How to detect number of nodes involved in a collision in SpriteKit

Question

I am creating a shooting game where I am shooting projectiles from one node targeted at enemy projectiles. When the projectile makes contact with two enemy nodes simultaneously, the contact delegate gets called twice. I want to be able to know how many nodes the projectile has come in contact with in order to give the player a 2x bonus.

Can anybody suggest a clean and efficient way to achieve this?

Answer 1

So, I went with the suggestion by Dobroćudni Tapir in the comments section.

Added a variable called hitCount as a property of the subclassed projectile SKSpriteNode.

@property NSUInteger hitCount;

Then in the didBeginContact of the scene

-(void)didBeginContact:(SKPhysicsContact *)contact
{
    SKNode *firstBody;
    SKNode *secondBody;
if (contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask)
    {
        firstBody = contact.bodyA.node;
        secondBody = contact.bodyB.node;
    }
    else
    {
        firstBody = contact.bodyB.node;
        secondBody = contact.bodyA.node;
    }

    if (firstBody.physicsBody.categoryBitMask == projectileCategory && secondBody.physicsBody.categoryBitMask == delusionCategory)
    {
        //Other logic

        RCCProjectile *projectile = (RCCProjectile*)firstBody;
        projectile.hitcount ++;
        [projectile removeFromParent];
    }
}

Then, finally in the projectileNode, I overrode the removeFromParent method

-(void)removeFromParent
{
    if (self.hitcount >= 2)
    {
        [(LevelScene*)self.scene showBonusForProjectile:self];
    }

    [super removeFromParent];
}