/DXBallGame

Primary LanguageC++

Notes post refactor April 2024

The codebase has been brought in-line with modern cpp convention and is far more ogranised in terms of its file structure, declaration patterns and slioing of functionality.

There are some major areas of improvement which have been identified and should be much easier to reason about now:

  • Many functions implicitly access and mutate global state, this should be rectified prior to anything else as it is generally very bad practice and makes the codebase far more difficult to reason about. Any and all mutable data scoped to a function should be done so explicitly.
  • Many antipatterns currently exist where one routine refers to and mutates both the abstract state of the game AND informs / executes rendering functionality, these should be completely decoupled.

ie. end_game() should only be responsible for updating the game state to reflect the game ending (it should also accept the game state as an argument), and not also be responsible for rendering the game over screen (or drawing anything).

  • Some fun stuff could be the redesign of level generation patterns to be a function of gamestate values rather than static function per level etc.

/- Oscar Harris <T1 2024>

Documentation on Splashkit's Brick Breaker/Breakout game - 'DX game'

Members Roles
Swanny Aurellia Code
Norman Spencer Harty Code
Tulsi Balamurali Documentation: Purpose and steps involved, Raspberry Pi testing
Harney Halls Documentation: Introduction and Details of game, Game sprites

Introduction

The team has decided to create a clone of the games 'DX' and 'Breakout', by using C++ and Splashkit to demonstrate the capapbilities available to splashkit. Swanny and Norman have been the coder's behind the game, while Tulsi has worked on the documentation and testing the game on rapsberry Pi, and Harney have worked on both documentation and the game sprites. The game is made to assist future students in developing games and understanding the fundamentals of C++ and the coding language with Splashkit. The game is also made to test splashkit's capabilities with Raspberry Pi and arcade style games thanks to the work of Tulsi. DXball/Breakout is one of two new products being developed, alongside the Asteroid's game done by Phil Williams, Riley Michael and Ro Wern Ong.

Purpose of the game

This application/game is designed to demonstrate and explore the capabilities of SplashKit, an open-source Software Development Kit (SDK) created with the purpose of reducing the overhead required for truly technical coding.

SplashKit is primarily used for coding 2D games with unrestricted creativity and have a grounded knowledge of C++. To show the efficiency and working of this software we have decided to create a DX Ball Game, also known as Breakout, which is an arcade video game designed to be played on arcade machines and raspberry pi-based units. The functionality of the game can also be later extended to other gaming platforms like mobiles, PCs and console environments and is open for interpretation of future developers.

Steps involved in making the game

Programming Language

The programming language we have chosen is C++ and an open source like SplashKit. Main reason for the team to choose C++ because some members had more experience in the language. This language was used in SIT102 Introduction to Programming, which also made use of SplashKit.

C++ was chosen because it has imperative, object-oriented, and generic programming features and runs on various platforms like Windows, Linux, Unix, Mac, etc. C++ is an object-oriented programming language, which is a collection of commands instructing the computer with C++ ASCII text files. The language can support unions and structures that are a mix of stand-alone and put-together files. C++ programs are useful for low-level programming language and efficient for general purposes. They offer performance, memory efficiency, and high-level abstraction, within the language of the matter domain.

Two major problems in C++ is complex during a very large high-level program, C++ is employed for platform-specific application and commonly, for the actual OS or platform, the library set is typically chosen. C++ program is complex during a very large high-level program, C++ is employed for platform-specific application commonly, For the actual OS or platform, the library set is typically chosen.

Despite the disadvantages, the main reason for the team to choose C++ because some members had more experience in the language. This language was used in SIT102 Introduction to Programming, which also made use of SplashKit. Since the team had a clear language preference, C++ was chosen as the way to go.

Software Used

We also use GitHub to store and share our work within the team. GitHub is a platform used to manage open-source projects. It is free to use for open-source projects and includes a wiki and issue tracker.

Microsoft Teams was used to communicate within the team members and used to share various documentation and data regarding the project. It was also used to communicate with fellow company members and the company staff.

Description of the game

The brick breakout game is a simple game where the player must destroy bricks of a wall in order to proceed to the next level. The game is based off of the games Break out, and DX-ball, as shown below. DX-Ball. The game would have an opening screen that would allow the player to begin the game, including the name of the game, Thoth Tech company, and Splashkit. The game would run by allowing the player to move the platform left or right, or the x axis. The ball bounces between the walls and the bricks, and the platform. The goal is to break all the bricks on screen without the ball falling to the floor. The player would need to ensure the ball is able to be deflected off of the platform each time it returns. Once the ball hits the floor (past the platform), the player would be met with a game over screen.

Environment

The software involved are the MSYS terminal to compile and run SplashKit games and a code editor such as Visual Studio to write the code. MSYS2 is software distribution and a building platform for Windows. It provides a Unix-like environment, a command-line interface and a software repository making it easier to install, use, build and port software on Windows. It is an independent rewrite of MSYS, based on modern Cygwin (POSIX compatibility layer) and MinGW-w64 with the aim of better interoperability with native Windows software.

