
barrel.Spawn(ProjectilePrefab, solution);
}
OnShot();
}
public void Shoot(Vector3 position, FiringSolution solution)
{
var body = GetComponent <Rigidbody>();
transform.position = _startPosition = position;
transform.forward = solution.FiringDirection;
body.MovePosition(position);
body.velocity = Velocity * solution.FiringDirection;
Solution = solution;
}
private static FiringSolution?TrySolve(Vector3 projectilePosition,
float projectileVelocity,
float projectileRange,
Vector3 targetPosition,
Vector3 targetVelocity, float targetAcceleration)
{
// We need to solve "v1*t = a2*t + v2*t"
// Where v1 is our projectile's speed, v2 is the rocket's speed and a2 is the rocket's acceleration.
// The following solution is a simple iterative approach that starts with a wrong solution, calculates
// the error and then tries to find the solution where the error is minimal.
var distance = Vector3.Distance(projectilePosition, targetPosition);
var flyingTime = distance / projectileVelocity;
FiringSolution?solution = null;
const int maxIterations = 10;
for (var i = 0; i < maxIterations; ++i)
{
// x = at²+vt
var futurePosition = targetPosition +
targetVelocity * flyingTime +
targetAcceleration * Mathf.Pow(flyingTime, 2) * targetVelocity.normalized;
var firingDirection = futurePosition - projectilePosition;
var finalDistance = firingDirection.magnitude;
var finalFlyingTime = finalDistance / projectileVelocity;
if (IsProperSolution(projectilePosition, targetPosition, futurePosition, finalDistance, projectileRange))
{
solution = new FiringSolution
{
TargetPosition = futurePosition,
FiringDirection = firingDirection / finalDistance,
InterceptionDistance = finalDistance
}
}
;
flyingTime = finalFlyingTime;
}
return(solution);
}