Babylon.js/src/Cameras/Inputs/freeCameraMouseWheelInput.ts

import { Nullable } from "../../types";
import { serialize } from "../../Misc/decorators";
import { FreeCamera } from "../../Cameras/freeCamera";
import { CameraInputTypes } from "../../Cameras/cameraInputsManager";
import { BaseCameraMouseWheelInput } from "../../Cameras/Inputs/BaseCameraMouseWheelInput";
import { Matrix, Vector3 } from "../../Maths/math.vector";

/**
 * Defines the potential axis to be altered in a transform operation.
 */
export enum AXIS {
    /**
     * X axis.
     */
    X,
    /**
     * Y axis.
     */
    Y,
    /**
     * Z axis.
     */
    Z
}

/**
 * Manage the mouse wheel inputs to control a free camera.
 * @see https://doc.babylonjs.com/how_to/customizing_camera_inputs
 */
export class FreeCameraMouseWheelInput extends BaseCameraMouseWheelInput {

    /**
     * Defines the camera the input is attached to.
     */
    public camera: FreeCamera;

    /**
     * Gets the class name of the current input.
     * @returns the class name
     */
    public getClassName(): string {
        return "FreeCameraMouseWheelInput";
    }

    /**
     * Set which movement axis (relative to camera's orientation) the mouse
     * wheel's X axis controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelXMoveRelative(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelXAction !== this._moveRelative) {
            // Attempting to clear different _wheelXAction.
            return;
        }
        this._wheelXAction = this._moveRelative;
        this._wheelXActionProperty = axis;
    }

    /**
     * Get the configured movement axis (relative to camera's orientation) the
     * mouse wheel's X axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelXMoveRelative(): Nullable<AXIS> {
        if (this._wheelXAction !== this._moveRelative) {
            return null;
        }
        return this._wheelXActionProperty;
    }

    /**
     * Set which movement axis (relative to camera's orientation) the mouse
     * wheel's Y axis controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelYMoveRelative(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelYAction !== this._moveRelative) {
            // Attempting to clear different _wheelYAction.
            return;
        }
        this._wheelYAction = this._moveRelative;
        this._wheelYActionProperty = axis;
    }

    /**
     * Get the configured movement axis (relative to camera's orientation) the
     * mouse wheel's Y axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelYMoveRelative(): Nullable<AXIS> {
        if (this._wheelYAction !== this._moveRelative) {
            return null;
        }
        return this._wheelYActionProperty;
    }

    /**
     * Set which movement axis (relative to camera's orientation) the mouse
     * wheel's Z axis controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelZMoveRelative(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelZAction !== this._moveRelative) {
            // Attempting to clear different _wheelZAction.
            return;
        }
        this._wheelZAction = this._moveRelative;
        this._wheelZActionProperty = axis;
    }

    /**
     * Get the configured movement axis (relative to camera's orientation) the
     * mouse wheel's Z axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelZMoveRelative(): Nullable<AXIS> {
        if (this._wheelZAction !== this._moveRelative) {
            return null;
        }
        return this._wheelZActionProperty;
    }

    /**
     * Set which rotation axis (relative to camera's orientation) the mouse
     * wheel's X axis controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelXRotateRelative(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelXAction !== this._rotateRelative) {
            // Attempting to clear different _wheelXAction.
            return;
        }
        this._wheelXAction = this._rotateRelative;
        this._wheelXActionProperty = axis;
    }

    /**
     * Get the configured rotation axis (relative to camera's orientation) the
     * mouse wheel's X axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelXRotateRelative(): Nullable<AXIS> {
        if (this._wheelXAction !== this._rotateRelative) {
            return null;
        }
        return this._wheelXActionProperty;
    }

    /**
     * Set which rotation axis (relative to camera's orientation) the mouse
     * wheel's Y axis controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelYRotateRelative(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelYAction !== this._rotateRelative) {
            // Attempting to clear different _wheelYAction.
            return;
        }
        this._wheelYAction = this._rotateRelative;
        this._wheelYActionProperty = axis;
    }

    /**
     * Get the configured rotation axis (relative to camera's orientation) the
     * mouse wheel's Y axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelYRotateRelative(): Nullable<AXIS> {
        if (this._wheelYAction !== this._rotateRelative) {
            return null;
        }
        return this._wheelYActionProperty;
    }

    /**
     * Set which rotation axis (relative to camera's orientation) the mouse
     * wheel's Z axis controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelZRotateRelative(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelZAction !== this._rotateRelative) {
            // Attempting to clear different _wheelZAction.
            return;
        }
        this._wheelZAction = this._rotateRelative;
        this._wheelZActionProperty = axis;
    }

    /**
     * Get the configured rotation axis (relative to camera's orientation) the
     * mouse wheel's Z axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelZRotateRelative(): Nullable<AXIS> {
        if (this._wheelZAction !== this._rotateRelative) {
            return null;
        }
        return this._wheelZActionProperty;
    }

