Snake++

A continuation of Gnarwhal's submission for Ludum Dare 40

How to Play

The game requires at least Java 8 to run.

To download the game, go to the Releases tab and download the latest release.

Controls:

• WASD - turn the snake
• Arrow keys - also turn the snake
• Space - retry/next level
• R - restart level

Making Levels

It's Super Easy

all of Snake++'s resources are easily accessible and modifiable to you from the res/ directory. You don't even need to have to build the project to modify it's resources. You can just grab the release and start modding.

If you made a good level that you would like to share, please make a pull request so it can be added to the project. I'd love to see what you can create.

Debug Mode

When developing levels, it will help to launch the game in debug mode. You can do this by providing the argument --debug or -d to the jar when you run it. In debug mode, the game loads the level from disk each time it starts. This way, you can make changes in the level and see it reflected in the game without having to restart. You may also provide the -l {number} or --level={number} flags to have the game start on a certain numbered level.

Debug mode also introduces new controls for selecting a level. On the retry or continue screens, you may press the , or . keys to move backwards or forwards a level respectively. Space always restarts the current level.

Level Format

Each of Snake++'s levels are housed in the res/level/ directory. Levels consist of a top level folder and some contents. One level per subfolder of the res/level/ directory. There is one special level named menu which is diplayed behind the menu of the game. The rest of the levels follow the naming format level{number} where number is the sequential number of the level. In the game, levels will be played in the order of their number.

There is no hardcoded number of levels in the game. You can add or delete as many as you want.

Proper level folder structure

data.txt

Within each level folder is a file called data.txt. This file defines some additional parameters about the level apart from its physical construction.

Each line in data.txt is formatted as {propertyName} = {value}. The following is a guide to the required properties:

• snakeSpeed An integer defining the initial speed in tiles per second that the snake moves
• snakeLength An integer defining the initial length of the snake
• palette The colors used to render the level, the format can be found in the output of http://dev.thi.ng/gradients/
• wrap How to access the level out of bounds. false means the level will be bounded by walls. true means you can exit one side of the level and come out the other.

Example data.txt:

snakeSpeed = 7
snakeLength = 10
palette = [[0.241 0.158 0.987] [0.788 0.758 0.595] [1.136 1.551 0.674] [4.059 2.529 3.709]]
wrap = false

music.wav

This file music that plays during the level. It should be in the wav format. No other configuration needed than that.

level.png

Now we get the interesting part. This file visually defines the layout of the level. It is recommended that you use a capable image editor where you can finely control each of the three color channels. Note that this is the part where the most new features are going to be pumped into. The format may change with future development.

The size of level.png is the size of the level in game. Each pixel represents one tile. The color of the pixel defines what kind of tile it is, and some additional data about the tile. The following is a guide on which colors correspond to which tiles.

	Color	Tile	Description
	0x000000	Blank	Nothing here, passable by the snake
	0xffffff	Wall	Not passable by the snake
	0xff0000	End	The exit to the level
	0xff7f00	Speed Up	A powerup that is collected to boost the snake's speed
	0x0000ff	Length Up	A powerup that is collected to boost the snake's length
	0xffff00	Speed Down	A powerup that is collected to decrease the snake's speed
	0x007fff	Length Down	A powerup that is collected to decrease the snake's length
	0xff00ff	Switch	Changes the level state from "on" to "off", affects on/off blocks
	0x007f7f	On/Off Gate 1	Passable only when state is "off", controlled by switch
	0x7f0000	On/Off Gate 2	Passable only when state is "on", controlled by switch
	0x007f00	Apple	Collect enough to pass through an apple gate

More Complicated Tiles

Some tiles are defined by more than just a single color. One of the channels is used to define data about the tile.

	Red	Green	Blue	Tile	Description
	0x00	0xff	0 - 3	Start	Starts the snake in a direction specified by the blue channel (see Direction Codes)
	0 - 255	0xff	0x7f	Apple Gate	A gate which is only passeble after a number of apples specified by the red channel have been collected
	0x7f	0 - 3	0x7f	One-Way Gate	A gate which is only exitable from the direction specified by the green channel (see Direction Codes)

Direction Codes

• 0 - right
• 1 - up
• 2 - left
• 3 - down

Example Level Image

This image contains every type of tile. You can find it in the project as level-example.png.

Building and Running

This project uses Kotlin v1.8.22, LWJGL v3.3.2, JOML v1.10.5

1. Open the project in JetBrains IntelliJ IDEA
2. It should automatically setup the Gradle project
3. Click on the build dropdown and then Edit Configurations...
4. In the popup menu hit the + icon to Add a new configuration
5. Add a new Gradle configuration
6. In the Run box type in run build
7. Hit Apply
8. Then hit the green triangle run button

Additionally, if you want to launch in debug mode, in the Run box you can instead put build run --args='--debug --level=5' (or the number of whatever level you want to test)