public static void HandleCollision(this ICollidable me, ICollidable target)
{
// Reference frame: target is standing still (this makes calculations easier)
// Adjust velocities to fit the reference frame
Vector3 otherInitialVelocity = target.GetVelocity();
Vector3 initialVelocity = me.GetVelocity() - otherInitialVelocity;
// Target will be sent directly away from my center of mass
Vector3 directionTowardsOther = (target.GetPosition() - me.GetPosition()).normalized;
// Get my initial kinetic energy
// My KE is equal to the total KE of the system, because the target is stationary in this reference frame
float initialKineticEnergy = (0.5f * me.GetMass() * me.GetVelocity().sqrMagnitude);
// How much KE is transferred to the target depends on how direct the hit was
float kEPercentage = Vector3.Dot(directionTowardsOther, initialVelocity.normalized);
float transferredKE = initialKineticEnergy * kEPercentage;
// Elasticity determines how much KE is converted into damage and how much becomes recoil
float elasticityAvg = (me.GetElasticity() + target.GetElasticity()) / 2f;
float recoilKE = transferredKE * elasticityAvg;
float convertedKE = transferredKE - recoilKE;
// Get the new speed of the target from the recoil KE and set velocity in the direction of impact
float theirSpeed = Mathf.Sqrt(Mathf.Abs(2f * recoilKE * kEPercentage) / me.GetMass());
Vector3 theirNewVelocity = directionTowardsOther * theirSpeed;
// Calculate my new velocity using the conservation of momentum formula
Vector3 myNewVelocity = initialVelocity - ((target.GetMass() * theirNewVelocity) / me.GetMass());
// Set velocities of both bodies, shifting back to the global reference frame
me.SetVelocity(myNewVelocity + otherInitialVelocity);
target.SetVelocity(theirNewVelocity + otherInitialVelocity);
// Take damage based on the converted KE
me.TakeDamage(me.CalculateCollisionDamageReduction(target.GetDamage(convertedKE)), false, VectorHelper.Midpoint(me.GetPosition(), target.GetPosition()));
target.TakeDamage(target.CalculateCollisionDamageReduction(me.GetDamage(convertedKE)), false, VectorHelper.Midpoint(me.GetPosition(), target.GetPosition()));
// Move to positions so the colliders aren't inside each other
float totalMaxRadius = me.GetCollisionRadius() + target.GetCollisionRadius();
float actualMaxRadius = (target.GetPosition() - me.GetPosition()).magnitude;
float radiusDifference = totalMaxRadius - actualMaxRadius;
float myRadiusPercentage = me.GetCollisionRadius() / totalMaxRadius;
Vector3 weightedMidpoint = me.GetPosition() + directionTowardsOther * actualMaxRadius * myRadiusPercentage;
target.SetPosition(weightedMidpoint + directionTowardsOther * target.GetCollisionRadius());
me.SetPosition(weightedMidpoint - directionTowardsOther * me.GetCollisionRadius());
// Communicate collision to parent spawner if other is player ship
try {
ISpawnable spawnable = (me as MonoBehaviour).GetComponent <ISpawnable>();
PlayerShipController playerShip = (target as MonoBehaviour).GetComponent <PlayerShipController>();
if (spawnable != null && playerShip != null)
{
spawnable.GetParent().SavePlayerCollision(playerShip.transform.position);
}
}
catch (System.Exception e) {
Debug.LogWarningFormat("Using ICollidable that isn't a MonoBehaviour! How?/nInner Exception: '{0}'", e.Message);
}
}