We have used basic shapes like circle for the ball and rectangle for the blocks and paddle for the initial development of the game. We replaced these basic structures with sprites for bettering the cosmetics and the aesthetics of the game. Sprites are created using basic software like MS Paint.

The draw_blocks function in the code was made to help drawing all the blocks to the environment. This function is mainly used to take an array of blocks and iterate it to draw each block on the scene. If a particular block has been broken, it will not be drawn to the environment.

Types of Bricks

Currently, three different types of bricks are being used in the game.

  1. Single Collision Bricks: These bricks can be destroyed when collides with the ball once. These bricks have the easiest difficulty to score with.
  2. Dual Collision Bricks: These bricks can be destroyed after colliding with the ball twice. They have been designed to offer the player medium difficulty to clear the level with.
  3. Hidden Blocks: These blocks are invisible to the player on the first playthrough. These blocks become visible once the ball comes in contact with the brick. Although, these blocks are quite easier to clear with as they can be broken on the second playthrough basically becoming a single collision brick.

Controls of the game

Controlling the player movement: The function that is being used to control players is process_events(). The key part of the function is to allow SplashKit to react to user input e.g., keyboard presses.

The controls on PC, for the actual gameplay are:

  • Left Arrow – Move the paddle to the left.
  • Right Arrow – Move the paddle to the right.

The controls on PC for the user interface elements are:

  • Left Arrow – Swap between the initials being selected during high score nickname input.
  • Right Arrow – Swap between the initials being selected during high score nickname input.
  • Up Arrow – Swap to the next letter when inputting initials for high score nickname.
  • Down Arrow – Swap to the previous letter when inputting initials for high score nickname.
  • Left Control - When the user interface asks for you to press 1, it is waiting/checking for 'Left Control'.
  • Left Alt - When the user interface asks for you to press 2, it is waiting/checking for 'Left Alt'.
  • '1' Key - When the user interface asks for you to press Start, it is waiting/checking for the number '1'.

Controlling the ball movement: The structure that is used to control ball movement is ball_data that contains the direction of the ball. The variable bool_up decides if the ball moves upwards or downwards on the y axis, while bool_right decides if the ball moves towards the left or right on the x axis. For example, if bool_up and bool_right is true, the ball is moving diagonally upwards towards the right side.

Continuous Ball Movement until stoppage: The ball follows the laws of physics and to the other direction when colliding with the walls and bricks. The collision is detected by evaluating the ball location. When the edges of the ball is at the location of the edges of the walls or the blocks, the ball will bounce. This functionality is included under the function check_ball_collision.

End the game if out of scope: When the ball hits the ground, the ball is removed. If there is no more presence of the ball in the game, the game state variables are set to: game_over = true, game_won = false. This will show a text saying Game Over.

Scoring in the game

  1. Sensing the breakage of the brick: The brick_data structure contains the brick's hit point. Each time the brick collides with a ball, the value of the hit point is reduced. When the value hits 0, the brick is broken and score is added.

  2. Calculating scores in the game: The scoring system is Ax1 point added to the score when a brick is broken, where A is the amount of the points accumulated by the player until that point in the game. Each time a block is broken, the score is increased by one unit. When the ball finally goes out of scope, the final value on A is displayed.

  3. Proceeding to the next level: The remaining_blocks variable determines how many bricks are left in the game. It has a predefined value pertaining to that level depending on the number of blocks in the level. Once it reaches zero, the Boolean variable next_level becomes true and the function to spawn the next level is called.

Powerups

  1. Multiple Balls – Based on the score limiter, multiple balls can be generated to break the blocks much more effectively and easily.
  2. Score Multipliers - Temporarily multiplies all score gain by the stated value of the multiplier.

Levels

We currently have four levels that each introduce a new gameplay mechanic, which are the different types of bricks in this case.

  1. Level 1 introduce basic gameplay with single collision bricks and making thee player familiar with the existing gameplay.
  2. Level 2 is updated with dual collision blocks to entertain the player with moderate difficulty leading to the next level.
  3. Level 3 introduces hidden blocks to show and test the player’s capabilities that has been earned so far in the game.
  4. Level 4 combines everything we had tested the player for. We will have a combination of all the different types of bricks and players will be encouraged to use the powerups in order to clear the level.

The goal of the four levels is to showcase the game we have built so far. It combines all the gameplay mechanics and items to demonstrate the work that we have been involved so far. Future teams can add more levels with increasing difficulties whilst also giving players more powerups and scoring opportunities.

Originally, the idea was decided between 10 set levels, or the ability to have infinite levels with chances of repetative levels. The idea was chosen for, at the time, 10 levels to be included. It was then changed to 4 levels, as there was nothing new to be introduced after level 4.

Future ideas for the game can include lives of the player (standard of 3 lives), with the chance to gain more lives through powerups. Different powerups, such as a larger ball, or smaller platform, or 'bombs' to explode large chunks of bricks. There can also be disadvantages to the player too, such as the smaller platform, lose a life or others.

Sprites of the game (Harney)

Sprites include:

  • Different coloured blocks/bricks.
  • multiplier score (x2, x3, x4, x5) gauge.
  • power ups (transparent images drop down).
  • Platform.
  • ball/s.
  • Score text
  • Multiplier text