declare namespace pc {

    /**
     * @component
     * @name pc.CameraComponent
     * @extends pc.Component
     * @class The Camera Component enables an Entity to render the scene. A scene requires at least one
     * enabled camera component to be rendered. Note that multiple camera components can be enabled
     * simultaneously (for split-screen or offscreen rendering, for example).
     * @description Create a new Camera Component.
     * @param {pc.CameraComponentSystem} system The ComponentSystem that created this Component.
     * @param {pc.Entity} entity The Entity that this Component is attached to.
     * @example
     * // Add a pc.CameraComponent to an entity
     * var entity = new pc.Entity();
     * entity.addComponent('camera', {
     *     nearClip: 1,
     *     farClip: 100,
     *     fov: 55
     * });
     * @example
     * // Get the pc.CameraComponent on an entity
     * var cameraComponent = entity.camera;
     * @example
     * // Update a property on a camera component
     * entity.camera.nearClip = 2;
     * @property {Number} projection The type of projection used to render the camera. Can be:
     * <ul>
     *     <li>{@link pc.PROJECTION_PERSPECTIVE}: A perspective projection. The camera frustum resembles a truncated pyramid.</li>
     *     <li>{@link pc.PROJECTION_ORTHOGRAPHIC}: An orthographic projection. The camera frustum is a cuboid.</li>
     * </ul>
     * Defaults to pc.PROJECTION_PERSPECTIVE.
     * @property {Number} nearClip The distance from the camera before which no rendering will take place.
     * @property {Number} farClip The distance from the camera after which no rendering will take place.
     * @property {Number} aspectRatio The aspect ratio of the camera. This is the ratio of width divided by height. Default to 16/9.
     * @property {Boolean} horizontalFov Set which axis to use for the Field of View calculation. Defaults to false (use Y-axis).
     * @property {Number} fov The field of view of the camera in degrees. Usually this is the Y-axis field of
     * view, see {@link pc.CameraComponent#horizontalFov}. Used for {@link pc.PROJECTION_PERSPECTIVE} cameras only. Defaults to 45.
     * @property {Number} orthoHeight The half-height of the orthographic view window (in the Y-axis). Used for
     * {@link pc.PROJECTION_ORTHOGRAPHIC} cameras only. Defaults to 10.
     * @property {Number} priority Controls the order in which cameras are rendered. Cameras with smaller values for priority are rendered first.
     * @property {pc.Color} clearColor The color used to clear the canvas to before the camera starts to render.
     * @property {Boolean} clearColorBuffer If true the camera will clear the color buffer to the color set in clearColor.
     * @property {Boolean} clearDepthBuffer If true the camera will clear the depth buffer.
     * @property {Boolean} clearStencilBuffer If true the camera will clear the stencil buffer.
     * @property {pc.Vec4} rect Controls where on the screen the camera will be rendered in normalized screen coordinates.
     * @property {pc.Vec4} scissorRect Clips all pixels which are not in the rectangle.
     * The order of the values is [x, y, width, height].
     * @property {pc.RenderTarget} renderTarget The render target of the camera. Defaults to null, which causes
     * the camera to render to the canvas' back buffer. Setting a valid render target effectively causes the camera
     * to render to an offscreen buffer, which can then be used to achieve certain graphics effect (normally post
     * effects).
     * @property {pc.PostEffectQueue} postEffects The post effects queue for this camera. Use this to add or remove post effects from the camera.
     * @property {Boolean} frustumCulling Controls the culling of mesh instances against the camera frustum. If true, culling is enabled.
     * If false, all mesh instances in the scene are rendered by the camera, regardless of visibility. Defaults to false.
     * @property {Function} calculateTransform Custom function you can provide to calculate the camera transformation matrix manually. Can be used for complex effects like reflections. Function is called using component's scope.
     * Arguments:
     *     <li>{pc.Mat4} transformMatrix: output of the function</li>
     *     <li>{Number} view: Type of view. Can be pc.VIEW_CENTER, pc.VIEW_LEFT or pc.VIEW_RIGHT. Left and right are only used in stereo rendering.</li>
     * @property {Function} calculateProjection Custom function you can provide to calculate the camera projection matrix manually. Can be used for complex effects like doing oblique projection. Function is called using component's scope.
     * Arguments:
     *     <li>{pc.Mat4} transformMatrix: output of the function</li>
     *     <li>{Number} view: Type of view. Can be pc.VIEW_CENTER, pc.VIEW_LEFT or pc.VIEW_RIGHT. Left and right are only used in stereo rendering.</li>
     * @property {Boolean} cullFaces If true the camera will take material.cull into account. Otherwise both front and back faces will be rendered.
     * @property {Boolean} flipFaces If true the camera will invert front and back faces. Can be useful for reflection rendering.
     */
    class CameraComponent extends pc.Component {
        constructor(system: pc.CameraComponentSystem, entity: pc.Entity)

        projection: number;
        nearClip: number;
        farClip: number;
        aspectRatio: number;
        horizontalFov: boolean;
        fov: number;
        orthoHeight: number;
        priority: number;
        clearColor: pc.Color;
        clearColorBuffer: boolean;
        clearDepthBuffer: boolean;
        clearStencilBuffer: boolean;
        rect: pc.Vec4;
        scissorRect: pc.Vec4;
        renderTarget: pc.RenderTarget;
        postEffects: pc.PostEffectQueue;
        frustumCulling: boolean;
        calculateTransform: Function;
        calculateProjection: Function;
        cullFaces: boolean;
        flipFaces: boolean;

