import { vec2 } from "gl-matrix";
import Camera from "./camera/camera";
import Entity from "./entity";
import { System } from "./system";
import TimeStep from "./timestep";
import Fluid from "./physics/fluid/fluid";
export declare type EntityListener = (event: "add" | "remove", entity: Entity, index: number, entities: Entity[]) => void;
/**
 * Represents the 2D world.
 */
export default class World implements System {
    cellSize: vec2;
    useBatchRenderer: boolean;
    private camera;
    private entities;
    private fluids;
    /**
     * Callbacks which are fired whenever an entity is added or removed.
     */
    private entityListeners;
    /**
     * Creates a {@link World} instance.
     *
     * @param cellSize The width and height of each world cell in pixels
     * @param cameraViewport The width and height of the camera's viewport in pixels
     */
    constructor(cellSize: vec2, cameraViewport: vec2);
    /**
     * Creates a {@link World} instance with a dynamic viewport that resizes to the  {@link Renderer}'s dimensions.
     *
     * @param cellSize The width and height of each world cell in pixels
     */
    constructor(cellSize: vec2);
    /**
     * Updates the world's camera, terrain and entities.
     *
     * Also calls the render function.
     *
     * @param ts The {@link TimeStep} for this update
     */
    update(ts: TimeStep): void;
    /**
     * Renders the entities in the world using the world's current camera.
     */
    renderEntities(): void;
    /**
     * Renders the fluids in the world using the world's current camera.
     */
    renderFluids(): void;
    /**
     * Calculates the world space to clip space scale.
     *
     * @returns The number that multiplying a world space coordinate by provides the equivalent clip space coordinate.
     */
    getWorldtoClipSpace(): vec2;
    /**
     * Calculates the world space to pixel space scale.
     *
     * @returns The number that multiplying a world space coordinate by provides the equivalent pixel space coordinate.
     */
    getWorldToPixelSpace(): vec2;
    /**
     * Calculates the pixel space to world space scale.
     *
     * @returns The number that multiplying a pixel space coordinate by provides the equivalent world space coordinate.
     */
    getPixelToWorldSpace(): vec2;
    /**
     * Gets the world location of a pixel on the screen.
     *
     * This is calculated using the viewport of the world camera.
     *
     * @param pixel A pixel position on the screen
     */
    getWorldFromPixel(pixel: vec2): vec2;
    /**
     * Gets the pixel coordinate of a world location.
     *
     * This is calculated using the viewport of the world camera.
     *
     * @param world A world position
     */
    getPixelFromWorld(world: vec2): vec2;
    /**
     * Gets all entities currently in the world.
     *
     * @returns All entites in the world
     */
    getEntities(): Entity[];
    /**
     * Gets all entities with the given name.
     *
     * @param name The name of the entity
     */
    getEntitiesByName(name: string): Entity[];
    /**
     * Adds an entity to the world.
     *
     * @param entity The entity to add
     * @param fireListeners Wether or not to execute the world's entity listeners
     */
    addEntity(entity: Entity, fireListeners?: boolean): void;
    /**
     * Adds the given entities to the world.
     *
     * By default entity listeners are fired for each entity added however, if the last argument
     * passed to this function is a boolean then it will be used to decide wether or not to fire entity listeners.
     *
     * @param entities The entities to add
     */
    addEntities(...entities: (Entity | boolean)[]): void;
    /**
     * Removes an entity from the world.
     *
     * @param entity The entity to remove
     * @param fireListeners Wether or not to execute the world's entity listeners
     * @returns Wether or not the entity was removed
     */
    removeEntity(entity: Entity, fireListeners?: boolean): boolean;
    private callEntityListeners;
    /**
     * Adds a callback which will be called whenever an entity is added or removed from the world.
     *
     * @param listener The listener to add
     */
    addEntityListener(listener: EntityListener): void;
    /**
     * Removes an {@link EntityListener} from the world.
     *
     * @param listener The listener to remove
     */
    removeEntityListener(listener: EntityListener): void;
    /**
     * Adds a fluid to the world.
     *
     * @param fluid The fluid to add
     */
    addFluid(fluid: Fluid): void;
    /**
     * Removes a fluid from the world.
     *
     * @param fluid The fluid to remove
     */
    removeFluid(fluid: Fluid): void;
    /**
     * Sets the camera to use for rendering.
     *
     * @param camera The camera to use for rendering
     */
    useCamera(camera: Camera): void;
    /**
     * Gets the camera that is currently being used for rendering.
     *
     * @returns The camera that is currently being used for rendering
     */
    getCamera(): Camera;
}