PyBreak

A block breaking game based on Python!

Requirements

• Python3

• Python Libarary Pillow If you haven't installed yet, try this in a Terminal: pip install Pillow

Usage

Run pybreak.py in a Terminal

Run a demo for all of block types:

python3 pybreak.py

Or select a stage by a command line argument such as:

python3 pybreak.py stage1

Description

Game Control System

class Game

game = Game(stage, width=600, height=480, dt=10)

creates a Game object game based on the given stage.

• game.objects A dictionary maps string of class name to list of corresponding objects, for all subclasses of GameObject.

keys	values
'GameObject'	[<Ball instance>, <Paddle instance>, <Block instance>, ...]
'Ball'	[<Ball instance>, ...]
'Paddle'	[<Paddle instance>]
'Block'	[<Block instance>, <HardBlock instance>, ...]
...	...

• game.start() Will start to run the game, which calls obj.update() every dt milliseconds for any obj where obj is a GameObject object and belongs to game.

class GameObject

All objects used for the game should be a instance of GameObject. However, the GameObject class is not supposed to be instanciated directly. Instead, use a subclass of GameObject with a constructor of:

__init__(self, game, *args, **kwargs)

This will make sure that the given game object knows this new object belongs to itself.

class Stage

NOTE: Instead of instanciating Stage objects, it's better to use files, which will be described next.

__init__(self, name, m, n, blocks)

• name The name of the stage. Will be displayed in the title of the window.
• m The number of rows of blocks.
• n The number of cols of blocks.
• blocks A list of lists of block classes in a row.

Files for Stage

• In the directory config, there is a file named block_type, which maps symbols to subclasses of Block in a format of

  {symbol}: {class_name}

• In the directory stage, every file defines a stage with

  • its file name as stage.name, which is also the command line argument for stage selection
  • first line consists of 2 integers as stage.m and stage.n, respectively
  • remaining lines as stage.blocks using symbols defined in block_type mentioned above.

• Take a look at existing files for an example.

Physics Engine

Collision Detection

AABB - Circle collision detection from here by Joey de Vries .

Perfect Elastic Collision

Elastic collision

Blocks

class Block

A basic Block. Nothing special.

• Will be rendered using a png image stored in the directory image with a file name of {class_name}.png. If not exists for a subclass, using Block.png instead.

• __init__(self, game, x, y, wx, wy) Creates a Block object with center at (x, y), half x-span of wx, and half y-span of wy. Should be called explicitly if a subclass overrides it.

• self.duration = 1 indicates the necessary number of hits by a ball to destory it.

• apply_effect(self, ball) will be called whenever a collision with a ball happens. Override this in subclasses to customize its behavior.

class HardBlock

A HardBlock. Needs 2 hits to destory.

• Has a total duration of 2.
• Cracks when first hit.

class SplitBlock

A SplitBlock. Splits the ball.

• If hit by a ball, makes it to split into 2.

class ExtendBlock

An ExtendBlock. Extends the paddle.

• If hit by a ball, extends the paddle by 50%.

class ShortenBlock

A ShortenBlock. Shortens the paddle.

• If hit by a ball, shortens the paddle by 1/3.

class SpeedUpBlock

A SpeedUpBlock. Speeds up the ball.

• If hit by a ball, speeds it up by 50%.

class SlowDownBlock

A SlowDownBlock. Slows down the ball.

• If hit by a ball, slows it down by 1/3.