    /**
     * Set which movement axis (relative to the scene) the mouse wheel's X axis
     * controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelXMoveScene(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelXAction !== this._rotateRelative) {
            // Attempting to clear different _wheelXAction.
            return;
        }
        this._wheelXAction = this._moveScene;
        this._wheelXActionProperty = axis;
    }

    /**
     * Get the configured movement axis (relative to the scene) the mouse wheel's
     * X axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelXMoveScene(): Nullable<AXIS> {
        if (this._wheelXAction !== this._moveScene) {
            return null;
        }
        return this._wheelXActionProperty;
    }

    /**
     * Set which movement axis (relative to the scene) the mouse wheel's Y axis
     * controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelYMoveScene(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelYAction !== this._rotateRelative) {
            // Attempting to clear different _wheelYAction.
            return;
        }
        this._wheelYAction = this._moveScene;
        this._wheelYActionProperty = axis;
    }

    /**
     * Get the configured movement axis (relative to the scene) the mouse wheel's
     * Y axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelYMoveScene(): Nullable<AXIS> {
        if (this._wheelYAction !== this._moveScene) {
            return null;
        }
        return this._wheelYActionProperty;
    }

    /**
     * Set which movement axis (relative to the scene) the mouse wheel's Z axis
     * controls.
     * @param axis The axis to be moved. Set null to clear.
     */
    @serialize()
    public set wheelZMoveScene(axis: Nullable<AXIS>) {
        if (axis === null && this._wheelZAction !== this._rotateRelative) {
            // Attempting to clear different _wheelZAction.
            return;
        }
        this._wheelZAction = this._moveScene;
        this._wheelZActionProperty = axis;
    }

    /**
     * Get the configured movement axis (relative to the scene) the mouse wheel's
     * Z axis controls.
     * @returns The configured axis or null if none.
     */
    public get wheelZMoveScene(): Nullable<AXIS> {
        if (this._wheelZAction !== this._moveScene) {
            return null;
        }
        return this._wheelZActionProperty;
    }

    /**
     * Called for each rendered frame.
     */
    public checkInputs(): void {
        if (this._wheelDeltaX === 0 &&
                this._wheelDeltaY === 0 &&
                this._wheelDeltaZ == 0) {
            return;
        }

        this._moveRelative.setAll(0);
        this._rotateRelative.setAll(0);
        this._moveScene.setAll(0);

        this._updateCamera(this._wheelDeltaX, this._wheelXAction, this._wheelXActionProperty);
        this._updateCamera(this._wheelDeltaY, this._wheelYAction, this._wheelYActionProperty);
        this._updateCamera(this._wheelDeltaZ, this._wheelZAction, this._wheelZActionProperty);

        if (this.camera.getScene().useRightHandedSystem) {
            // TODO: Does this need done for worldUpdate too?
            this._moveRelative.z *= -1;
        }

        // Convert updates relative to camera to world position update.
        const cameraTransformMatrix = Matrix.Zero();
        this.camera.getViewMatrix().invertToRef(cameraTransformMatrix);

        const transformedDirection = Vector3.Zero();
        Vector3.TransformNormalToRef(
            this._moveRelative, cameraTransformMatrix, transformedDirection);

        // Apply updates to camera position.
        this.camera.cameraRotation.x += this._rotateRelative.x / 200;
        this.camera.cameraRotation.y += this._rotateRelative.y / 200;
        this.camera.cameraDirection.addInPlace(transformedDirection);
        this.camera.cameraDirection.addInPlace(this._moveScene);

        // Call the base class implementation to handle observers and do cleanup.
        super.checkInputs();
    }

    private _moveRelative = Vector3.Zero();
    private _rotateRelative = Vector3.Zero();
    private _moveScene = Vector3.Zero();

    /**
     * These are set to the desired default behaviour.
     */
    private _wheelXAction: Nullable<Vector3> = this._moveRelative;
    private _wheelXActionProperty: Nullable<AXIS> = AXIS.X;
    private _wheelYAction: Nullable<Vector3> = this._moveRelative;
    private _wheelYActionProperty: Nullable<AXIS> = AXIS.Z;
    private _wheelZAction: Nullable<Vector3> = null;
    private _wheelZActionProperty: Nullable<AXIS> = null;

    /**
     * Called once per mouse wheel axis. Will update the camera according to any
     * configured properties for that axis.
     */
    private _updateCamera(
        value: number, action: Nullable<Vector3>, property: Nullable<Axis>): void {
            if (value === 0) {
                // Mouse wheel has not moved.
                return;
            }
            if (action === null || property === null) {
                // Mouse wheel axis not configured.
                return;
            }

            switch (property) {
                case AXIS.X:
                    action.set(value, 0, 0);
                    break;
                case AXIS.Y:
                    action.set(0, value, 0);
                    break;
                case AXIS.Z:
                    action.set(0, 0, value);
                    break;
            }
    }

}

(<any>CameraInputTypes)["FreeCameraMouseWheelInput"] = FreeCameraMouseWheelInput;