Detector

import { Detector } from "encompass-ecs";

A Detector is a subclass of Engine that provides a structure for a common pattern - performing a task for each Entity which has a particular combination of Components.

Detectors are defined by the Component types they track and the detect function they implement.

Abstracts

Type<Component>[] component_types

The Component types that will cause the Entity to be tracked by the Detector. Define using @Detects decorator.

detect(entity, dt)

This callback is triggered every frame when an Entity has all the required component types specified by the component_types property.

Arguments:

• entity (Entity) – An entity that is being tracked by the Detector.
• dt (number) – Delta time.

Example

import { Detector, Entity } from "encompass-ecs";

import { PositionComponent } from "src/components/position";
import { VelocityComponent } from "src/components/velocity";
import { MotionMessage } from "src/messages/motion";

@Detects(PositionComponent, VelocityComponent)
@Emits(MotionMessage)
class MotionDetector extends Detector {
    protected detect(entity: Entity) {
        const position_component = entity.get_component(PositionComponent);
        const velocity_component = entity.get_component(VelocityComponent);

        const motion_message = this.create_component_message(MotionMessage, position_component);
        motion_message.x_delta = velocity_component.x;
        motion_message.y_delta = velocity_component.y;
    }
}