Progress Report - George.md

Progress Report - George

Main.py

The main.py is a file I created which is meant to bootstrap the application. This file initiates PyGame, imports App, and starts the game. Run this file to run the game.

Originally the pygame was initialized in the App class, see the App header for more.

The App Class

PyGame itself provides very little framework. All you really need to do is call pygame.init() and start drawing to the window. For this reason I created the App class which provides a better framework and separation of logic.

The class follows the singleton pattern (i.e. there is one instance of the class that can be accessed statically) and the instance is accessed using App.instance.

The class encapsulates all the objects and logic required to run the game. When App.start() is called, PyGame is instructed to display a window and App enters the game-loop by running App.loop(). The game loop runs while App._running is set to True and it has several discrete steps:

1. Handle PyGame events
   1. The App.handle_events() method loops through the current PyGame events and dispatches appropriately.
      1. If the event is pygame.QUIT then the _running flag is set to false and the game loop exits.
      2. If the event is a keyboard event, it is passed to App.keyboard(event), and if it's a MOUSEBUTTONDOWN event, App.click(event)
2. Run game logic
   1. The App.logic() method is called, which is where all the game logic is meant to be encapsulated. If this were a live-action game then this is where the code to move physics objects would be applied.
3. Render the game: After all the events have been handled and the game logic has been run, the game needs to be drawn to the screen!
   1. The App.render() method is invoked, in this method:
      1. The screen is cleared using App.fill_color
      2. Stuff is rendered to the screen, which "stuff" will depend on the App.render_option flag. This is because the game has multiple states like the title screen, maybe a pause menu, and the game itself.
      3. We call pygame.display.flip() which applies all the rendering operations we have done to the screen

Once the loop has exited, App.cleanup() is called. This is where all necessary cleaning up operations like quitting PyGame, closing file handles, and maybe writing log data can be handled.

The Button Class

This class is my naive implementation of the classic button UI element. It's initialized with an xy position, width, height, style object, text string, and an on click (callable) handler.

How to use it

1. Instantiate an instance of Button, give it an appropriate position, width, height, etc and give it a proper on_click handler. The on_click handler can be a function or a lambda.
2. Handle clicking events. It's a button! We need to have it respond to when it's clicked. The way to do this is to call Button.handle_click(MOUSEVENT). This method takes a mouse event and determines if the click happened within its own bounds and triggers the on_click handler if necessary. I recommend you place this in App.click() and pass the mouse event.
3. Ensure that the button gets rendered. Do this by inserting a Button.render() call inside App.render(). Please ensure that the button is only being rendered if you are checking mouse events and vice versa, you can do both of these optionally.