Time

There is no clock. There is only `dt`.

Unit#

In Ignis, the unit of time and duration is seconds, always expressed as a double.

Ticks#

Nodes can hook into the game loop with tick:

// Do something every frame...
tick((double dt) {
  // `dt` seconds elapsed this frame.
  // This is usually quite small, e.g. 0.01666 at 60 FPS.
});

Anything that happens at a rate should be scaled on the way in. For example, a velocity in units per second becomes a distance when scaled by dt:

tick((double dt) {
  position.addScaled(velocity, dt);
});

Additionally, all Ignis objects that accept an interval or duration are expressed in seconds.

// Triggers after 200 milliseconds.
final timer = TimerNode(interval: 0.2);

// Progresses an effect over the course of 1.5 seconds.
final controller = EffectController.duration(1.5);