Spritekit is a SKSpriteNode facing another SKSpriteNode

Question

I'd like to find out if a sprite is facing another sprite? For instance I would like to make a player have the ability to shoot a monster if he is pointing his gun anywhere between the length of the monster. Please help!

Answer 1

To determine if the player node is facing the enemy node, you will need to calculate the angle between the nodes (see angle theta in Figure 1).

Figure 1 Diagram showing the angles between the nodes in the scene

Calculate theta by taking the inverse tangent of the difference in y divided by the difference in x:

    CGFloat dx = enemy.position.x - player.position.x;
    CGFloat dy = enemy.position.y - player.position.y;

    theta = atan2f(dy, dx);

If the difference between theta and the player's zRotation is small, the player is facing the enemy.

   if (fabs(theta-player.zRotation) < maxDifference) {
        // Do something here
   }