pmarreck/retrocube

My Nixified version of `leonmavr`'s spinning cube animation via very basic ray tracing on the terminal. Rendered in ASCII.

⬛ retrocube ⬜

Spinning cube animation via very basic ray tracing on the terminal. Rendered in ASCII.

                    +==
                ++======
             +============
          ==================
      ========================
   +===========================..
   ||+=====================.......
    ||+=================..........
    +||||===========...............
     +||||||==+.....................
      +||||||........................
       +||||||.......................
       +||||||~.......................
        +||||||....................~.%
           |||||...............~.
            ||||~..........~..
               ||.........
                ||....~

Requirements

1. ncurses
   On Debian-based systems it's installed with:

apt-get install libncurses-dev

On Arch-based systems it's installed with:

pacman -S ncurses

2. gcc

This implementation

In human language, the graphics are rendered by the following algorithm:

rows <- terminal's width
columns <- terminal's height
// a face (surface) is a plane segment (x, y, z) restricted within 4 cube vertices
initialise a cube (6 faces)
for (r in rows):
    for (c in columns):
        z_rendered = +inf
        for (surface in cube's faces):
            find z(c, r)
            if (z < z_rendered) and ((c, r, z) in surface):
                z_rendered = z
                draw(c, r)

Development

The naming convention follows the one of stb.
Source files are found in src and headers in include.

You can compile the project with:

make

You can run the binary with (a list of command line arguments is provided in the next section):

./cube

You can delete the binary and object files with:

make clean

Usage

By default the program runs forever so you can stop it with Ctr+C. Below are the command line arguments it accepts.

Short specifier	Long specifier	Argument type	Default	Description
-sx	--speedx	float	0.7	Rotational speed around the x axis (-1 to 1)
-sy	--speedy	float	0.4	Rotational speed around the y axis (-1 to 1)
-sz	--speedz	float	0.6	Rotational speed around the z axis (-1 to 1)
-f	--fps	int	40	Maximum fps at which the graphics can be rendered (lower it if high CPU usage)
-r	--random	no argument	Off	If disabled, rotate at constant speed around each axis. Else randomly and sinusoidally.
-cx	--cx	int	0	x-coordinate of the cube's center in pixels
-cy	--cy	int	0	y-coordinate of the cube's center in pixels
-cz	--cz	int	0	z-coordinate of the cube's center in pixels
-s	--size	int	24	Length of cube's sides in pixels
-mi	--maximum-iterations	int	Inf/ty	How many frames to run the program for

This is what it looks like on the command line:

random speed	constant speed