Linux Terminal Game

Code created during recording the Linux Terminal Game from Scratch video series.

Videos

Linux Terminal Game from Scratch I - Termios, ANSI Escape Codes

Linux Terminal Game from Scratch II - Game Loop, Rendering, Level Loading

Linux Terminal Game from Scratch III - Gameplay

Linux Terminal Game from Scratch IV - Tests, Rendering, Colors, Animations

Requirements

Just a C compiler :)

Build

gcc -std=gnu17 -Wall -Wextra -O2 ./game.c -o game

Play

./game

Implementation Stages

Stage 1

• Non-canonical input mode
• Turning off echo
• Proper reset on exit (both for normal exit and abnormal exit)
• Rudimentary game loop
• Grab the arrow keys
• Print them out (e.g. RIGHT)

Stage 2

• Empty level with borders
• Player can walk around within the borders

Stage 3

• Optimize rendering
• Optimize game loop

Stage 4

• Load up level from a file

Stage 5

• Gameplay

Stage 6

• Tests

Stage 7

• Rendering
• Colors
• Animations?

Gameplay

Game Elements

@ - Player Character
X - Wall
$ - Gems / Gold
O - Rock
. - Earth
  - Space/Empty
E - Exit

Rules

• Player can dig a tunnel through Earth
• Rocks/Gems fall down if there is space below them
• Rocks/Gems falling on Player ends the game -> Lose Scenario
• Player entering Exit ends the game -> Win scenario
• Player can't go through Wall, Rock
• Player can collect Gems

Composite Rules

This is stable

.O.
.O.

This is unstable -> Top rock rolls to the left

. O..
. O..

This is unstable -> Top rock rolls to the right

..O .
..O .

However, this is stable

.O ...
XX XXX

Rocks and Gems behave similarly in most of the time. For example, a Gem can kill the player if it falls on its head.

Player can push a rock horizontally if there is empty Space behind the Rock. In the scenario below, the Player can push the rocks right or left.

.. O@O ..
.........

General Game Requirements

Display Graphics

• Low resolution
• ASCII characters (subpixels, textures)
• Colors (foreground, background)
• Move the cursor's position freely

Input Handling

• Canonical Mode - line based
• Non-Canonical Input Mode - More control over input
• RAW Input Mode
• Turn off Echo

Sound and Music:

• :(
• Terminal Bell - NO

Toolbox

• man 3 termios
• ANSII Escape Codes - https://en.m.wikipedia.org/wiki/ANSI_escape_code

ANSI Escape Codes

FG Color

Paremeters: R G B

printf "\x1B[:38;2;R;G;Bm"

BG Color

Parameters: R G B

printf "\x1B[48;2;R;G;Bm"

Moving the cursor

Move Cursor To (x, y) - Upper Left Corner is (1, 1) Paremeters: X Y

printf "\x1B[Y;XH"

Clear Screen

printf "\x1B[2J"

Hide Cursor

printf "\x1B[?25l"

Show Cursor

printf "\x1B[?25h"

Reset Colors

printf "\x1B[m"