.. note::

    Hello, welcome to the SunFounder Raspberry Pi & Arduino & ESP32 Enthusiasts Community on Facebook! Dive deeper into Raspberry Pi, Arduino, and ESP32 with fellow enthusiasts.

    **Why Join?**

    - **Expert Support**: Solve post-sale issues and technical challenges with help from our community and team.
    - **Learn & Share**: Exchange tips and tutorials to enhance your skills.
    - **Exclusive Previews**: Get early access to new product announcements and sneak peeks.
    - **Special Discounts**: Enjoy exclusive discounts on our newest products.
    - **Festive Promotions and Giveaways**: Take part in giveaways and holiday promotions.

    👉 Ready to explore and create with us? Click [|link_sf_facebook|] and join today!

Hello Mouse
==================

In this project, your mouse will keep shooting lines towards a point; move the mouse and you will draw a unique line of stars. Press the mouse to restart the drawing.

.. image:: img/hello_mouse1.png

**Sketch**

.. code-block:: arduino

    int pointX = 172;
    int pointY = 88;

    void setup() {
        size(400, 400);
        stroke(255);
        background(192, 16, 18);
    }

    void draw() {
        line(pointX, pointY, mouseX, mouseY);
    }

    void mousePressed() {
        pointX=mouseX;
        pointY=mouseY;
        background(192, 16, 18);
    }

**How it works?**

The previous project was drawing a single image without any animation or interaction.

If we want to make an interactive sketch, we need to add the ``setup()`` and ``draw()`` functions (these are built-in functions that are called automatically) to build the frame.

* ``setup()``: Executed only once at the start of the sketch.
* ``draw()``: Executed repeatedly, where we usually add the sketch for drawing the animation.

.. code-block:: arduino

    int pointX = 172;
    int pointY = 88;

    void setup() {
        size(400, 400);
        stroke(255);
        background(192, 16, 18);
    }

    void draw() {
        line(pointX, pointY, mouseX, mouseY);
    }

This sketch above already works smoothly as an interactive sketch.

Next you can add a mouse click event. This event can be implemented with the ``mousePressed()`` function, where we add statements to refresh the target point and clear the screen.

.. code-block:: arduino

    int pointX = 172;
    int pointY = 88;

    void setup() {
        size(400, 400);
        stroke(255);
        background(192, 16, 18);
    }

    void draw() {
        line(pointX, pointY, mouseX, mouseY);
    }

    void mousePressed() {
        pointX=mouseX;
        pointY=mouseY;
        background(192, 16, 18);
    }


For more please refer to `Processing Reference <https://processing.org/reference/>`_.