Kategorie: Linux

Atari’s Breakout was one of the earliest video game blockbusters. Here’s how to recreate it in Python.

The original Breakout, designed by Nolan Bushnell and Steve Bristow, and famously built by a young Steve Wozniak.

Atari Breakout

The games industry owes a lot to the humble bat and ball. Designed by Allan Alcorn in 1972, Pong was a simplified version of table tennis, where the player moved a bat and scored points by ricocheting a ball past their opponent. About four years later, Atari’s Nolan Bushnell and Steve Bristow figured out a way of making Pong into a single-player game. The result was 1976’s Breakout, which rotated Pong’s action 90 degrees and replaced the second player with a wall of bricks.

Points were scored by deflecting the ball off the bat and destroying the bricks; as in Pong, the player would lose the game if the ball left the play area. Breakout was a hit for Atari, and remains one of those game ideas that has never quite faded from view; in the 1980s, Taito’s Arkanoid updated the action with collectible power-ups, multiple stages with different layouts of bricks, and enemies that disrupted the trajectory of the player’s ball.

Breakout had an impact on other genres too: game designer Tomohiro Nishikado came up with the idea for Space Invaders by switching Breakout’s bat with a base that shot bullets, while Breakout’s bricks became aliens that moved and fired back at the player.

Courtesy of Daniel Pope, here’s a simple Breakout game written in Python. To get it running on your system, you’ll first need to install Pygame Zero. And download the code for Breakout here.

Bricks and balls in Python

The code above, written by Daniel Pope, shows you just how easy it is to get a basic version of Breakout up and running in Python, using the Pygame Zero library. Like Atari’s original, this version draws a wall of blocks on the screen, sets a ball bouncing around, and gives the player a paddle, which can be controlled by moving the mouse left and right. The ball physics are simple to grasp too. The ball has a velocity, vel – which is a vector, or a pair of numbers: vx for the x direction and vy for the y direction.

The program loop checks the position of the ball and whether it’s collided with a brick or the edge of the play area. If the ball hits the left side of the play area, the ball’s x velocity vx is set to positive, thus sending it bouncing to the right. If the ball hits the right side, vx is set to a negative number, so the ball moves left. Likewise, when the ball hits the top or bottom of a brick, we set the sign of the y velocity vy, and so on for the collisions with the bat and the top of the play area and the sides of bricks. Collisions set the sign of vx and vy but never change the magnitude. This is called a perfectly elastic collision.

To this basic framework, you could add all kinds of additional features: a 2012 talk by developers Martin Jonasson and Petri Purho, which you can watch on YouTube here, shows how the Breakout concept can be given new life with the addition of a few modern design ideas.

You can read this feature and more besides in Wireframe issue 11, available now in Tesco, WHSmith, and all good independent UK newsagents.

Or you can buy Wireframe directly from us – worldwide delivery is available. And if you’d like to own a handy digital version of the magazine, you can also download a free PDF.

Make sure to follow Wireframe on Twitter and Facebook for updates and exclusives, and for subscriptions, visit the Wireframe website to save 49% compared to newsstand pricing!

Website: LINK

Rik Cross, Senior Learning Manager here at Raspberry Pi, shows you how to recreate the spawning of objects found in the balloon-bursting arcade gem Pang.

Pang: bringing balloon-hating to the masses since 1989.

Capcom’s Pang

Programmed by Mitchell and distributed by Capcom, Pang was first released as an arcade game in 1989, but was later ported to a whole host of home computers, including the ZX Spectrum, Amiga, and Commodore 64. The aim in Pang is to destroy balloons as they bounce around the screen, either alone or working together with another player, in increasingly elaborate levels. Destroying a balloon can sometimes also spawn a power-up, freezing all balloons for a short time or giving the player a better weapon with which to destroy balloons.

Initially, the player is faced with the task of destroying a small number of large balloons. However, destroying a large balloon spawns two smaller balloons, which in turn spawns two smaller balloons, and so on. Each level is only complete once all balloons have been broken up and completely destroyed. To add challenge to the game, different-sized balloons have different attributes – smaller balloons move faster and don’t bounce as high, making them more difficult to destroy.

Rik’s spawning balloons, up and running in Pygame Zero. Hit space to divide them into smaller balloons.

Spawning balloons

There are a few different ways to achieve this game mechanic, but the approach I’ll take in my example is to use various features of object orientation (as usual, my example code has been written in Python, using the Pygame Zero library). It’s also worth mentioning that for brevity, the example code only deals with simple spawning and destroying of objects, and doesn’t handle balloon movement or collision detection.

The base Enemy class is simply a subclass of Pygame Zero’s Actor class, including a static enemies list to keep track of all enemies that exist within a level. The Enemy subclass also includes a destroy() method, which removes an enemy from the enemies list and deletes the object.

There are then three further subclasses of the Enemy class, called LargeEnemy, MediumEnemy, and SmallEnemy. Each of these subclasses are instantiated with a specific image, and also include a destroy() method. This method simply calls the same destroy() method of its parent Enemy class, but additionally creates two more objects nearby — with large enemies spawning two medium enemies, and medium enemies spawning two small enemies.

Here’s Rik’s example code, which recreates Pang’s spawning balloons in Python. To get it running on your system, you’ll first need to install Pygame Zero – you can find full instructions here. And you can download the code here.

In the example code, initially two LargeEnemy objects are created, with the first object in the enemies list having its destroy() method called each time the Space key is pressed. If you run this code, you’ll see that the first large enemy is destroyed and two medium-sized enemies are created. This chain reaction of destroying and creating enemies continues until all SmallEnemy objects are destroyed (small enemies don’t create any other enemies when destroyed).

As I mentioned earlier, this isn’t the only way of achieving this behaviour, and there are advantages and disadvantages to this approach. Using subclasses for each size of enemy allows for a lot of customisation, but could get unwieldy if much more than three enemy sizes are required. One alternative is to simply have a single Enemy class, with a size attribute. The enemy’s image, the entities it creates when destroyed, and even the movement speed and bounce height could all depend on the value of the enemy size.

You can read the rest of the feature in Wireframe issue 10, available now in Tesco, WHSmith, and all good independent UK newsagents.

Or you can buy Wireframe directly from us – worldwide delivery is available. And if you’d like to own a handy digital version of the magazine, you can also download a free PDF.

Make sure to follow Wireframe on Twitter and Facebook for updates and exclusives, and for subscriptions, visit the Wireframe website to save 49% compared to newsstand pricing!

Website: LINK