Hebi 🐍

A highly customizable snake clone made in Rust with the Bevy engine, named after the Japanese word for snake, 蛇(へび).

Configuration

One of the things that sets apart Hebi from other snake clones is its rich configuration options. You can configure pretty much everything: the map, tick speed, food spawn rate, window scale, etc. You can even make your own custom color themes in addition to those provided! Keep in mind that Hebi is still very much a work-in-progress, so the names, behavior, and functionality of configuration options may change in the future.

To start configuring your game, create a config.toml file next to the Hebi executable.

Example config.toml

theme = "solarized_light"
seed = 42
food_ticks = 8

[map]
type = "corridors"
corridor_width = 2

Available configuration options

Name	Type	Default value	Function
theme	String	"dracula"	Sets what in-game color theme Hebi should use. For example, theme = "cavern" would load the theme file themes/cavern.toml. See Themes for more information on creating custom themes.
seed	u64	Random	Sets what seed should be used for deciding snake spawn locations, food spawn locations, and food colors. Since this is an unsigned number, it must be positive and less than or equal to 18446744073709551615.
map	Map	N/A	Sets the map data. See Maps for more info.
grid_scale	u32	36	Sets the number of pixels per grid square.
tick_length	f64	0.2	Sets the amount of time between in-game ticks in seconds. For a more challenging gameplay experience, try setting this to 0.15 or 0.1. For an easier gameplay experience for those with a slow reaction time, try setting this to 0.25 or 0.3.
food_ticks	u32	16	Sets the number of ticks between each food being spawned.
snake_spawn_segments	u32	2	Sets the number of segments the snake spawns with, including the head.

💥 Modifying this option from its default value may cause the game to crash. | | snake_segment_despawn_interval | f64 | 0.1 | Sets the interval between each segment despawning upon snake death in seconds. You can set this to 0 if you want the entire snake to despawn at once. | | snake_respawn_delay | f64 | 0.5 | Sets the delay in seconds between all segments despawning upon snake death and respawning. | | eat_audio | String | "eat.wav" | Sets the audio file for the destruction of the snake's head and segments. The source for the default audio file is jsfxr. For example, eat_audio = "munch.wav" (fictional file) would load the audio file assets/sounds/munch.wav. Both .mp3 and .wav files are supported. | | destroy_audio | String | "destroy.wav" | Sets the audio file for the destruction of the snake's head and segments. The source for the default audio file is jsfxr. | | spawn_food_audio | String | "spawn_food.wav" | Sets the audio file for when food is spawned. The source for the default audio file is jsfxr. | | spawn_snake_audio | String | "spawn_snake.wav" | Sets the audio file for when the snake is spawned. The source for the default audio file is jsfxr. |

Themes

Along with the provided themes dracula, solarized_dark, solarized_light, and cavern, you can create your own themes! To get started, create a new file my_theme.toml in the themes folder, and open it in a text editor. To start off with, you can copy in the theme settings for cavern:

walls = "222233"
background = "000011"
snake = "ddddee"
food = ["5599ff", "ffc455", "ff6f55"]

To change a color, replace any of the hex codes provided, and make sure to remove the leading #. For food, you can put in as many colors as you like. If you decide to only have one food color, make sure to wrap it on square brackets: food = ["5599ff"].

To actually use your theme, see Configuration and add theme to your configuration file. If the theme can't file can't be found, the game will run, but as the colors are missing everything will be magenta. Likewise, if a color is missing or incorrectly formatted in your theme file, it will also show as magenta in-game.

Maps

Hebi currently ships with three different map generation modes: default, corridors, and custom.

Default

The default map type is the simplest, and it is what runs by default without any changes to the configuration file. To begin modifying, add the following to your config.toml file:

[map]
type = "default"

To override the default generation values, see the following table.

Configuration options

Name	Type	Default value	Function
width	u32	17	Sets game grid width, including walls.
height	u32	13	Sets game grid height, including walls.
corner_walls	u32	2	Sets the width and height of the corner walls. If you don't want any corner walls and an empty map, just set this to 0.
corner_walls_offset	i32	2	Sets the offset on the x- and y-axes of each of the corner walls from their respective corners of the map.

Corridors

The corridors map type is the only (relatively) complex generation type in the game currently. It sets up a bunch of vertical (or horizontal) corridors in the map of varying heights to increase game difficulty. To begin modifying add the following to your config.toml file:

[map]
type = "corridors"

To override the default generation values, see the following table.

Configuration options

Name	Type	Default value	Function
width	u32	34	Sets game grid width, including walls.
height	u32	17	Sets game grid height, including walls.
horizontal	bool	false	Sets whether to generate the map horizontally instead of vertically.
corridor_width	u32	3	Sets the width (height if horizontal = true) of each corridor. Corridors at the end of the map may be wider. This shouldn't be set to less than 2, since 1-wide corridors are dead ends and cannot be exited by the snake.
corridor_height	u32	10	Sets the maximum height (width if horizontal = true) of each corridor. For more control, see wall_variance.
top_corridor_offset	i32	3	Sets the horizontal (vertical if horizontal = true) offset of the top row of corridors.
bottom_corridor_offset	i32	0	Sets the horizontal (vertical if horizontal = true) offset of the bottom row of corridors.
wall_variance	f32	0.5	Sets the variance in the height (width if horizontal = true) of each wall. For example, with the default values where corridor_height = 10 and wall_variance = 0.5, that means that the actual heights of the walls in-game can vary anywhere in the top 50% of the maximum height, e.g. anywhere from 5 to 10.

Custom

If you aren't satisfied with the provided map generators, you can make your own maps! To get started, add the following to your config.toml file:

[map]
type = "custom"
data = """
#################
#               #
#  >      >  <  #
#  #      #  #  #
#  #      #  #  #
#               #
#  > <   >      #
#  # #   #      #
#  # #   # ##v  #
#               #
#################
"""

In the data field is where you make your map. A space means empty space and a pound sign # means a wall. Additionally, you must place at least one snake spawn point. A power symbol (^) is an up-facing spawn, a lower-case V (v) is down-facing spawn, a less-than sign (<) is a left-facing spawn, and a greater-than sign (>) is a right-facing spawn.

Contributing

If you feel like there's something you'd like to add to the game, feel free to make a fork and submit a pull request! I'll try to review it as soon as possible. If there's an issue with how I've structured the code in the project and you feel like there's a better way, however, please make an issue instead. Hebi is a learning project for me to learn Rust and Bevy, and I'd like to implement most of the core changes myself.

If you want to create a custom map generation type, a good starting point would be looking at src/maps/default.rs. Once you've got your generator working, submit it with a pull request! The more variety in game maps the better.