Tick Loop

Dreamlab runs at a fixed, customizable tickrate. By default, the engine will tick 60 times a second. During a tick, the engine will update entities and run the onTick functions in your Behavior scripts. A fixed tickrate is advantageous because it means you don't have to constantly refer to a delta time eveywhere in your scripts and makes networking simpler.

Ordering

During a tick, the following happens:

1. All entities tick, updating their visuals, physics bodies, tranform, etc.
2. All Behaviors run their onTick methods
3. All Behaviors run their onPostTick methods
4. Entities and their attached Behaviors under the world tree is synced over the network

Behaviors do not tick in a guaranteed order. If you absolutely need to guarantee that one Behavior ticks before the other, it's recommended you refactor your code to enforce ordering using function calls; for example the following is incorrect:

class BehaviorOne extends Behavior {
  onTick() {
    // prepare some data that BehaviorTwo needs
    this.prepareSomeData();
  }
}
class BehaviorTwo extends Behavior {
  onTick() {
    // BAD, not guaranteed to run after BehaviorOne.onTick!
    this.consumeData();
  }
}

The correct way to script this would be:

class BehaviorOne extends Behavior {
  onTick() {
    // prepare some data that BehaviorTwo needs
    prepareSomeData();
    this.game.entities
      .lookupByBehavior(BehaviorTwo)
      .forEach((entity) => entity.getBehavior(BehaviorTwo).consumeData());
  }
}

This is relatively niche and you probably won't need to do this. Most of the time, you'll be able to use onTick and onPostTick, detailed below, to solve ordering problems.

onTick vs onPostTick

onPostTick is always guaranteed to run after onTick. It's useful to think of your tick methods as preparing the next world state. onTick is the first step of preparing the next state and onPostTick is the second step.

These are most useful when implementing things patterns like "camera that follows a player". If you move an entity in onTick methods, you want to wait for all of them to complete before you calculate the next camera position.

Interpolation

Dreamlab will render smooth visuals on monitors of any refresh rate. Any motion is smoothed over the appropriate amount of frames, meaning your game will take full advantage of even a 240hz monitor. This interpolation comes at the cost of 1 tick of latency.