Part 1 - Drawing the '@' symbol
===============================

Code
----

Write the following code into the ``main.py`` file:

.. code::

    import sdl2.ext
    from sdl2 import SDL_Color


    sdl2.ext.init()

    screen_width = 640
    screen_height = 480

    window = sdl2.ext.Window(
        "PySDL2 Roguelike Tutorial", size=(screen_width, screen_height)
    )
    window.show()

    renderer = sdl2.ext.Renderer(window)

    fg = SDL_Color(255, 255, 255)
    bg = SDL_Color(0, 0, 0)

    font_manager = sdl2.ext.FontManager(
        font_path="C:\\Windows\\Fonts\\arial.ttf", size=16, color=fg, bg_color=bg
    )

    factory = sdl2.ext.SpriteFactory(renderer=renderer)
    
    text = factory.from_text("@", fontmanager=font_manager)

    x_offset = screen_width // 2 - text.size[0] // 2
    y_offset = screen_height // 2 - text.size[1] // 2
    renderer.copy(text, dstrect=(x_offset, y_offset, text.size[0], text.size[1]))

    renderer.present()

    processor = sdl2.ext.TestEventProcessor()
    processor.run(window)

    sdl2.ext.quit()


Run the code using ``python main.py`` and you will see the following picture

.. image:: _images/part01_1.png

Explanation
------------

Importing PySDL2 library

.. code::

    import sdl2.ext
    from sdl2 import SDL_Color

Setting the resolution of the window

.. code::

    screen_width = 640
    screen_height = 480

Creating a window with a title and a specific size

.. code::

    window = sdl2.ext.Window(
        "PySDL2 Roguelike Tutorial", size=(screen_width, screen_height)
    )
    window.show()

Create a renderer from the window variable

.. code::

    renderer = sdl2.ext.Renderer(window)

Foreground and background colors that will be used for outputting the character

.. code::

    fg = SDL_Color(255, 255, 255)
    bg = SDL_Color(0, 0, 0)

Create a font manager with specific font and font size to be used in text outputting

.. code::

    font_manager = sdl2.ext.FontManager(
        font_path="C:\\Windows\\Fonts\\arial.ttf", size=16, color=fg, bg_color=bg
    )

Create a sprite factory to then create a sprite from text

.. code::

    factory = sdl2.ext.SpriteFactory(renderer=renderer)
    
Create a sprite from text using a sprite factory

.. code::

    text = factory.from_text("@", fontmanager=font_manager)

Calculate the top left corner of the text to output

.. code::

    x_offset = screen_width // 2 - text.size[0] // 2
    y_offset = screen_height // 2 - text.size[1] // 2

Output the text in a window

.. code::

    renderer.copy(text, dstrect=(x_offset, y_offset, text.size[0], text.size[1]))

Here all changes that were previously made will become visible. SDL2 first saves the changes that should be made to the screen and then with this command shows the changes

.. code::

    renderer.present()

Process the events so that the windows does not freeze and waits for it to be closed

.. code::

    processor = sdl2.ext.TestEventProcessor()
    processor.run(window)

Clean up everything, once the application finishes

.. code::

    sdl2.ext.quit()