        /**
         * @readonly
         * @name pc.CameraComponent#projectionMatrix
         * @type pc.Mat4
         * @description Queries the camera's projection matrix.
         */
        readonly projectionMatrix: pc.Mat4;

        /**
         * @readonly
         * @name pc.CameraComponent#viewMatrix
         * @type pc.Mat4
         * @description Queries the camera's view matrix.
         */
        readonly viewMatrix: pc.Mat4;

        /**
         * @readonly
         * @name pc.CameraComponent#frustum
         * @type pc.Frustum
         * @description Queries the camera's frustum shape.
         */
        readonly frustum: pc.Frustum;

        /**
         * @name pc.CameraComponent#vrDisplay
         * @type pc.VrDisplay
         * @description The {@link pc.VrDisplay} that the camera is current displaying to. This is set automatically by calls to {@link pc.CameraComponent#enterVr}
         * or {@link pc.CameraComponent#exitVr}. Setting this property to a display directly enables the camera to use the transformation information
         * from a display without rendering stereo to it, e.g. for "magic window" style experiences.
         * @example
         * // enable magic window style interface
         * var display = this.app.vr.display;
         * if (display) {
         *     this.entity.camera.vrDisplay = display;
         * }
         *
         * var camera = this.entity.camera;
         * camera.enterVr(function (err) {
         * if (err) { return; }
         *     var display = camera.vrDisplay; // access presenting pc.VrDisplay
         * });
         */
        vrDisplay: pc.VrDisplay;

        /**
         * @readonly
         * @name pc.CameraComponent#node
         * @type pc.GraphNode
         * @description Queries the camera's GraphNode. Can be used to get position and rotation.
         */
        readonly node: pc.GraphNode

        /**
         * @function
         * @name pc.CameraComponent#screenToWorld
         * @description Convert a point from 2D screen space to 3D world space.
         * @param {Number} screenx x coordinate on PlayCanvas' canvas element.
         * @param {Number} screeny y coordinate on PlayCanvas' canvas element.
         * @param {Number} cameraz The distance from the camera in world space to create the new point.
         * @param {pc.Vec3} [worldCoord] 3D vector to receive world coordinate result.
         * @example
         * // Get the start and end points of a 3D ray fired from a screen click position
         * var start = entity.camera.screenToWorld(clickX, clickY, entity.camera.nearClip);
         * var end = entity.camera.screenToWorld(clickX, clickY, entity.camera.farClip);
         *
         * // Use the ray coordinates to perform a raycast
         * app.systems.rigidbody.raycastFirst(start, end, function (result) {
         *     console.log("Entity " + result.entity.name + " was selected");
         * });
         * @returns {pc.Vec3} The world space coordinate.
         */
        screenToWorld(screenx: number, screeny: number, cameraz: number, worldCoord?: pc.Vec3): pc.Vec3;

        /**
         * @function
         * @name pc.CameraComponent#worldToScreen
         * @description Convert a point from 3D world space to 2D screen space.
         * @param {pc.Vec3} worldCoord The world space coordinate.
         * @param {pc.Vec3} [screenCoord] 3D vector to receive screen coordinate result.
         * @returns {pc.Vec3} The screen space coordinate.
         */
        worldToScreen(worldCoord: pc.Vec3, screenCoord: pc.Vec3): pc.Vec3;

        /**
         * @function
         * @private
         * @name pc.CameraComponent#frameBegin
         * @description Start rendering the frame for this camera.
         */
        private frameBegin(): void;

        /**
         * @private
         * @function
         * @name pc.CameraComponent#frameEnd
         * @description End rendering the frame for this camera
         */
        private frameEnd(): void;


        /**
         * @function
         * @name pc.CameraComponent#enterVr
         * @description Attempt to start presenting this camera to a {@link pc.VrDisplay}.
         * @param {pc.VrDisplay} [display] The VrDisplay to present. If not supplied this uses {@link pc.VrManager#display} as the default
         * @param {Function} callback Function called once to indicate success of failure. The callback takes one argument (err).
         * On success it returns null on failure it returns the error message.
         * @example
         * // On an entity with a camera component
         * this.entity.camera.enterVr(function (err) {
         *     if (err) {
         *         console.error(err);
         *         return;
         *     } else {
         *         // in VR!
         *     }
         * });
         */
        enterVr(display: pc.VrDisplay, callback: Function): void;

        /**
         * @function
         * @name pc.CameraComponent#exitVr
         * @description Attempt to stop presenting this camera.
         * @param {Function} callback Function called once to indicate success of failure. The callback takes one argument (err).
         * On success it returns null on failure it returns the error message.
         * @example
         * this.entity.camera.exitVr(function (err) {
         *     if (err) {
         *         console.error(err);
         *     } else {
         *
         *     }
         * });
         */
        exitVr(callback: Function): void;
    }
}