Overview

Allows you to change the speed of an action while the action is running. Useful to simulate slow motion or fast forward effects. Can also be used to implement custom easing effects without having to create your own CCActionEase subclass.

You will need to keep a reference to the speed action in order to change its speed property. It is best to assign the speed action to an ivar or property with the __weak (ivar) or weak (@property) keyword.

For instance:

@implementation YourClass
{
    __weak CCActionSpeed* _speed;
}

Now you can create an action whose speed you want to be able to alter while the action is running:

id move = [CCMoveBy actionWithDuration:60 position:ccp(600, 0)];
_speed = [CCActionSpeed actionWithAction:move speed:1];

The speed factor of 1 will start running the move action at its normal speed. Later when you determined that it’s time to change the speed of the move action, just change the _speed action’s speed property:

-(void) update:(CCTime)deltaTime
{
    if (slowMotionMode) {
        _speed.speed = 0.2f; // move at one fifth of the regular speed
    } else {
        _speed.speed = 1.0f; // move at regular speed
    }
}

When the move action has run to completion it will end and thanks to the __weak keyword and ARC the _speed ivar will automatically become nil.